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Results tagged “written by taisha”

Sep 25, 2014: Cichorium intybus

Cichorium intybus

Another entry today that was written by Taisha prior to her departure. She wrote:

Thank you to Mats Ellting (aka Mellting@Flickr) for today's image of Cichorium intybus, or chicory. Mats uploaded the image to the Botany Photo of the Day Flickr Pool.

Cichorium intybus is a member of the Asteraceae or sunflower/aster family. The species is considered to be native to a wide swath of Eurasia (USDA GRIN), but it has also naturalized in other areas of the world where it has been introduced. Since this species has been cultivated globally for centuries for medicinal and culinary uses, its native range may be smaller than suggested by the Germplasm Resources Information Network (they do note, "exact native range obscure"). It was first transported to North America in the sixteenth century. The species can now be found in much of North America growing abundantly along roadsides, lawns, pastures, fields, and waste places. In some places (like British Columbia), Cichorium intybus is considered a noxious weed.

It is presumed that the ancient Egyptians were the first to cultivate this species, using it for medicinal purposes, a type of coffee, a vegetable crop, and occasionally for animal forage. Since then, it has been cultivated for many additional applications, and can be divided into types according to their use: "industrial" or "root" chicory is grown for the taproot to produce a coffee substitute or for inulin and fructans; "Brussels" or "witloof" chicory is grown in such a way that the roots are used for the production of etiolated buds or chicons by forcing; "leaf" chicory is used as a fresh or cooked vegetable; and "forage" chicory has been used since the 1970s to increase herbage availability in perennial pastures for livestock (see: Street, R., et al. 2013. Cichorium intybus: Traditional uses, phytochemistry, pharmacology, and toxicology. Evid. Based Complement Alternat. Med.. doi: 10.1155/2013/579319 ).

Cichorium intybus varieties have important medicinal uses. Different parts of the plant have been used medicinally for a variety of complaints such as surface wounds, swelling and inflammation, stomach ailments, and diabetes. Nonetheless, many of this species' constituents have not been studied for pharmacological potential. Chicory is reputed to have a long history of traditional therapeutic use in areas where it has been naturalized. According to Native American Ethnobotany by Daniel E. Moerman, the Cherokee made a tonic infused with the roots to treat nerves, and the Iroquois used a root decoction as a wash and poultice applied to chancres and fever sores.

Sep 12, 2014: Ipomoea purpurea

Ipomoea purpurea

Today we have an entry written by Taisha prior to her departure. Taisha wrote:

Ipomoea purpurea, or the common morning glory, is photographed here by Hugh Nourse (aka Hugh and Carol Nourse@Flickr). This photo was taken last month along the Blue Ridge Parkway in North Carolina. Many thanks for sharing, Hugh!

The bindweed or morning-glory family consists of over 1600 species, including Ipomoea purpurea. This species is an annual vine native to Mexico and Central America, but it has established elsewhere (e.g., in much of the USA and parts of Canada). This species is cultivated worldwide as an ornamental due to its large and showy trumpet-shaped flowers. The Mexican populations are monomorphic for flower colour (having only purple flowers), whereas the introduced populations in the USA are highly polymorphic for flower colour, ranging from white to pink to red and purple. Common morning glory possesses a number of weedy traits such as rapid and aggressive growth, high seed output, and extended seed dormancy in soil seed banks. Indeed, this opportunistic colonizer of disturbed sites is now regarded as a noxious weed in the southeastern United States.

Little is known about the timing and geographic origin of US populations. One hypothesis is that this species was introduced into the United States with maize cultivation ~4000 years ago and subsequently dispersed (called the "Maize migration hypothesis"). Another hypothesis is that it was introduced through Europe after European contact with the New World (termed the "European migration hypothesis"). In this scenario, Spanish explorers are suspected of collecting seeds of Ipomoea purpurea in its native range, sending them to Europe to plant in monastery gardens, and then later being introduced to colonial North America (north of Mexico) around 1700.

In a study by Fang et al., the researchers examined data from 11 loci and 30 Ipomoea purpurea accessions from the native range of the species in Central and Southern Mexico, and 8 accessions from the southeastern USA in an attempt to infer the precise Mexican origins of the southeastern USA populations.

Fang et al. assert that Ipomoea purpurea made its way to southeastern USA via Europe. They support the European migration hypothesis due to the low genetic diversity of the southeastern USA population compared to Mexican populations. This suggests a strong founder effect consistent with multiple founder events (e.g. Mexico to Europe and Europe to southeast USA). This is paired with a severe population bottleneck, which contrasts with the maize diversity in the USA. If common morning glory did migrate with maize after all, one would expect a larger diversity, given the shared demographic history of morning glory and maize. Fang et al. attribute the higher levels of flower colour polymorphisms in the southeastern USA compared to native Mexican populations to the desire for diverse flower colour, consistent with the introduction of this species from Europe to the USA for its horticultural appeal.

As for the origins of the southeastern USA populations, the researchers suggest the western Mexican populations (rather than the southern or eastern). They propose this origin based on their genetic assignment analysis, haplotype composition, and the degree of shared polymorphism. They note that the eastern Mexican populations likely did contribute genetically, but the western populations contribute in large part for three reasons. First, the western Mexican population has the highest diversity and thus a larger effective population size. Secondly, based on the European migration hypothesis, the early trade routes from Mexico to Spain were from the Valley of Mexico eastwards through Xalapa and onto the port of Veracruz. Lastly, they point out that the domestication of maize was ~9000 years ago in the Balsas River Valley, which is ~300km southwest of the Western population. If this were the case, then one would assume the colour variants of Ipomoea purpurea would have spread through Mexico and Central America along with maize culture, rather than the monomorphic purple form.

The researchers end by noting that although it is likely that Ipomoea purpurea first migrated to Europe before being introduced to the southeastern USA, there was substantial trade in the Aztec and earlier eras between the Valley of Mexico and regions to the east and south of Mexico, allowing for seed to be traded before the arrival of Europeans. Also, they mention that the accessions from the Valley of Mexico that show high similarity to the southeastern USA populations could have accompanied modern travelers or been reintroduced back to Mexico to be planted in gardens with likely escapes (see: Fang, Z. et al. (2013). Tracing the geographic origins of weedy Ipomoea purpurea in the Southeastern United States. Journal of Heredity. doi: 10.1093/jhred/est046).

Aug 29, 2014: Themeda triandra

Taisha completes the series on South African plants and biomes with this entry. It is also her last official day as a work-learn student with Botany Photo of the Day, though there are about a half-dozen other entries she has written that will be posted while the new students learn the ropes. Thank you, Taisha. She writes:

Today we feature the grasslands biome of South Africa with photographs of Themeda triandra, which is known as rooigrass in Afrikaans ("red grass"). These images (image 1| image 2) were uploaded to the Botany Photo of the Day Flickr Pool by Marie Viljoen@Flickr. The first image was originally posted on Marie's blog, where she later posted a poem about Themeda triandra by South African poet, Antjie Krog. Thanks again, Marie!

The grasslands, also known locally as Grassveld, is the largest biome within South Africa. It is found mainly on the high central plateau of South Africa as well as the inland areas of the Eastern Cape. This biome neighbours the savanna, thicket, and Nama Karoo biomes. This region is relatively flat, though it can vary between sea level and 2850m elevation. The semi-arid to arid grasslands have varying temperatures, with frost being common. Precipitation ranges between 600-1000 mm, with rainfall decreasing westward. The grassland occurs on a variety of soils from humic clays to poorly structured sands.

A single vegetative layer of grasses dominates the grasslands, although other species such as bulbs occur. There are two categories of grassland: sweet veld and sour veld. Sweet grasses occur on the semi-arid regions of the Eastern Cape in eutrophic soils, while the sour grasses can be found in the higher rainfall regions of Drakensberg on acidic soils.

Themeda triandra is a tufted C4-photosynthesis perennial grass occurring widely across parts of Africa, Australia, and Asia. In South Africa, Themeda can occur in the savanna biome, but is primarily found in the grassland biome in regions with rainfall between 500-950 mm and at elevations of sea level-1800m. When young, this grass is a green to blue-green colour tinged pink. It then turns red with age. Rooigrass at higher altitudes tends to be shorter and darker compared to plants at lower elevations. The spikes flower from October to July. Flowers may or may not long black or white hairs. The awned spikelets hang from clusters and are surrounded by reddish brown leaf-like spathes or bracts. Rooigrass does not vegetatively spread long distances, so it is instead an obligate seeder. The long hygroscopic awns twirl when wet, driving the barbed seeds into the ground. There, they will germinate if there is a layer of litter or pioneer plants. This species is noted to be resistant to fire, with resistance increasing if the site is not overgrazed and burnt at regular intervals to allow for regeneration.

Aug 28, 2014: Welwitschia mirabilis

The second-last in the plants and biomes of South Africa series is featured today. Taisha writes:

Today, we take a slight detour from South Africa, as this species is not present in the country. Welwitschia is found only in the Namib Desert of Namibia. However, the Namib Desert slightly extends into South Africa where it forms the country's sole area of desert biome. The Namib Desert is one of the smallest and oldest deserts in the world. I chose Welwitschia as it has not been featured on Botany Photo of the Day before and it was not easy to find a plant species in the Botany Photo of the Day Flickr Pool to represent this biome. Still, this species is an interesting representative for the desert. Daniel contributed these photographs of Welwitschia mirabilis from Huntington Botanical Garden.

As implied above, the desert biome occurs in only a small part of northwestern South Africa, primarily the Springbokvlakte area of the Richtersveld. The altitude is between 600 and 1600 m, which results in a slightly cooler climate than other true deserts (though it remains more climatically extreme than the succulent Karoo and the Nama-Karoo biomes). Temperatures can be hot, up to 45°C. Similarly extreme, temperatures can drop over 20°C from day to night. Winter temperatures can be as low as -12°C. Fog from the nearby Atlantic Ocean accounts for much of the precipitation, although there is some variable summer rainfall (~10-80mm annually). True deserts are largely sandy with low organic material in their soils.

The vegetation within the desert biome is typically annual grasses and other plants. After a season with rarely abundant rains, short annual grasses may grow, whereas in most years the annual plants persist as seeds. Some perennials may survive, particularly in areas associated with local concentrations of water.

Welwitschia mirabilis is a monotypic species of the Welwitschiaceae under the plant Division Gnetophyta--a small group of seed plants that have intermediate characteristics between gymnosperms and angiosperms. The oldest specimens of Welwitschia in the Namib Desert are thought to be more than 1500 years old, and recent fossil evidence suggest that Welwitschia was present during the Cretaceous (~112 million years ago). Some photos of the plant in habitat are available via Wikimedia Commons: the biggest known plant and a couple plants in the landscape.

This dioecious (male and female individual plants; male and female cones are shown above) evergreen species has a woody unbranched stem that is shaped like an inverted cone. The stem is surrounded by a bi-lobed crown of green photosynthetic tissue. There are only two opposite, persistent, ribbon-like leaves that grow continuously from a basal meristem and die off at their tips over time. Unique among all extant plant species, after the first two leaves form, the terminal bud dies and the apical meristematic activity is transferred to the periphery and base of the leaves. In other words, it has ever-growing persistent leaves, with the leaf ends being the oldest part of the leaf.

Aug 25, 2014: Bauhinia galpinii

Bauhinia galpinii

Here is entry number six in Taisha's South African plants and biomes series. She writes:

Bauhinia galpinii, known as Pride of the Cape or Pride of De Kaap, is featured today as part of the savanna biome. Even though the name may suggest it is from the Cape (de kaap= cape), it is actually named after the De Kaap valley in the northeastern region of South Africa. This 2007 photo was taken by frequent BPotD contributor, Bart Wursten (aka zimbart@Flickr), in Manica, Mozambique. In addition to South Africa and Mozambique, the species is also present in Zimbabwe. Thanks for sharing, Bart!

The savanna biome spans a large area over the lowveld and Kalahari regions of South Africa. Elevation ranges between sea-level and 2000 m. Summers are very hot and rainy in this region, with temperatures anywhere between 12 and 39°C. This is followed by a cooler dry season where temperatures range from 0-32°C. Annual rainfall varies from 235mm-1000mm in the biome, and some parts of it may be frost-free while others can have up to 120 days of frost/year. Many of the major soil types (PDF) are represented in the region, though soils are usually porous, quick-draining, and with a thin layer of humus.

The savanna has a distinguishable grass-dominated ground layer accompanied by the different densities of woody shrubs and trees (shrubs may be the most prolific plants in overgrazed areas). C4 grasses form much of the grass layer where there is a hot growing season (C4 photosynthesis is best-suited for heat), while C3 grasses tend to be in the majority in cooler, wetter parts of the biome. Many plant species are adapted to survive fires, and most will resprout from stem bases even after severe burning.

Bauhinia galpinii is a fabaceous shrub with two-lobed leaves and bright red-orange flowers. This species is traditionally used medicinally by the Venda (or vhaVenda) people of the Limpopo province. In Mahwasane et al.'s survey of indigenous knowledge on medicinal plants used by the traditional healers of Limpopo's Lwamondo area, the roots of Bauhinia galpinii are boiled and the mixture drunk to treat stomach worms or to improve sexual performance. They also add that the concoction can be used to make a soft porridge for stomach pains. The researchers further mention that other studies have claimed that this species is used for treating diarrhea and infertility (bark and leaves), for infertility using the roots, or for amenorrhea (seeds). Traditional healers (herbalists) of the vhaVenda use up to 16 species of herbs, trees, or shrubs within seven families for medicinal purposes. Those from the Fabaceae are used most frequently; other families represented were Annonaceae, Asteraceae, Ebenaceae, Orobanchaceae, Oxalidaceae, and Verbenaceae. Different plant parts are collected from the medicinal species, most often the roots (also the leaves, bark, flowers, or whole plant), and diversely prepared for treating the above illnesses as well as others, including stomach ailments, dysmenorrhoea and oedema (see: Mahwasane, S., L. Middleton, and N. Baoduo. (2013). An ethnobotanical survey of indigenous knowledge on medicinal plants used by the traditional healers of the Lwamondo area, Limpopo province, South Africa. South African Journal of Botany. 88:69-75).

Aug 22, 2014: Crassula ovata

Crassula ovata

Number five in the series on South African plants and biomes series from Taisha, who writes:

The informally-recognized thicket biome of South Africa is featured today with an accompanying photograph of Crassula ovata. This image is another shared via the Botany Photo of the Day Flickr Pool, and photographed by Sean Rangel@Flickr. Thanks for sharing, Sean!

The Albany thicket occurs along the Fish, Sundays, and Gamtoos river valleys in the eastern Cape, and moves west along the intermontane valleys of inland Fold Mountains and east into Maputaland-Pondoland Bushland and thicket. Annual temperatures range from 0°C to 40°C, with it being more extreme inland, and more moderate toward the coast. Annual rainfall is between 300-550mm per year, varying between inland and coastal areas, and valley mists are common on the coast. Soils are deep, lime-rich, sandy loams that are well drained and often have low moisture levels for extended periods of time.

The Albany thicket can be divided into three regions, each with unique vegetation patterns. The dry, inland areas of the Fish, Sundays, and Gamtoos Rivers are rather sparse, and have been classified as Valley Bushveld. This region contains both leaf and stem-succulent shrubs and a few characteristic woody species. Coastal area of these river valleys, known as Kaffarian succulent thicket, are extremely dense with ~90% canopy cover. These thickets are rich with species of spinescent shrubs, woody vines and succulents. Lastly, the intermontane valleys, know as Spekboomveld or Spekboom succulent thickets, are a dense shrubland dominated by Spekboom (Portulacaria afra) with other succulents, herbs, and grasses also occurring.

Crassula ovata is one of the most common crassulas occurring in South Africa. This well-branched succulent shrub occurs naturally on rocky hillsides from Willomore to East London, and north to Queenstown and KwaZulu-Natal. From a picture of the foliage, you may recognize that this as the commonly cultivated plant known as the jade plant or money tree. Many people grow these as container plants, both in and outdoors.

Like most Crassula species, Crassula ovata reduces water loss from its leaves by utilizing Crassulacean Acid Metabolism, or CAM. Part of the CAM biological process is that stomata are closed during the day to prevent water from evaporating, and instead opened at night to collect carbon dioxide (this is the reverse of how most plant species exchange gases, with stomata open during the day instead). The carbon dioxide is stored overnight in the form of crassulacean acids, which are then broken down during the day. This releases the CO2 for the photosynthesis process during the day. During extremely dry periods, Crassula species may undergo CAM-idling, where stomata are not opened during the day or night. Instead, the plants will recycle the CO2 within the cells. This leaves them unable to grow or develop new tissue, but the plants are able to survive the lack of water by losing very little of it during this time.

Aug 21, 2014: Cunonia capensis

Taisha continues with the South African plants and biomes series. She writes:

The forest biome of South Africa is up next. To accompany this entry, we have two photographs (image 1 | image 2) of Cunonia capensis (also known as the butterspoon tree, rooiels in Afrikaans, and umLulama in Zulu) from University of California Botanical Garden at Berkeley. These were uploaded to the Botany Photo of the Day Flickr Pool by James Gaither (aka J.G. in S.F.@Flickr), who has since passed away.

The smallest biome in South Africa, the forest biome covers less than .25% of the country. Still, it is divided into two regions: Knysna forest along the southern Cape coastline, and the Amatole further east inland. The Knysna-Amatole forests are part of the afromontane archipelago--discontinuous regions analogous to sky islands. Knysna occurs on gentle slopes between 5-1220m, while the Amatole Mountains lie between 700-1250 m. Rainfall and temperatures vary between ~500-1220 mm and ~10-25°C respectively with the Amatole Mountains being both wetter and cooler than Knysna. The soils of these forests are generally acidic and nutrient-poor.

The floristically diverse forests have some 636 and 649 vascular plant species recorded respectively. Evergreen trees primarily form a continuous canopy, covering layers of vegetation that include (but aren't limited to) lianas, herbaceous species such as ferns, and epiphytes. Because of the dense shade from the layers above, the ground layer is almost absent.

A species that can be found in this biome is Cunonia capensis, the tree featured in today's photographs. Cunonia capensis, of the Cunoniaceae, is a tree found along the coast and adjacent inland areas of South Africa. In the forest it may reach up to 10m in height, and about half that height in the open. The showy, scented flowers appear in February and continue through March. They are collected in cream-coloured spikes, as shown in the first photograph. The fruits are brown two-horned capsules that release fine, sticky seeds. Seeds are either wind-dispersed or may also stick to visiting birds that fly off with them attached to their feathers, legs, or bills. One of the more prominent characteristics of Cunonia capensis is the pair of stipules that enclose the growing tip of developing branches. They are large and are pressed together and look much like a spoon--hence one of the common names, butterspoon tree. The second photo shows this phenomenon, as well as additional images via the Fernkloof Nature Reserve site: Cunonia capensis.

Aug 20, 2014: Mimetes cucullatus

Here is Taisha again, with the third entry on South African plants and biomes. She writes:

Today we feature two photographs of Mimetes cucullatus, known as the common mimetes or pagoda or the red mimetes or pagoda. In Afrikaans, this species is known as rooistompie, or simply stompie. Rooi means "red", and stompie means "little stump". Retired UBC Botanical Garden staff member, David Tarrant, sent these images from his visit to Cape Town's Kirstenbosch National Botanical Garden last November. Thank you kindly, David!

The fynbos is a biome located in southwestern South Africa. It consists of two distinct vegetation groupings, the fynbos and the renosterveld. These regions together form over 45000 km2 of land, all above 300 meters in elevation. Renosterveld typically has fertile, fine-grained soils of silts and clays whereas fynbos has poorer nutrient quality. Rainfall occurs throughout the year and accumulates anywhere from 300-2000 mm annually. Fire is an important influence on fynbos community processes, and the region must burn every 6 to 45 years to sustain many plant species.

Mimetes cucullatus is an example of a plant that relies on fire for regeneration. This is the only species of Mimetes that is a resprouter (as opposed to only being a reseeder). After fire, plants regenerate from a large, woody, underground rootstock, whereas most others are killed by fire (unless they have a thick, corky bark and survive). Seedlings will also sprout post-fire when conditions are suitable.

Common mimetes is a widespread species. It is easy to distinguish from other members of the Proteaceae with its unusual tubular and wool-like flowers grouped in four perianth segments. In bud, the segments touch each other, but do not overlap. They then separate as the flower opens to expose the style equipped with a sticky pollen presenter. Stigmas on these perfect flowers are not receptive at anthesis, thus preventing self-pollination. Within each of the white tuft-like perianth segments rests a single anther. Colourful leaves surround each floret like a hood. After pollination by sunbirds or sugarbirds, a nut-like fruit develops. The seeds within the fruit have elaiosomes (grey-white oily protuberances) at either end. These eliaosomes attract ants, who collect the seeds to carry back to their underground nests. There, they eat the elaiosomes, but do no damage to the seeds. Seeds deposited in ant nests can remain viable for many years.

Aug 19, 2014: Pachypodium namaquanum

Pachypodium namaquanum

Second in the series on South African biomes and plants, again written by Taisha:

Pachypodium namaquanum is commonly known as halfmens (Afrikaans for "semi-human"), elephant's trunk, or elephant plant. This species is found in the Succulent Karoo. Drew Avery@Flickr took this photo back in 2009 at the Denver Botanic Gardens and shared it via the Botany Photo of the Day Flickr Pool. Thanks, Drew!

The Succulent Karoo biome extends down the western coast of Namibia and further inland and comprises two domains--the Namaqualand-Namib domain along coastal plain, and the Southern Karoo domain to its east. The altitude of this region is mostly below 800 meters, but may reach up to 1500 m. The temperature in the Succulent Karoo ranges from -4°C in the coldest month and can reach over 40°C at other times. Annual rainfall ranges from 20-400 mm and falls mainly in the winter months (summers are arid), with heavy fog supplementing the precipitation. Berg winds may also occur throughout the year. Soils of the succulent Karoo are much like the Nama Karoo--lime-rich, weakly developed soils on rock.

The vegetation in the Succulent Karoo is, as you may have deduced, dominated by succulents (particularly dwarf shrubby species)! There are many leaf succulents present in the Succulent Karoo, and annual displays of asters occur in the spring. Endemism is extremely high, with around 67 genera and over 1,900 species occurring nowhere else. Included amongst these endemics is Pachypodium namquanum, the species in today's photograph.

Pachypodium namquanum is a stem-succulent species of the Apocynaceae that can live up to 300 years or more. This species grows slowly and regularly, eventually attaining a tree-like appearance when mature at 1.5 to 2.5 m in height (see photos linked from the Wikipedia page: Pachypodium namaquanam). The stems are also covered in tubercles, from which spines protrude. The leaves are borne in rosettes and are distinctively wavy. Yellow-green flowers with red interiors appear from July through September and later develop into horn-like, dehiscent capsules enclosing wind-dispersed seeds.

The unusual appearance of the halfmens has made it one of the most famous and sough-after succulents in the world. One of the most intriguing characteristics is the bowing of the stem to the north. There are folklore interpretations of this phenomenon, however researchers attribute this nodding of ~45-65° to the low solar zenith angle during the winter months. They explain that during the winter, where conditions are more favourable for growth over summer, the low solar zenith angle may pose a potential limiting factor on plant growth. The 55° north incline, they explain, would maximize the solar irradiance on the plane of whorled leaves, of which most are also on an inclination to maximize irradiance. The researchers suggest that the slant northward may benefit the species by increasing net primary production, as well as increase tissue temperatures midwinter when the flowers and later fruits are developing thus minimizing the effects of late-season drought on reproductive output (see: Rundel, P., et al. (1995). Winter growth phenology and leaf orientation in Pachypodium namquanum (Apocynaceae) in the Succulent Karoo of the Richtersveld, South Africa. Oecolgia. 10(4):472-477).

Aug 18, 2014: Aloe broomii

Aloe broomii

Taisha begins a series on plants and biomes of South Africa today. She writes:

This photograph of Aloe broomii was uploaded to the Botany Photo of the Day Flickr Pool by MarieVijoen@Flickr--a frequent contributor sharing photos of flora from South Africa and New York. Thank-you, Marie! (and here is her weblog for further reading: 66 Square Feet (Plus)

South Africa has eight major terrestrial biomes (PDF): the Nama Karoo, succulent Karoo, fynbos, forest, thicket, savanna, grassland, and desert (see map). These biomes (large-scale biotic communities) each have distinct climatic and environmental conditions. Correspondingly, each biome has a flora and fauna with different adaptations.

The first biome in the series is the Nama Karoo. The Nama Karoo is an area on the central plateau of the western half of South Africa. The Nama Karoo is the second largest biome in the region and is divided into three main subregions: the Upper Karoo, the Great Karoo, and the Lower Karoo. The altitude is between 500 and 2000 m with most of the area between 1000-1400 m. Most of the rain falls in the summer months between December and March, and temperatures may reach over 30°C. In the mid-winter (July), temperatures may be below freezing. Shallow and weakly developed lime-rich soils cover most of the region.

The vegetation type of this area includes many dwarf shrubs and grasses. This area is not particularly species rich, although much of the flora is adapted to the local climatic extremes. One of these plant species is Aloe broomii, of the Xanthorrhoeaceae. This species is also known as the snake aloe in reference to its snake-like racemes. Aloe broomii has unique flowers—the buds are hidden from view by longer bracts, and only the stigma and styles peak out awaiting pollination by visiting bees, sunbirds, and ants. These pollinators are attracted by the nectar. The many light-winged seeds of Aloe broomii are dispersed by wind and may be consumed by small maize or rice weevils (Sitophilus spp.). Some farmers in the Steynsburg district will boil the leaves to extract a brownish fluid. This fluid may be used in a number of ways: to kill ticks, as a disinfectant, as an ear remedy for sheep, or given to horses in small doses to make their blood temporarily bitter, causing any ticks to disengage from the animal.

Aug 12, 2014: Castilleja lemmonii

Castilleja lemmonii

I've returned from two weeks of work in the field and two weeks of vacation, but here is another entry from Taisha today while I continue to catch up on correspondence. Taisha writes:

Thanks to Eric Hunt.@Flickr for this photograph of Castilleja lemmonii, or Lemmon's Indian paintbrush. It was taken in July of 2009 in an alpine meadow between California's Greenstone Lake and Saddlebag Lake, located in the Inyo National Forest of Mono County. Thanks, Eric!

Castilleja lemmonii is perennial species native to California. It is found in moist meadows in the southern Cascades and the Sierra Nevada at elevations of 1550-3700 m. Grey-green lanceolate leaves are held on an unbranched stem that can reach up to 20 cm in height. The inflorescence consists of a collection of pink to purple-red bracts that surround green tubular flowers.

Members of Castilleja are placed in the Orobanchaceae, but many older texts had them classified in the Scrophulariaceae. They are hemiparasitic, i.e., photosynthetic, but also receiving some nutrition from host plants. Castilleja species are noted to parasitize a wide range of plant species, and can also parasitize multiple hosts simultaneously. More specifically, Castilleja species are facultative root hemiparasites. Their roots grow until they touch the roots from another plant, whereupon they penetrate the roots with haustoria. The Castilleja receive water, fixed carbon compounds, nitrogen, other nutrients, and even secondary metabolites from the host.

Hemiparasites influence plant community dynamics and other trophic levels by a distinct suite of ecological traits. Most people may initially suspect that parasitic plants have mainly negative affects within a community, particularly with respect to their hosts. This is true to some degree where the parasitic plant competes with both host and non-host plants for light, water, nutrients, pollinators, and seed dispersers. However, according to some ecologists, parasites may actually increase the diversity within a community depending on whether or not the preferred host is the competitive, dominant species. If dominant, then its suppression of the dominant species may allow for other species' populations to increase. Hemiparasites are also sometimes considered mutualists. The litter of hemisparasites is considered to be nutrient rich, and as this high-quality litter rapidly decomposes it provides nutrients for co-occurring plants. It also supports a more diverse and active soil biota.

To read more, you may wish to look over a paper by Phoenix and Press from the University of Sheffield where they discuss several aspects of the influence of Orobanchaceae on community dynamics (see: Phoenix, G., Press, M. (2005). Linking physiological traits to impacts on community structure and function: the role of root hemiparasites Orobanchaceae (ex-Scrophulariaceae). Journal of Ecology. 93(1): 67-78). You can also read a summary of their paper written by a graduate student from the University of Washington last year.

Aug 7, 2014: Xerochrysum bracteatum

Xerochrysum bracteatum

Today we have a photo of Xerochrysum bracteatum, known commonly as straw flower or everlasting flower. This photo was taken by Anne Elliott (aka annkelliott@Flickr) back in May, and uploaded to the Botany Photo of the Day Flickr Pool. Thanks for sharing, Anne!

Native to Australia, Xerochrysum bracteatum (previously in the genus Helichrysum or Bracteantha) of the Asteraceae, can be either an annual or perennial species depending on conditions. Straw flower occurs in most states and territories of the country, along forest margins, in deserts, and in sub-alpine areas. This species grows up to a metre in height, has green-grey leaves, and produces its flowers from spring through the summer. The central disc of flowers is surrounded by an involucre of rigid, papery bracts of yellow, red, orange, pink, or white. The bracts retains their colour, hence the common name, everlasting flower. This species is commercially grown for the dried flower market, although it is also a long-lasting fresh cut flower.

Many cultivars of Xerochrysum bracteatum are available, and are easily grown in average, dry to medium, well-drained soils in full sun. Seeds can be sown indoors 6-8 weeks before last frost date, and can then be moved outdoors. To dry straw flowers, simply cut some from the garden and hang upside down in a dark, airy place for a few weeks.

Aug 6, 2014: Rhododendron cinnabarinum subsp. xanthocodon Concatenans Group

Rhododendron cinnabarinum subsp. xanthocodon Concatenans Group

A couple of months ago, I spotted a rhododendron while walking along Lower Asian Way in UBC Botanical Garden's David C. Lam Asian Garden. The contrast between the upper blue-tinged young leaves and the lower older yellow-hued leaves was striking. When I approached, I saw that it was named Rhododendron cinnabarinum subsp. xanthocodon Concatenans Group. This evergreen species' foliage has a pleasant aroma that I would describe as spicy or cinnamon-like. Maybe the epithet made me think of cinnamon, and despite seeming like it describes the smell, it actually refers to the cinnabar-red flowers of some of the other subspecies that were first introduced into cultivation from the Himalayas in 1849.

Earlier in the year, fleshy yellow flowers adorned this plant. Plants that are attributed to subspecies xanthocodon have lilac to mustard-yellow flowers. Unfortunately though, I didn't photograph it when it was in bloom. However, you can see what they looked like (and a selection of other Rhododendron taxa we have here at the Garden) in this thread on the UBC Botanical Garden Forums, with photographs taken by Wendy Cutler. Worth noting, as an aside, is that the nectar from this species is reputed to be the most poisonous of the entire genus.

Aug 5, 2014: Oxalis oregana

Oxalis oregana

Here's a photo of Oxalis oregana, or redwood sorrel. I took this photo in May, within the California coast redwood forest of Prairie Creek Redwoods State Park. This was during an ecology field course.

Oxalis oregana, of the Oxalidaceae, is native to coastal British Columbia, Washington, Oregon, and California. This perennial groundcover grows in dense carpets under the shaded canopy of redwood and Douglas-fir forests. Redwood sorrel is a species that prefers shade--photosynthesizing at light levels of 1/200th of full sunlight. When it is too bright, the three heart-shaped leaves fold downward until it is shady again.

Not seen in this photograph are the delicate, pink to white flowers with five petals. This species also contains oxalic acid, leaving the edible leaves with a sour and tangy taste. This hints at the genus name Oxalis coming from the Greek oxys, meaning "sour".

Aug 1, 2014: Gnetum gnemon

Gnetum gnemon

Today's photo is of Gnetum gnemon, of the Gnetaceae. This photo of the male strobili was uploaded to the Botany Photo of the Day Flickr Pool by Mike Bush (aka aviac@Flickr). Many thanks, Mike!

Gnetum gnemon (PDF) is an evergreen tree native to southeastern Asia and the western Pacific Islands. It grows from tropical lowland forests to lower montane forests, ranging in elevation from near sea level to 1700 meters. It prefers well-draining sites in areas that receive 3000 to 5000mm of mean annual rainfall.

Gnetum gnemon, commonly called melinjo, is used extensively in cuisine. In Malaysian-Indonesian cuisine the young leaves, strobili, and young and ripe fruit are used in cooked dishes. The seeds are consumed raw, boiled, roasted, or processed by pounding the kernels into cakes or crackers. In Malaysia it is common to see young leaves and shoots in seafood dishes. In Vanuatu, the leaves and male strobili are boiled and flavoured with coconut cream. In Fiji, young leaves are cooked in coconut milk and the fruits are also consumed. You may find the fruits to be used as a substitute for coffee in the Philippines. In Papua-New Guinea, the leaves and young cones accompany meat and are often served with a sauce made from the red pulp of Pandanus conoideus.

This species also has medicinal and practical uses. The sap has been used in traditional medicine to treat eye complications. The timber from the wood is utilized for beams for houses, tool handles, and box-making. The wood may also be made into paper or used for fuel. In Papua-New Guinea, the bast fibres (phloem fibre) under the outer bark are sometimes used for making cordage for string bags, bowstrings on musical instruments and fishing lines.

Jul 30, 2014: Peltigera gowardii

Today we have a photograph of Peltigera gowardii. Richard Droker (aka wanderflechten@Flickr) took this photo looking down into a stream, and later uploaded it to the Botany Photo of the Day Flickr Pool. Thanks, Richard!

A member of the Peltigeraceae, Peltigera gowardii is a lichenized ascomycete. The cyanobacterium Nostoc forms an indistinct algal layer throughout the medullary tissues. This species is sub-erect, with a foliose thallus. The thallus is black when wet, and slate grey to black and papery when dry.

Peltigera gowardii is widely distributed throughout the mountain ranges of northwestern North America. The range extends from central/northern California northward to Oregon, Washington, and British Columbia with disjunct populations in Idaho and southern Alaska. This species is associated with older forests and watersheds on shaded rocks, often 0-2cm above water level.

It was only recently that Peltigera gowardii was described as a species. Previously, it was considered to be Peltigera hydrothyria—the morphologically similar eastern North American counterpart of Peltigera gowardii. In a taxonomic revision published in 2011, researchers reviewed Peltigera hydrothyria across North America. In addition to a molecular phylogenetic analysis, they evaluated the biogeography, ecology, morphology and chemical composition of lichens from both sides of the continent. This was to determine if they were or were not conspecific (the same species). They found that the eastern and western populations differed allopatrically (occurring in separate non-overlapping locations), chemically (the eastern group contains the secondary compound methyl gyrophorate and the western group does not), and molecularly. They also found that within the western population there were two distinct sequence types. This left them with a case where morphological characters supported a single widely-separated species, chemical analysis supported two species, and molecular data supported three species (where two have identical chemistry and overlapping ranges).

After consideration, it was determined that chemistry, biogeography, and molecular data are all in agreement in rejecting the circumscription of Peltigera hydrothyria based on morphology. It was then decided that at least one new species should be described to accommodate the western populations, and Peltigera gowardii is now recognized as a distinct species circumscribing two phylogenetic entities. More research is needed to determine if Peltigera gowardii can be further divided taxonomically (see: Lendemer, J. O'Brien, H. (2011). How do you reconcile molecular and non-molecular datasets? A case study where new molecular data prompts a revision of Peltigera hydrothyria s.l. in North America and the recognition of two species. Opuscula Philolichenum. 9:99-110).

Jul 25, 2014: Geastrum triplex

Today we feature the fungus Geastrum triplex, commonly known as the saucered or collared earthstar. These images (image 1 | image 2) were taken recently at the State Botanical Garden of Georgia and uploaded to the Botany Photo of the Day Flickr Pool by Hugh Nourse (aka Hugh and Carol Nourse@Flickr). Thanks for sharing, Hugh!

Geastrum triplex, of the Geastraceae, is an earthstar fungus. The earthstars are comprised of the genera Geastrum, Astraeus, and Myriostoma. Earthstars are modified puffballs that have a thick outer skin that splits into star-like rays (Geastrum saccatum was featured on Botany Photo of the Day in 2011). The rays, after splitting, often curve to expose the spore case (inner skin) for spore dispersal. Some earthstars are hygroscopic, though, most geastrums (including Geastrum triplex) are not. After the rays split, the central region of Geastrum triplex often (not always) breaks loose to form a broad cup or saucer around the flattened spore case. The spore case of the saucered earthstar is not elevated on a stalk (like others in the genus), and holds powdery, brown spores that are round and warted.

Geastrum triplex is a saprobic (feeding on dead or decaying matter) fungus that is widely distributed across North America. It grows alone or in groups in forest humus, often under hardwood trees. This species (like all earthstars) is noted to be difficult to find when immature because individuals are inconspicuous, and often develop underground. If you do happen to find this fungus when it is young (white inside), it is considered edible according to Mushrooms Demystified by David Arora. When they are older (and easier to find), they are apparently often too tough and fibrous to eat.

Jul 21, 2014: Hoita strobilina

It's always a treat to feature a photograph from the late James Gaither (aka J.G. in S.F.@Flickr). Today we feature Hoita strobilina (image 1 | image 2), or Loma Prieta hoita, of the Fabaceae. These photographs were taken in Regional Parks Botanic Garden, in Tilden Regional Park in the Berkeley Hills in July of 2009, and uploaded to the Botany Photo of the Day Flickr Pool. Thanks again, James!

Hoita strobilina is a threatened, perennial herb endemic to California. It occurs naturally in chaparral or oak woodland on serpentine, or Franciscan-formation substrata. It descends into gravelly creek beds draining from the mountains into the Santa Clara Valley. This species went largely unnoticed (and without protection measures) until a comprehensive monograph was conducted. It is now listed as rare, threatened, or endangered in California and elsewhere by the California Native Plant Society. The CNPS also notes that this species is threatened by urbanization, and possibly by feral pigs and foot traffic.

Jul 18, 2014: Salicornia bigelovii

Salicornia bigelovii

Many thanks to Pete Veilleux (aka pete@eastbaywilds.com@Flickr) for this photo of Salicornia bigelovii! Pete took this photo of pickleweed (commonly known as annual glasswort, dwarf glasswort, dwarf saltwort, as well as sea asparagus) in Todos Santos, Baja California Sur, Mexico back in April, 2009 and uploaded it to the Botany Photo of the Day Flickr Pool.

Salicornia bigelovii, of the Amaranthaceae, is an annual halophyte. This succulent species has jointed stems that are initially green, age to yellowish-orange, and mature to dark red. Perfect flowers are sunken in cavities and are arranged in a three-flowered cymose pattern, with the middle flower being slightly elevated in comparison to the other two lateral flowers. The cymes are held in a terminal spike and later bear seeds that lack endosperm and contain a peripheral, bent embryo.

Pickleweed occurs on temperate, subtropical, and tropical coastlines of the New World. It ranges from coastal Nova Scotia, Canada, south to Florida and along the Gulf Coast to the Yucatan Peninsula to the Bahamas and West Indies. It also occurs along the Pacific coast in California, northern Baja California, and Sonora. Salicornia bigelovii tends to grow on saturated substrates of quartz sand, or sand and shell deposits and tolerates salinities up to 120 parts per thousand (to read more about how this species is able to grow in such saline environments, here is a link provided in a previous Botany Photo of the Day entry on Salicornia virginica and its parasite Cuscuta salina).

Salicornia bigelovii is a salt-tolerant terrestrial vascular plant with potential as a crop plant for arid, coastal, hyper-saline sites. It has been successfully cultivated, and can be irrigated with salt water. The seeds of this species contain 31% protein, 5-7% fibre, and 5-7% ash. The seeds also contain good-quality oil, and have up to 26-33% oil (exceeding oil seed levels of both cotton at 15-24%, and soybean at 17-21%). It is suggested that the seeds could be used for cooking oil, biofuels, and as supplements to poultry and fish diets. Each pickleweed plant can produce 250-640 seeds per plant, and when supplemental nitrogen was added to plots in a California salt marsh, seed production increased from 200000 seeds/m2 in unfertilized plots to 1 million seeds/m2. Some also note that the whole plant could be used for livestock forage, and as a biofilter for removing nutrients from saline aquaculture wastewater. Fresh and dried whole plants are also edible. Fresh shoots have been marketed in Europe and California as a garnish for salads, however the shoots only have a short shelf life of ~6 days (see: Falasca, S. Ulberich A. Acevedo, A. 2014. Identification of Argentinian saline drylands suitable for growing Salicornia bigelovii for bioenergy. International Journal of Hydrogen Energy. 39:8682-8689; Lonard, I. Judd, F., Stalter, R. 2012. The biological flora of coastal dunes and wetlands: Salicornia bigelovii J. Torrey. Journal of Coastal Research. 28(3):719-725).

Jul 16, 2014: Allium cristophii

Allium cristophii

A quick entry for the day about Allium cristophii, or the star of Persia. This photo was uploaded to the Botany Photo of the Day Flickr Pool back in May of this year by Christopher (aka c.young@Flickr). Thanks for sharing, Christopher!

Allium cristophii (subgenus Melanocrommyum), of the Amaryllidaceae, is a bulbous perennial native to Iran, Turkey, and central Asia. It is planted ornamentally for its large, spherical, purple flower heads of over 100 individual flowers that bloom in the spring. The flower heads of this species are noted to be amongst the largest produced by ornamental onions at 20-25cm in diameter.

The star of Persia is mentioned to be easily grown. Planting in rich, sandy to gritty soil in well-drained loams in full sun should do the trick. Apparently they do well in dry, sunny areas, particularly as over-moist soils may cause bulb rot. This species may colonize over time. If you want to control unwanted spread, deadhead the flowers before seed set.

Today I did want to write about Helianthus annuus, as this species was mentioned in the news yesterday. However, it has been featured on Botany Photo of the Day both last year and in 2007. To quickly summarize, it was highlighted in the news from Nature that this flower species bends to track the path of the sun, and researchers have found it is not only a response to light, but also to an internal clock. To see more, check out the article and accompanying video.

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