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Mar 19, 2015: ×Cystocarpium roskamianum

We are very grateful to have a guest entry from Dr. Carl Rothfels, a postdoctoral fern researcher at the University of British Columbia (and soon assistant professor at Berkeley). Dr. Rothfels and a team of researchers recently published the following: Rothfels, CJ et al.. 2015. Natural hybridization between parental lineages that diverged approximately 60 million years ago. American Naturalist 185:3(443-442). The first photograph is shared by another member of the research team, Harry Roskam, while the latter two photographs are courtesy of Carl. Thank you Carl and Harry, for the write-up and photographs!

Today's plant featured on BPotD is an extraordinary fern from the Pyrenees mountains in France, which goes by the rolls-off-your-tongue name of ×Cystocarpium roskamianum (seen in the first photo, courtesy of Harry Roskam). This species was first noticed growing in a nursery in the UK, by a fern taxonomist by the name of Christopher Fraser-Jenkins. While it may not look that unusual to us, Fraser-Jenkins noted that this innocuous-appearing plant shared characteristics of two groups of ferns--the fragile ferns (Cystopteris, exemplified in the second photo with Cystopteris fragilis) and the oak ferns (Gymnocarpium, exemplified by Gymnocarpium appalachianum). These two genera are very different from each other (at least to people who study ferns!): Cystopteris species have elongate leaves, short compact stems, a unique hood-shaped covering protecting the sori (the "spore dots"), and tend to grow in cracks in cliff-faces and other inhospitable habitats, whereas Gymnocarpium species have triangular leaves elevated on tall stalks, long-creeping underground stems (rhizomes), unprotected sori, and grow in rich soil on forest floors. Until recently, many taxonomists didn't think that they even belonged in the same plant family. How could two groups of ferns be more different? And as we all know, very different things are not able to successfully mate with each other...

Fraser-Jenkins, however, was not dissuaded--in pretty much every feature he examined, the plant from the nursery was intermediate between Cystopteris and Gymnocarpium and it didn't produce viable spores, which is another indication that it could be a hybrid. In researching the plant more, Fraser-Jenkins discovered it had been collected in the Pyrenees by a Dutch horticulturalist, Harry Roskam, who had brought it into cultivation (it grows vigorously and although it is sterile, it can reproduce rapidly via its long creeping rhizome, rather like a strawberry would). To honour the collector, Fraser-Jenkins formally described this plant in a new hybrid genus, as ×Cystocarpium roskamianum (the rules of botanical nomenclature stipulate that the genus name for intergeneric hybrids must start with the "×" symbol and then portions of each of the putative parental genus names, here "Cysto" from Cystopteris and "carpium" from Gymnocarpium).

But is ×Cystocarpium roskamianum really a hybrid between Cystopteris and Gymnocarpium? To answer this question, a team including Fraser-Jenkins, Harry Roskam, and researchers from Leiden University in the Netherlands, Duke University in the U.S.A, and the University of British Columbia in Canada, turned to the fern's DNA. If the fern was a hybrid it might be expected to have DNA sequences from both its parents, and that's exactly what the researchers found (to the great surprise of at least some of them): at a given gene, half the ×Cystocarpium sequences matched those from Cystopteris, and the other half were from Gymnocarpium. The DNA data were even more specific than that--×Cystocarpium is a hybrid between the cosmopolitan species Gymnocarpium dryopteris (which was the mother in the cross) and a European member of the Cystopteris fragilis complex (the father).

More astoundingly, the researchers were able to determine that the hybridization event probably happened only once, and very recently (maybe within our lifetimes) and that the last common ancestor of ×Cystocarpium roskamianum's parents lived approximately 60 million years ago. In other words, each of the parents had been evolving independently from the other for around 60 million years before the hybridization happened. Sixty million years is a very long time for two organisms to retain the ability to interbreed--typically that ability is lost within a few million years at most. To put this duration in perspective, the ancestors of humans diverged from those of chimpanzees a mere five or so million years ago; the hybridization event that formed ×Cystocarpium is roughly akin to a human producing a hybrid with a lemur or an elephant with a manatee. The fact that Cystopteris and Gymnocarpium retained some compatibility with each other after that amount of independent evolution raises interesting questions on how new species are formed, and how this process might differ in different groups of organisms. For example, ×Cystocarpium and the other reported cases of deep hybridizations tend to involve ferns and other plants that don't use animals to assist with fertilization. If there is something about the ecology or genetic structure of these species that allows them to retain reproductive compatibility among populations for longer than other groups do, and thus to form new species more rarely, could this explain why there are only around 10000 species of ferns (and approximately 1000 gymnosperms, 1200 lycophytes, 12000 mosses, 9000 liverworts, and 100 hornworts) compared to the nearly 300000 species of flowering plants?

Daniel adds: Another account of this research is available via NPR: "Weird" Fern Shows The Power Of Interspecies Sex.

Dec 12, 2014: Dictyonema huaorani

Dictyonema huaorani

BPotD work-learn student Cora den Hartigh is the author of today's entry. She writes:

Dictyonema huaorani is a lichen I have been researching quite a lot this semester. For a directed studies project, I chose to investigate hallucinogenic lichens--a hybrid between popular lichenology and scientific enquiry. It was a lot more difficult than anticipated, but I finally turned in a short book, over a week late! That's just how it goes sometimes. Nevertheless, I contacted Michaela Schmull at the Harvard Herbarium, who was able to forward me this magnificent scan. Now I can share the story here!

This is a scan of the thallus, or vegetative structure, of Dictyonema huaorani. This specimen was collected in 1981 by Wade Davis and Jim Yost, two explorers in eastern Amazonian Ecuador conducting ethnobotanical research with the Waorani people. Yost had heard rumours of this lichen for seven years before finally locating this individual. To date, this is still the only known specimen in existence. As you can see by the label, this lichen was found growing on rotting wood near the confluence of the Quiwado and Tiwaneo rivers in Napo state. Known as nɇnɇndapɇ by the Waorani, the lichen has been used by "bad" shamans to curse others and also been noted to cause severe headaches. It was reputed to potentially have hallucinogenic properties.

The unidentified specimen was forwarded to Dr. Mason Hale, who suggested that it might be a species of Dictyonema, perhaps similar to Dictyonema sericeum. A conclusive identification would not be made for another forty years--this past November! A team of scientists sampled the specimen's DNA and found it to be an as-yet unrecognized species, which they named Dictyonema huaorani. Even more fascinating, they were able tentatively ascertain the presence of psychoactive compounds: tryptamines and psilocybin. Psilocybin is notably found in the infamous Psilocybe cubensis (though also in least 200 other species of fungi), but this is one of the first publications indicating psychoactive compounds in lichens!

Although no fresh material is available, the dried specimen hints at how stunning and ethereal this lichen might look. You can also get a good idea by taking a peek at some similar species, of which there are many! Just recently, a molecular study of Dictyonema glabratum revealed the taxon could be split into at least 126 different species. They make for a lovely colour palette!

Lichens are the result of a sort of pact struck between a fungus and something that can photosynthesize, usually an alga. Because the fungus (or mycobiont) cannot produce its own food, it relies on its photobiont partner for sugars. Algae, on the other hand, have a hard time taking up water and staying hydrated. A lichen forms when a compatible alga and fungus team up (see illustrations). The fungus will form a thick protective layer of hyphae called the cortex. Beneath the cortex is a layer of algal cells, photosynthesizing away, suspended above a loose mesh of more hyphae called the medulla. In some lichens, particularly foliose or fruticose ones, a lower protective cortex is formed below the medulla. This is not always the case, though. There are the jelly lichens, which are a jumble of photobiont and mycobiont without any sort of stratification, or lichens with photobiont packed together in cephalodia. Crustose lichens never have a lower cortex: instead, they fuse directly to their substrate. Some lichens are even able to re-assemble themselves in a few months if turned upside-down, moving all of the algae through the medullary layer to face the opposite cortex where they will be exposed to more light.

The lichen complex has been observed primarily among fungi in the Ascomycota, but about 1% of lichens have a basidiomycete as the mycobiont. The photobiont, too, can be a cyanobacterium instead of an algae. This occurs in roughly 10% of all lichens. Dictyonema is particularly bizarre because it is a basidiolichen teamed up with a species of Scytonema, a cyanobacterium!

You can read more about lichens via Lichens of North America or the delightful Ways of Enlichenment.

Dec 4, 2014: Daucus carota

Daucus carota

An entry from BPotD Work-Learn student Cora den Hartigh, who writes:

Today, we have a different sort of image from a Canadian photographer living in Munich, Germany. Anne Hoerter takes her subject apart and slowly reconstructs it with photographs, sometimes using up to 40 or 50 images to achieve a single piece that is alive with motion and depth. The graceful movement Anne was able to embody with this stunning artistic representation of Daucus carota, or wild carrot, took three months to produce. Thank you, Anne! You can see more of Anne's work at her website, Áine - Fine Art Photography.

Daucus carota is a familiar umbelliferous species known by many common names, including wild carrot, bishop's lace, and (in North America) Queen Anne's lace. It is a Eurasian and north African native that is widely naturalized in other temperate areas of the world. In North America, one hypothesis is that its initial spread was due to being carried across the continent by settlers in grain sacks. Described by Linnaeus in 1743 in Species Plantarum, Daucus carota has also been recognized widely in poetry and folklore. William Carlos Williams' personifying poem is one example. Williams refers to a purple 'mole' in the white inflorescence. This 'mole' is actually a single anthocyanin-rich flower coloured deep red or purple at the centre of the umbel. Presumably, this single flower helps attract pollinators, perhaps acting as a nectar guide. Another story explains this red flower as a speck of Queen Anne's "blood" dropped from a needle prick while sewing lace.

The little red flower is a particularly useful diagnostic character given that the plant's feathery leaves, floral structure and tall-standing growth habit are similar to a number of poisonous relatives: poison hemlock (Conium maculatum), water hemlock (Cicuta spp.) and fool's parsley (Aethusa cynapium) are counted among these! Unlike many of its toxic family members, Daucus carota tends to grow in dry open habitats and has solid hairy stems. When young, its roots are edible and smell like fresh carrots. With age the roots grow woody and the floral structure curls inward like a vase. I always look for those hairy stems and think of the ditty "Queen Anne has hairy legs"!

In many jurisdictions where the species has naturalized, Daucus carota is considered to be a noxious weed. Doug Larson's oft-cited quote, "a weed is a plant that has mastered every survival skill except for learning how to grow in rows", comes to mind. Brushing up against the leaves can, in some people, cause skin to be more susceptible to UV damage, but this plant can be exceedingly useful. As a companion crop, it boosts tomato production and cools lettuce; as a dyestuff, it imparts creamy tones. Medicinally, the plant dates back to early Greek and Roman writings for digestive disorders, kidney stones, skin tonics, aphrodisiacs, insecticides ... the list goes on. The seeds are also a tasty flavouring for soups and stews not unlike asafoetida; however, they should be consumed with some caution. A relative of Daucus carota, silphium, is thought to have been harvested to extinction for use as a contraceptive and general tonic in ancient Cyrene (Lybia today). So important was silphium that coins were imprinted with the image of the plant. This paper from Economic Botany provides some fascinating archaeological investigation, while Wikipedia gives a good overview. Experimental trials in rats have suggested that extracts from Daucus carota seeds have "...at a lower dose showed anti-implantational activity [of the fertilized ovum into the uterus], whereas higher doses caused fetus resorption. The main effect of the extract appears to be an abortifacient activity." Perhaps not ideal for dinner party soup stock.

Daucus carota has been featured once before on Botany Photo of the Day.

Oct 24, 2014: Viburnum betulifolium

A note to local readers before beginning today's entry: National Geographic photographer Frans Lanting will be presenting all-day in Burnaby tomorrow at the 2014 Abbotsford Photo Arts Club Seminar.

Following Martin Deasy's series from last week, we have another guest writer and photographer today. Patrick Phillips is a Plantsman and Head Gardener in the UK. He trained at the Cambridge University Botanic Garden and the Royal Botanic Garden Edinburgh, and shares this entry with us:

Every time I walk down the East Shrubbery, I am drawn to a mature Viburnum betulifolium which towers over me. At 4.5m (15 feet) high, it is one of the most eye-catching large shrubs in the garden. It is not its autumn colour that attracts me now (in fact, the leaves are still green) but instead the very heavy crop of juicy, bright red, spherical fruits which cover the plant. In fact, writing this in the late second week of October, the plant has been laden with fruit for at least a month and shows no sign of fading. Technically, the fruits are drupes (fleshy fruit containing a hard endocarp which contain a seed). Coupled with its floriferous display in mid-summer, this Viburnum stands out as a garden-worthy plant of great horticultural merit.

Viburnum betulifolium is a multi-stemmed deciduous, rounded shrub suitable for the back of a border where it can either stand out as an individual plant or as a backdrop to lower-growing perennials. As the epithet suggests, ("like the leaf of a Betula") the species is commonly known as the birch-leaved viburnum. The leaves show similarity to Betula in both the leaf shape and toothed edges. There is, however, great variation in the variety of toothed edges; some leaves are fully toothed and some partial. It flowers are highly conspicuous. Covering the entire plant in June and July, this local plant flowered spectacularly this year, with tiny, white, slightly fragrant, 5-petalled flowers in a corymb inflorescence.

Native to western and central China, including Yunnan, Viburnum betulifolium was introduced to Western cultivation by British born Ernest Wilson to the Arnold Arboretum in 1901 through seed collection and was later described by the Russian botanist Alexander Theodorowicz Batalin. Despite its ease of cultivation and accolade (Award of Merit given in 1926), it's surprisingly rare in cultivation and is a plant that should be more widely grown. It's suited to both a sunny and partial shaded situation on well drained slightly acidic soil.

Some literature suggests Viburnum betulifolium is used for ethnobotanical uses. Ju et al., in the 2013 article Eating from the wild: diversity of wild edible plants used by Tibetans in Shangri-la region, Yunnan, China reported "fruit is eaten fresh and used to prepare local wine" by indigenous people.

Taxonomically, Viburnum is in the Adoxaceae and contains about 165 species which are predominantly distributed in the northern hemisphere, though there are a few species scattered throughout Asia and South America. About half are used in cultivation, though outside botanic gardens and significant plant collections, it is sadly rare to find more than a handful of commonly grown species.

Oct 18, 2014: Fothergilla major

Before starting today's entry, a note to local readers -- there are still many apple varieties available for the second day of the Apple Festival tomorrow, including one of my favourites, the Salish apple.

Thank you again to Martin Deasy for guest-writing and photographing a series on the Hamamelidaceae. Martin, who trained at the Royal Botanic Gardens, Kew in its Kew Diploma in Horticulture program, concludes the series with this entry.

The bottlebrush-like inflorescences of Fothergilla major--unlike anything else in the Hamamelidaceae--are just one more example of the family's remarkable diversity of floral morphology. As with Parrotiopsis, what look like flowers are in fact pseudanthia--compound inflorescences that "mimic" individual flowers. What appear to be petals are in fact clavate (club-like) stamens with inflated filaments, up to 32 in each flower; numerous reduced flowers are packed together on a rachis to form a single inflorescence.

An upland species native to the highlands of the southeast U.S.A. (the Appalachians of North Carolina and Tennessee), Fothergilla major occurs at altitudes of up to 1000m, particularly on dry ridges. It grows into a small deciduous tree, to ca. 5m, often suckering from underground stems to form dense thickets. The relatively late (for the family) anthesis in late April-May likely represents an adaptation to the harsher climate at altitude (the other Fothergilla species--the less hardy Fothergilla gardenii--is restricted to the coastal plain of the south-eastern U.S., and flowers in mid-April).

Absence of petals is an inherited trait (symplesiomorphy) of tribe Fothergilleae, whose members exhibit a progression from insect- to wind-pollination. The two insect-pollinated taxa, Fothergilla and Parrotiopsis, are also both the most basal; the more derived taxa (respectively Parrotia, Sycopsis, Distylium and Distyliopsis) have adopted wind as the principal means of pollination.

The comparison of Fothergilla and Parrotiopsis is revealing: the two genera are extremely closely related; yet each has recruited a different organ as attractant, lending their inflorescences radically different appearances. Nevertheless, the infructescences are very similar--indeed fruit morphology is astonishingly highly conserved across the entire Hamamelidoideae, a subject for a future post.

Oct 16, 2014: Sinowilsonia henryi

Sinowilsonia henryi

Martin Deasy's series on the Hamamelidaceae continues today with its fourth entry. The fifth, and final entry, will appear on Saturday. Martin writes:

The monotypic genus Sinowilsonia is named for the prolific English plant hunter E. H. "Chinese" Wilson, immortalizing both his surname and his nickname (the prefix "sino-" means "pertaining to China"). The species was first collected for Western science from the wild in 1889 by the remarkable Irish plantsman Augustine Henry, and bears his name. The original herbarium voucher specimen he sent to Kew can be viewed digitally (or see Wilson's 1907 collection of the same species).

Sinowilsonia henryi is a medium-sized tree native to the mixed forests of central China. Its unisexual inflorescences--effectively a type of catkin--are numerous and highly distinctive. Both male and female catkins are ca. 5cm long at pollination, but the rachis of the female inflorescence elongates markedly after fertilization, attaining a final length of 20cm or more.

The photograph shows a fertilized female inflorescence in the process of elongating. Each flower bears twin pinkish-green styles and 5 greenish sepals on a swelling pistil. Sporadic rusty-brown stellate trichomes (a familiar Hamamelidaceae character) are also visible on close inspection. Adjacent are the exhausted male catkins, beginning to dessicate having released their pollen some time earlier.

Sinowilsonia's reduced flowers (lacking petals and either male or female sexual parts) are typical of wind-pollinated taxa, which do not require petals to attract pollinators, but instead need to produce large volumes of pollen to maximize the chances of fertilization.

The characteristic inflorescences of Sinowilsonia (together with those of the other anemophilous Hamamelidaceae genera Sycopsis, Distylium and Parrotia) give some insight into why the Hamamelidaceae were historically closely aligned with other families of wind-pollinated catkin-bearers (the artificial grouping dubbed the Amentiferae). Systems such as that of Engler & Prantl treated them as neighbours to e.g. Fagaceae, Betulaceae, Juglandaceae, Urticaceae and Platanaceae, and despite almost immediate dissent, these relationships proved surprisingly slow to be dismantled.

More sophisticated morphological, and later molecular, taxonomy made clear that the reduced flowers found in wind-pollinated catkins were highly derived--that is, they did not represent a "primitive" ancestral state, and were therefore of little use in drawing conclusions about evolutionary relationships between taxa. Fragments of the Amentiferae are now widely scattered within the Fagales, Rosales and even Proteales. The Hamamelidaceae, meanwhile, are located firmly within order Saxifragales (the apically unfused bicarpellate pistils, and twin styles, are highly diagnostic).

In fact, within the Hamamelidaceae alone, wind pollination has evolved several times, in each case from an ancestral state of insect pollination. Thus most of Hamamelidaceae's anemophilous genera are found within tribe Fothergilleae, whereas Sinowilsonia has evolved separately within tribe Eustigmateae.

Oct 15, 2014: Hamamelis virginiana

Hamamelis virginiana

Today, we have the third in the series on Hamamelidaceae guest-written and photographed by Martin Deasy. Martin writes:

The sight of Hamamelis virginiana with its tangle of bare twigs covered in yellow blossom is one of the most striking sights of the late autumn and early winter. Widely distributed in the deciduous forests of eastern North America, it forms a small, spreading tree with small branches. It is well known as the source of the witch hazel extract widely used as an astringent, obtained from a decoction of the stems.

Assigned its own tribe (Hamamelideae) within subfamily Hamamelidoideae, the genus Hamamelis is characterized by strictly 4-merous, hermaphrodite flowers, with long, ribbon-like petals that are circinate (rolled like a fire-hose) in bud. A whorl of 4 staminodes secrete a nectar reward for pollinators. The anthers have only one sporangium per theca, and each theca opens outwards by a single valve, rather as if the anther were releasing its pollen through a pair of car doors.

Unlike other Hamamelis species, which flower from late winter into early spring, Hamamelis virginiana flowers in the autumn, from October until Christmas (in the northern hemisphere), and is pollinated by insects (mainly small flies). Following pollination, the pollen tube penetrates downwards towards the base of the carpel, at which stage it ceases development and overwinters before growth is recommenced--and the ovule fertilized--in late spring. There is thus a delay between pollination and fertilization of up to 7 months.

A possible explanation for Hamamelis virginiana's eccentric phenology (flowering period) has been suggested by observations from the Ozark mountains, where the species overlaps in range with the later flowering Hamamelis vernalis. In unusual years in which both taxa flowered simultaneously, it was observed that, given the choice, insect pollinators strongly favoured Hamamelis vernalis. This raises the possibility that the displacement of its flowering period into the late autumn might represent an adaptive strategy allowing Hamamelis virginiana to avoid having to compete for pollinators with its more appealing relation. Even then, relying on insect pollinators during the coldest parts of the year proves very inefficient , one study finding the rate of fruit set to be less than 1% (ref: Anderson and Hill 2002).

The issue of the numerous disjunct distributions characteristic of the Hamamelidaceae has already been partly treated in yesterday's post on Trichocladus crinitus. Hamamelis offers another particularly good example. Of the five Hamamelis species, three are from eastern North America, while two are east Asian--the classic "Tertiary Relict" disjunct distribution that has fascinated and teased botanists since it was first noticed in the 18th century. As the climate cooled in the Oligocene (ca. 35mya-23mya), the high-latitude Tertiary flora seems gradually to have been forced southwards, ultimately into its present-day refuges of either eastern Asia or southeastern North America.

The original geographical area occupied by the northern Tertiary flora included territory now submerged beneath the Pacific, Atlantic and Arctic oceans--the so-called "land bridges" (though they should not be thought of as mere bridges: they constituted fairly permanent land in their own right). Asia and North America have historically been connected by a substantial landmass known as Beringia, and it seems plausible that the extant Hamamelis species may have differentiated from an ancestral population present in or around Beringia. In this context, it is striking that the Japanese hamamelis (Hamamelis japonica, from the islands of southern Japan) is more closely related to the American species than to the Chinese Hamamelis mollis.

Oct 14, 2014: Trichocladus crinitus

A continuation of the series guest-written and photographed by Martin Deasy, who is a British horticulturist based in Oxford, England. Martin writes:

The startlingly furry appearance of Trichocladus crinitus, or black witch-hazel, is caused by the presence of rusty-brown stellate trichomes (or hairs). These are a feature of practically all Hamamelidaceae species, but here are closely packed to form an unusually dense indumentum. The resemblance of the unexpanded opposite (or sub-opposite) leaves to pairs of rabbits' ears only emphasizes the impression of animal fur.

Trichocladus crinitus is endemic to the moist Afromontane forests of South Africa, where it is locally dominant as a constituent of the understory vegetation--the Afrikaans name onderbos translates literally as "undergrowth." The plant forms a large, rather open shrub or small tree up to 3m in height, and its hard, white wood gives it its local Xhosa name iThambo ("bone").

The tiny flowers are packed together in dense spherical heads. The photo shows flowers before and after the anthers have dehisced. The floral features can be easily made out: 5 green sepals with rusty-brown stellate trichomes on the outer (abaxial) surfaces, and 5 pale-pink petals with involute margins and stellate pubescence, again on the abaxial surface. The 5 pale pink stamens, and twin styles (green) can also be seen. The anthers release their pollen in an unusual manner: although the anthers are tetrasporangiate, each theca opens with a single valve.

Trichocladus crinitus is one of five species in a genus distributed from Ethiopia, down through East Africa to the Cape, and offers an interesting case study in biogeography and floristics. Early accounts of Trichocladus (e.g. Hutchinson 1933) noted its longitudinal north-south distribution on the continent, inferring dispersal into Africa southwards from an ancestral range in Eurasia.

However, it was subsequently noticed that Trichocladus's highly unusual mode of anther dehiscence--rare even among the rest of the angiosperms--is shared with a handful of Hamamelidaceae species restricted to Australia, Madagascar and Africa. Dubbed the "Southern Hamamelidaceae" (Endress 1989), the close genetic relationship of this group was subsequently confirmed by molecular studies, and circumscribed as tribe Dicorypheae (Li & Bogle 2001). The five constituent taxa are Noahdendron, Ostrearia, Neostrearia (Australia), Dicoryphe (Madagascar) and Trichocladus (Africa).

The disjunct distribution of the Dicorypheae aroused some interest, since the locations in which they occur map onto the remnants of the supercontinent Gondwanaland, which after an existence of several hundred million years, broke up in stages between 165mya and 50mya. The existence of a disjunct subgroup of closely-related and highly distinctive hamamelid taxa on vestigial Gondwanan landmasses suggested that the Dicorypheae may have originated in Gondwana, the surviving members arriving in their present situations by continental drift (or vicariance, to use the technical term).

The Hamamelidaceae is known to be an ancient clade (the fossil record dates back to at least the late Cretaceous, ca. 85mya), so this posited Gondwanan lineage was quite plausible. However, it would have made the Hamamelidaceae an exceptionally ancient angiosperm lineage, pushing the original diversification of the family well back into the mid-Cretaceous, prior to the disintegration of Eastern Gondwana.

Subsequent work has shown that the apparent Gondwanan distribution is a red herring. Tellingly, the Australian taxa occur in the extreme northeastern corner of the continent closest to Asia, where the relict Gondwanan rainforest was infiltrated by Asian taxa during the Miocene (5.4mya), when the collision of the Australian and Southeast Asian continental plates facilitated significant floristic exchange. Furthermore, molecular evidence has revealed the Dicorypheae to be embedded within a larger clade of overwhelmingly pan-Asian distribution, strongly indicating that the "Southern Hamamelidaceae" differentiated in Asia, arriving at their present positions by a process of dispersal.

Fossil evidence of Hamamelidaceae species from Antarctica--another Gondwanan remnant--might seem to throw a spanner in the works. But reports of fossil Hamamelidaceae pollen at Antarctic sites invariably turn out to refer to Altingiaceae, now split off as a separate family. In fact, the story of Trichocladus's evaporating Gondwanan history recapitulates an increasingly familiar narrative in which molecular dating techniques demonstrate that putative Gondwanan distributions actually result from much later dispersals out of the northern hemisphere (cf. Davis et al. 2002).

The plant shown grew for many years in the remarkable Temperate House at the Royal Botanic Gardens, Kew--the world's largest surviving nineteenth-century glasshouse. The House is currently undergoing a major restoration, and most plants (with the exception of a few large palms) have been moved to temporary quarters for the duration of the five-year renovation project due to be completed in 2018.

Oct 10, 2014: Parrotiopsis jacquemontiana

We start a series today guest-written and photographed by Martin Deasy, who is a British horticulturist based in Oxford, England. Martin trained at the Royal Botanic Gardens, Kew, where he spent three years studying for the Kew Diploma in Horticulture. Martin writes:

This is the first in a 5-part series on the witch hazel family (Hamamelidaceae), focusing mainly on subfamily Hamamelidoideae, the largest and best resolved of Hamamelidaceae's five subfamilies. The classification adopted is that of Li and Bogle (2001).

For a relatively small family (±140 species in 31 genera), the Hamamelidaceae exhibits remarkable diversity in floral structure and pollination syndromes. Most people will be familiar with the characteristic flowers of the common (American) witch hazel, Hamamelis virginiana (Daniel adds: or, similar to it, Hamamelis mollis), with its heads of 4-petalled, strap-like, fly-pollinated flowers. However, other Hamamelidaceae genera have very different blooms. Today's photo shows the pseudanthial inflorescence of Parrotiopsis jacquemontiana, in which the "flower" is in fact a compound floral structure imitating the appearance of an individual flower.

Parrotiopsis belongs to tribe Fothergilleae, which is characterized by the absence of petals. In this striking but rarely cultivated species, what look like "petals" are in fact white bracts inserted on the peduncle below the inflorescence. The central yellow head comprises numerous hermaphrodite flowers, each with ±15 stamens and a bifid style mounted on a tomentose ovary; the tiny sepals are scarcely visible, and petals are absent entirely.

Parrotiopsis jacquemontiana--the only member of the genus--is native to the northwestern Himalaya (India, Pakistan, Afghanistan), and forms a small, compact tree. Its sturdy wood is used to make walking sticks and furniture, while the pliable twigs are used for weaving baskets. The plant shown grows at the Royal Botanic Gardens, Kew (UK), from seed collected in 1983 in the Swat Valley, Pakistan, on a west-facing scree slope at 2700m-2980m.

The floral diversity of the Hamamelidaceae reflects the family's ancient lineage and widespread distribution (the family has been present on every continent except Antarctica, though glaciation wiped it out of Europe). The great age of this group of plants means that closely related genera have persisted in isolation thousands of kilometres--or even continents--apart. Since the evolution of pseudanthia represents a relatively local adaptation to specific pollinators, inflorescence morphology can vary even between closely related genera. Thus although most of tribe Fothergilleae are wind-pollinated (e.g. Parrotia, Sycopsis, Distylium), their close relations Fothergilla and Parrotiopsis are pollinated by insects. The only bird-pollinated hamamelid genus, the distantly related eastern Asian Rhodoleia, likewise has a pseudanthial inflorescence.

Jul 12, 2014: Pereskiopsis aquosa

Another entry from Taisha, who writes:

Today, we have several photographs of Pereskiopsis aquosa from retired Garden staff member, David Tarrant. Thanks for sharing, David! David mentioned in his email to us that this is currently flowering in his garden after the commencement of summer rains in San Miguel de Allende, Mexico. He recounted that he had found a plant blooming in a garden trash pile about four years ago, and then took a cutting. The cutting formed a small rangy three-stemmed shrub about a metre in height. His plant now produces these buttercup yellow blooms, but David notes that like so many other cacti, the flowers only last a day.

In the email, David points out that it difficult to find anything written about this cactus species. He was right! This species is endemic to Mexico. It is distributed in the states of Jalisco, Colima, and Nayarit where it grows in tropical deciduous forests between elevations of 300-1800 metres. I also managed to dig up a bit about the evolution of the subfamily this species belongs to, the Opuntioideae.

The leafy habit of Pereskiopsis aquosa is curious, and the evolutionary history of leaf characters in the subfamily Opuntioideae is of interest (as well as below-ground storage morphology). This species-rich subfamily (the second most speciose subfamily in the Cactaceae with ~350 members) has a wide diversity of leaf and ground storage organ characters. Most genera in the subfamily possess early deciduous terete leaves that can be up to 2cm long, but are often much shorter. However, the genera Austrocylindropuntia, Quiabentia, and Pereskiopsis have persistent leaves. In addition to being described as distinctively persistent, the leaves of Pereskiopsis are flat, fleshy, ovate to spathulate, and up to 8cm long and 5cm wide.

The possession of persistent leaves within Opuntioideae, a family that is marked by stem-succulence, has given rise to some theorizing that the ancestral opuntioid was similar to either Austrocylindropuntia, Quiabentia, or Pereskiopsis. Others, however, have suggested that because of the reduced vasculature (transport tissue) in the persistent leaves within these genera relative to the relictual cactus leaves of earlier diverged Pereskia, that these persistent leaves are instead a derived character that actually represent an evolutionary reversal from within an ephemeral-leaved ancestral lineage. Based on the results of a character state reconstruction of ancestral leaf habit for the Opuntioideae, performed by researcher M. P. Griffith, the latter hypothesis is supported. His results showed that there were at least two derived independent adaptations of enlarged, persistent leaves in the Opuntioideae. Griffith explains that although most cacti possess a suite of morphological and anatomical adaptations for survival in arid regimes (such as stem-succulence), not all cacti may benefit. In areas where aridity is not the absolute limiting factor in growth (such as the habitats of Pereskiopsis, Quiabentia, and Austrocylindropuntia) increased surface area and photosynthetic capacity is actually adaptive.

Instead of Pereskiopsis, Quiabentia or Austrocylindropuntia representing the early morphology of Opuntioideae, Griffiths suggests that the early morphology of this subfamily may be best represented by the genus Maihueniopsis sensu lato (in the broad sense). The untenably monophyletic Maihenueniopsis is the deepest lineage within the Opuntioideae, and is characterized by being early deciduous, globular-stemmed, diminutive, and often geophytic. This genus, along with Puna, possess many characters that are plesiomorphic (ancestral) for the subfamily Opuntioideae. Some other hypotheses have suggested that the earliest Opuntioideae were true geophytes, though this remains unresolved. (see: Griffiths, M. P. (2009). Evolution of leaf and habit characters in Opuntioideae (Cactaceae): reconstruction of ancestral form. Bradleya. 27:49-58).

Jul 3, 2014: Amelanchier canadensis and Gymnosporangium sp.

Amelanchier canadensis and Gymnosporangium sp.

Taisha is again the author, and she writes:

Long-time BPotD reader and occasional contributor Wouter Bleeker of Ottawa, Ontario, Canada sent along today's photograph. It shows the fruits of an Amelanchier canadensis plant infected by a species of rust fungus from the genus Gymnosporangium. Thanks for sharing again, Wouter.

Rusts (order Pucciniales) are obligate plant parasites, i.e., they require plant hosts. Species of rusts often have multiple means of reproduction, each associated with a different stage in the life-cycle. Up to five different mechanisms for bearing spores (spermagonia, aecia, uredinia, telia, and basidia) are known for some species. These species of rusts require two specific and unrelated host vascular plant species: an aecial host (for spermagonia and/or aecia) and a telial host (for uredinia, telia, and basidia). Rust fungi taxa that require two hosts are called heteroecious. Some taxa, however, carry out their full life-cycle on only one host species (macrocyclic). Other rust species simply reproduce asexually with a single repeating life stage. More variations on the pattern include microcyclic (having only the telial and basidial stages and live on aecial hosts of macrocyclic relatives) or demicyclic (missing the uredinial life stage).

The Gymnosporangium clade has an array of life cycles (gif), host taxa, and degrees of host-specificity. Gymnosporangium species have a demicyclic life cycle, with most alternating between members of the Cupressaceae as a telial host (telia are gelatinous due to long pedicels of teliospores absorbing water in spring rains), and species from the Rosaceae supertribe Pyrodae (PDF) as aecial hosts (see: Novick, R. (2008). Phylogeny, taxonomy, and life cycle evolution in cedar rust fungi (Gymnosporangium)(Doctoral dissertation). Retrieved from ProQuest Dissertations and Theses. (3317188)).

In the above photograph, the Gymnosporangium species is parasitizing a member of the Pyrodae, Amelanchier canadensis. This deciduous shrub species has a number of common names including shadbush, serviceberry, and juneberry. When members of the genus Amelanchier are infected by species from Gymnosporangium, symptoms include brownish-orange spots on leaves and distorted fruits with horn-like protrusions.

According to the Horticulture Diagnostic Laboratory at Cornell University (PDF), of the 36 species of Gymnosporangium that occur in North America, only three are significant in the northeast area to warrant concern. The three species includes the cedar-apple rust (Gymnosporangium juniperi-virginianae), quince rust (Gymnosporangium clavipes), and hawthorn rust (Gymnosporangium globosum). Unfortunately, we're unsure which species is shown in the photograph submitted, but it could be quince or hawthorn rust. This is inferred from Penn State's fact sheet on cedar apple and related rusts. Both publications mention that the best way of preventing cedar rust diseases is to simply avoid planting alternate hosts close together. Planting resistant cultivars is another strategy. These management means should be employed before considering the use of fungicides.

May 14, 2014: Artocarpus camansi and Artocarpus altilis

Let's just say that the errors are piling up re: the software upgrade for BPotD, but at least some attempts at resolution will be made soon. On to more pleasant things: Taisha wrote today's entry:

Today we have photographs of two species from the genus Artocarpus of the Moraceae (the fig or mulberry family). These photos were sent in to us by frequent BPotD contributor Ian Crown, owner of the Panoramic Fruit Company. Thanks for sharing Ian!

The first photo shows the two side by side, with Artocarpus altilis on the right, and Artocarpus camansi on the left. The other two images are of Artocarpus camansi (in habit and a cross-section of the fruit). Artocarpus is from the Greek artos for "bread" and karpos meaning "fruit". Artocarpus is a genus of about 60 species. Growing as either evergreen or deciduous trees, the genus occupies the hot, humid, regions of tropical southeastern Asia and the Pacific Islands. In addition to being used as a food source due to the large edible fruits, some species within the genus are also used in folk medicine or as a source of timber.

Artocarpus altilis, or the breadfruit, originated in the western Pacific in New Guinea and associated islands, with the Bismarck Archipelago being the centre for diversity for wild-seeded forms. According to Breadfruit: Artocarpus altilis (Parkinson) Fosberg by Diane Ragone, in the late 1600s European explorers traveled to the Oceanic region and were impressed with the fruits of Artocarpus altilis. With a new source for food for hungry sailors, and the potential to feed inhabitants and slaves in the West Indies, Europeans began disseminating this species. Cultivars from Tahiti were transported to other Pacific Islands, the Philippines, and, later, to the Caribbean with Captain Bligh on his second expedition to the West Indies (the first was unsuccessful due to mutiny). This species is now common in many tropical regions, including the Caribbean, Central and South America, and coastal West Africa.

Breadfruit is a large evergreen tree that reaches a height of 15-20 metres. The bark is smooth and light-coloured, and internally the tree has latex present in all parts. Two large stipules enclose the terminal bud and may reach up to 30cm at maturity--later yellowing and falling with the unfolding of thick, dark-green leaves or emergence of the inflorescence. The fruits of this species are known as a syncarp--a composition of many individual fruitlets (1500-2000) attached to one central core that contains numerous latex tubes and large vascular bundles. The edible portion of Artocarpus altilis is the persistent perianth of each flower that grows and becomes fleshy after pollination. The rind of the fruit is the hardened surface of each flower, which is somewhat smooth with scars remaining where the stigmas protruded. This species may have no seeds to many, depending on the variety.

Artocarpus camansi, or breadnut, naturally occurs in the Philippines, New Guinea, and possibly the Moluccas and is rarely seen anywhere else in the Pacific Islands. Introduced to other tropical areas by Europeans around the end of the 18th century (there are contradictory reports on the dates), the breadnut is now widespread throughout the Caribbean, parts of Central and South America, and coastal West Africa. Breadnut trees are also large, growing up to 20 metres tall. The fruits of these species, also a syncarp, have a spiky skin and hold numerous seeds--making up for 30-50% of the fruit mass. Birds and flying foxes that feed on the flesh spread the seeds of the breadnut through dropping the inedible portions.

Other comparisons between the two species: Artocarpus altilis has broadly obovate to ovate leaves that are deeply pinnately-lobed with a smooth blade that has few to many pale reddish hairs, particularly on the midrib and veins, while Artocarpus camansi has pinnately-lobed leaves that are densely pubescent on upper and lower surfaces, midribs, and veins.

The (USA) National Tropical Botanical Garden in Hawai'i contains the Breadfruit Institute. Dr. Diane Ragone and her team at the institute promote the conservation and use of breadfruit for food and reforestation. They manage the largest and most extensive breadfruit collection in the world. In addition, they are engaged in initiatives to respond to global food security issues through developing partnerships to make breadfruit varieties available as a resource for agriculture, agroforestry, and reforestation.

Mar 6, 2014: Petrea volubilis

Another thank you directed toward retired UBC Botanical Garden staff member David Tarrant for sharing some of his photographs from Mexico. Today, the species is Petrea volubilis. David writes: "Petrea volubilis is a woody vine species native to Mexico and Central America. Its tough ovate leaves feel like sandpaper, hence one of its common names: sandpaper vine! The flowers are exquisite, borne on arching pendant racemes with equally showy bracts. The bracts last a little longer than the actual flowers, making for a showy garden plant".

Petrea volubilis is also know by other common names including queen's wreath and purple wreath. David noted its native range, but it is widely cultivated in tropical regions for outdoor ornamental use or temperate regions with overwintering indoors.

The genus is named in honour of Robert Petre, 8th Baron Petre, a noted horticulturist and botanist. Surprisingly, the name Petrea was suggested in 1732 or 1733, when Petre was only twenty years old (a specimen was first collected for Western science in 1732 by William Houston, who suggested the name). Linnaeus continued to use the name and formally applied it in his 1753 Species Plantarum, designating Petrea volubilis as the type specimen. Linnaeus also notes of Petrea volubilis: "...variolis correptus, longiori vita dignissimus, utpote qui Florae indicae domicilia exstruxit in Europa omnium splendissima. Perhaps someone with better Latin comprehension can interpret, but I muddle through this as "crooked vine, worthy of more cultivation, since it is always splendid when flowering in European greenhouses". I'd very much welcome correction, but don't bother using Google Translate, which isn't quite there yet with its Latin ("smallpox corrected a life worthy of the homes built in Europe, the splendid as that of Flora of India").

Jan 20, 2014: Dilatris corymbosa

Dilatris corymbosa

It's been many years since we've featured a species from the Haemodoraceae or bloodroot family. Australian representatives Conostylis setosa and Anigozanthos flavidus were both BPotDs in 2007. Thank you once again to retired UBC Botanical Garden staff member David Tarrant for sharing a photo of this African member of the family from his most recent excursion to South Africa. This plant was photographed near the Syncarpha vestita recently contributed by David as well.

Some references suggest an Afrikaans common name for this species of rooiwartel or red-root, but, like many common names, there are other entities that share the moniker (e.g., Bulbine latifolia). The 1804 Exotic Botany by Sir James Edward Smith suggests a common name of broad-petaled dilatris, but that name doesn't seem to be so common. David didn't mention a common name for it, but he did note that according to the local publication Common Wildflowers of Table Mountain and Silvermine, it is rare for the area. Endemic to South Africa, it seems to only be found in the south and west of the country (though other range maps show it as only being found in Western Cape province). Perhaps rarely observed, it is still considered a species of least concern by the Red List of South African Plants. Habitat-wise, David notes this photograph was taken in a low boggy area, within the general habitat of "woodlands and scrub".

iSpot southern Africa contains several other observations of this species. From the Silvermine Nature Reserve, here is a set of photos of Dilatris corymbosa with flowers coloured similarly to today's BPotD, as well as peach-coloured flower variant.

If you have academic institution access (or similar arrangement), you can also see a scientific description and scanned specimens of the species via JSTOR's Global Plants: Dilatris corymbosa.

Jan 17, 2014: Begonia susaniae

Begonia susaniae

And today's author is once more Taisha. She writes:

Today's photo is of a cultivated Begonia susaniae, taken in October of 2011. This image and the accompanying information about this begonia species was sent to us via email from Jacky Duruisseau, a begonia grower from France. Jacky aims to make begonias more widely known, and grows over 500 species himself from around the world (with two hundred of these having origins in continental Africa and Madagascar). Thank you Jacky for your photo and contributing greatly to the written entry!

The Begoniaceae contains two genera: Begonia consisting of about 1600 species and Hillebrandia, a monotypic (single species) genus endemic to Hawaii. With this many species in Begonia, taxonomists have divided the group into approximately sixty different sections of closely-related species. Begonia susaniae belongs to Scutobegonia, a section containing about 25 species from tropical or equatorial Africa.

Jacky notes that for begonia collectors, those that belong to the section Scutobegonia are rather mythical! He adds that this is partly because yellow-flowered begonias are rare. Also, those in this section are not easily grown in cultivation because they are self-infertile, making it difficult to obtain seed. Reproduction by vegetative cutting is the typical method of propagation.

Begonia susaniae is native to Cameroon, Equatorial Guinea and Gabon. Jacky comments that he often observes this species in the primary forest of the Crystal Mountains in northern Gabon, where it grows on mossy rocks and slopes near streams at an altitude of 200-900 metres. He mentions the yellow flowers with distinctive bullate (or blistered) foliage look like lights in the semi-dark forest. I am certain that real lights would be useful to find these plants, as Jacky notes the the difficulty in finding these flowers--having to walk, climb, cross rivers, and paddle to get to them in the darkened forests, all the while warding off mosquitoes and leeches! His friends are often amazed at the idea of him going to Gabon on holiday, but Jacky insists that it's rather the opposite; home is the holiday, given the challenge to see these plants in their native habitat.

Dec 19, 2013: Syncarpha vestita

Retired UBC Botanical Garden educator David Tarrant sent along these photographs from his November excursion to South Africa's Cape Floristic Region. Thank you, David.

Syncarpha vestita has the common name of Cape snow in English or [wit]sewejaartjie in Afrikaans. The genus is restricted to the Eastern Cape and Western Cape regions of South Africa, with about 30 species. In the evergreen fire-dependent shrubland known as fynbos, Cape snow is one of the many different shrubby species of this region.

David noted to me in his email that Syncarpha vestita has upright woolly grey-green leaves that overlap and large rounded composite flower heads with papery white bracts. From a distance, Plantzafrica describes these plants as "[resembling] flocks of beautiful, clean sheep". Plantzafrica (first link in the previous paragraph) also suggests that the pollinators for Syncarpha vestita are likely palynivorous (pollen-eating) beetles such as Spilocephalus viridipennis and Trichostetha capensis.

Syncarpha vestita is also described as a fire-ephemeral species. Seeds germinate after fires (fires are often lightning-induced). The seedlings grow rapidly, so this shrublet will often be a major component of the plant community for the seven or so years following a fire. After seven years, the dynamics of the plant community are such that Syncarpha vestita gets outcompeted by initially slower-growing species and begins to decline in number. The strategy for Cape snow is to then exist as dormant seeds, waiting for the next fire (it is akin to the hare from the tortoise and the hare stories). To read more about the germination of the seed after fires, see: Brown, NAC. 1993. Seed Germination in the Fynbos Fire Ephemeral, Syncarpha vestita (L.) B. Nord. is Promoted by Smoke, Aqueous Extracts of Smoke and Charred Wood Derived from Burning the Ericoid-Leaved Shrub, Passerina vulgaris Thoday. (PDF). Int. J. Wildland Fire. 3(4):203-206.

Aug 20, 2013: Aulacomnium turgidum

Bryophytes at Teardrop Glacier

Today's entry was written by Taisha:

Widely reported a few months ago, researcher Dr. Catherine La Farge and personnel from her lab at the University of Alberta recently documented the revival of bryophytes that had been buried under glacial ice. Radiocarbon dating of the mosses showed that the plants had been frozen since just prior to the Little Ice Age, approximately 400 to 615 years ago.

Today's photograph, provided by Dr. La Farge, shows Aulacomnium turgidum (or turgid aulacomnium moss) being revealed at the margin of the receding Teardrop Glacier in Sverdrup Pass on Ellesmere Island, Nunavut, Canada. From seven subglacial specimens sampled, 11 cultures displayed regrowth in the lab. The four taxa most consistently generated were Aulacomnium turgidum, Distichium capillaceum, Encalypta procera, and Syntrichia ruralis. For more on this story, see the news article from the University of Alberta, or read the journal article in PNAS: La Farge, C, et al. 2013. Regeneration of Little Ice Age bryophytes emerging from polar glacier with implications of totipotency in extreme environments. Proceedings of the National Academy of Sciences. 110(24):9839.

Dr. La Farge and her research team attributed the ability to revitalize the moss specimens that were entombed in ice for 400+ years to totipotency and poikilohydry. Totipotency means that a cell contains the mechanisms and information to divide and potentially differentiate into all of the ultimate cells of the organism (for humans, the zygote is an example). In mosses, totipotency in some (if not all) of the cells in the individual plant is a common phenomenon. Poikilohydry, or the ability to be dessicated and easily revived without physiological damage, is a strategy some bryophytes exhibit to adapt to irregular water supplies in their environment, like the high Arctic. Poikilohydric bryophytes typically lack mechanisms that control the gain and loss of water and consequently water may move in and out of the plant rapidly (see: Proctor, MC and Z. Tuba. Poikilohydry and homoihydry: antithesis or spectrum of possibilities? New Phytologist. 156(3):327-349).

Jul 9, 2013: Alcantarea galactea

Taisha is again the author of today's BPotD entry. She also organized this entry with Thiago S. Coser, of the Museu Nacional, Universidade Federal do Rio de Janeiro, in Brazil, who shared his photographs. Taisha writes:

The bromeliad Alcantarea galactea is a newly-described species from a small area of Brazil. Thiago Coser and his co-authors gave this species its name galactea due both to its visibility from great distances and to the meaning of the Greek word gala ("milky") in reference to its whitish colour. Because of the large size of the plants and the distinguishing colour (a result of a thick layer of epicuticular wax upon the leaves and bracts), populations of the plants can even be seen from aerial photographs of the area via Google Earth.

Plants of Alcantarea galactea form an infundibuliform (or funnel-shaped) rosette of leaves. They spread vegetatively by basal shoots. The yellow flowers are borne on lateral peduncles arranged distichously on a suberect or slightly pendulous inflorescence branch that is covered in bracts. The stamens are spread like that of another species from the genus, Alcanterea extensa, suggesting plants are pollinated at least partly by bats. Alcantarea galactea shows some similarities to other species within the genus, particularly Alcantarea odorata and Alcantarea patriae. However, the other related species are geographically isolated, and they differ in habit size, colour, inflorescence shape and size, bract morphology, and stamen organization.

Alcantarea galactea is the second largest of the approximately 30 or so other species within the genus, all of which are endemic to Brazil. Alcantarea galactea is rupicolous, meaning it grows amongst rocks. This species is found at elevations of 300-650m, under full sun on inselbergs of gneiss-granite. Presently, the hundreds of individuals within the population are known to grow only in the Alfredo Chaves municipality, an area that has been altered for coffee plantations, pastures, and granite extraction mining. Because of the decrease in forested area, the population of floral visitors acting as pollinators for Alcantarea galactea may be compromised. As such, this species may be considered an endangered species according to the IUCN in association with the restricted area of occurrence, small population size, and potential decline in suitable habitat.

To read the paper, see: Coser, T. S., Versieux, L. M., Wendt, T. 2013. Alcantarea galactea (Bromeliaceae), a giant Bromeliad from Brazil, with populations seen from the sky. Systematic Botany. 38(2): 339-343.

Feb 7, 2013: Aristolochia steupii

Bryant is the author of today's entry. He writes:

Thank you to Ingo of northern Germany for contributing today's photographs of Aristolochia steupii, a member of the Aristolochiaceae. Many members of the genus are commonly referred to as Dutchman's pipes, pipevines or birthworts. Aristolochia steupii is native to the thickets and woods of the Georgia portion (the country) of the South Caucasus.

Aristolochia is comprised of over five hundred species of woody vines (lianas) and herbaceous perennials. The flowers lack a corolla (ring of petals) and instead develop from an inflated and extended perianth consisting only of the calyx. The fruits form into dehiscent capsules containing many seeds.

Members of Aristolochia (often?) contain the carcinogenic aristolochic acid. Despite being listed as a Group 1 carcinogen, many members of Aristolochia have historically been used or are still being used in naturopathic medicine/ traditional Chinese medicine. Extracts from a few species of Aristolochia have been used as successful remedy for snakebites, where the compounds act by chemically deactivating the venom.

Nov 28, 2012: Psilocarphus brevissimus var. brevissimus

Psilocarphus brevissimus var. brevissimus

Today's photograph is courtesy of local field botanist Dr. Terry McIntosh. Terry took this image near Princeton, British Columbia in early September a couple years ago. Thank you!

Psilocarphus brevissimus has two recognized varieties: the Californian var. multiflorus and the far more widespread var. brevissimus. The latter can be found throughout western North America (see distribution map, but note incorrect absence from British Columbia), Baja California and parts of South America (Argentina and Chile). The reason for the disjunct (or widely separated) distribution isn't addressed in the resources I've read, but given the habitat requirements of the species, it can be imagined. Psilocarphus brevissimus is a species found along the drying margins of seasonally-inundated sites (like vernal pools and ditches). Long-distance seed dispersal via waterfowl or shorebirds seems the likely explanation.

Known commonly as short woollyheads or (my preference) woolly marbles, Psilocarphus brevissimus var. brevissimus is rare in some parts of its range, including British Columbia where it is a red-listed taxon restricted to the Princeton area. It is a low-growing annual, ranging from 2-10cm (1-4in.) tall.

Michael Charters' excellent California Plant Names: Latin and Greek Meanings and Derivations provides a meaning for Psilocarphus: the Greek psilos means "bare" or "naked" while karphos means "a splinter, twig, chaff, straw". This is in reference to the disk flowers in this genus not being subtended by chaffy scales (likely in comparison with a genus that is similar in appearance). The specific epithet means "very short" (same word root as "brevity").

A few additional photographs and illustrations are available via the Alberta Native Plant Council: Psilocarphus brevissimus var. brevissimus (PDF).

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