BPotD Archives being removed

Results tagged “written by tamara”

Feb 20, 2015: Merremia discoidesperma

Merremia discoidesperma

Returning to the exceptional seeds series, here is the fourth entry by Tamara Bonnemaison:

The species with the longest-recorded drift range in the world, Merremia discoidesperma, is the subject of today's entry. Susan Ford Collins (aka jungle mama@Flickr) provides this gorgeous photo of a Merremia discoidesperma seed that has been colonized by tiny corals on its long drift through the ocean from Mexico or Central America to Miami Beach.

Merremia discoidesperma or Mary's bean, is an uncommon woody liana found only in Mexico, Cuba, Guatemala, Costa Rica, and Hispaniola. Mary's bean is little known in its plant form--its real claim to fame is for its seed. In fact, the seeds of Merremia discoidesperma were known and described for many years before the plant. In 1605, the Flemish botanist Carolus Clusius published the first drawing and description of a Mary's bean seed, labeling it as a "stranded seed", but the species did not receive its first binomial name until 1889, when John Donnell Smith named it Ipomoea discoidesperma. Mary's bean seeds are a conspicuous but rare find on beaches far from their origin, and they have been kept as treasured keepsakes, passed from mother to daughter, by people who have never seen the plant. Aside from the novelty of finding a beautiful seed washed up on the beach, the seeds from the Mary's bean plant have a hilum in the form of a cross, giving them particular religious significance for some.

Drift seeds are not common. Of all the plant species found on our diverse and wonderful planet, only around 250 are specifically adapted to drifting at sea. Mary's bean is exceptional even within this small group, as its seeds remain buoyant for an unusually long time--up to three years. The limited distribution of the species makes it possible to track the distance that it has traveled. Mary's bean seeds that wash into the Caribbean and Atlantic can be found as far away as the Norwegian coast, carried a distance of 9500km by the Gulf Stream. Seeds that end up in the Pacific Drainage Region may travel even further, with records of Mary's bean seeds washing up in the Wotho Atoll in the Marshall Islands, about 11000km from their originating site. However, it is possible that seeds from other species have drifted further. For example, sea beans, or the seeds of Mucuna holtonii are likely to travel even further than Mary's bean seeds, but because Mucuna holtonii has a more extensive distribution than Merremia discoidesperma, it is impossible to know exactly the distance traveled.

In order to enter the "drift seed club", seeds must not only be able to float, but must be able to do so for a period of at least one month. There are a few approaches that seeds take in order to float: some have cavities within the seeds; others are made buoyant through a corky or light-weight fibrous layer; and still others are thin enough that they float on the water's surface. In the case of Mary's bean, a cavity at the centre of the embryo provides the buoyancy needed for the seed to cross oceans. Despite its ability to disperse seed across the world, Merremia discoidesperma can only be found in a very limited geographic area. This was a source of puzzlement to the researcher Charles R. Gunn, who speculated that insect attack keeps this species from establishing in seemingly suitable environments where its seeds routinely wash up.

Feb 18, 2015: Alsomitra macrocarpa

Alsomitra macrocarpa

Tamara Bonnemaison is again the author for her series. She writes:

The third species to make into the exceptional seeds series is Alsomitra macrocarpa. Scott Zona@Flickr photographed this amazing winged seed at the Bogor Botanical Garden in Indonesia. Scott posted this lovely text along with his photo (follow link to read his whole quote): "I was transfixed as I watched dozens of winged seeds of Alsomitra macrocarpa glide to the ground in broad, lazy spirals. The seeds spilled out from a fruit hanging on the liana climbing on one of the enormous old trees in the garden. All the principles of aerodynamics as they relate to seed dispersal were manifest in that one lovely moment."

In an article published by the Fairchild Tropical Botanic Garden, today's photographer Scott Zona describes wind dispersal in seeds. Although different plants use different strategies, explains Zona, all wind-dispersed species are aiming to maximize their time aloft, which directly increases their dispersal distance. Some species use parachutes or plumes to float along air currents. Others are so small and light that they become a part of the fluid movements of air. The third strategy is to develop wings, and no seed has wings that can rival those of Alsomitra macrocarpa, or mitra.

A member of the squash family, mitra is a long liana that grows up into the canopy of the forests of Java, Indonesia. It is quite famous for its 13cm wide, gliding seeds that have inspired a number of aircraft builders. The seeds of the mitra have the ability to remain stable during flight, despite having no moving parts to adjust to changes in air current or other disturbances. This characteristic was noticed by the aircraft developer Igo Etrich, who developed the Etrich Taube, one of the world's first gliders and the first military aircraft to be mass produced in Germany. The wings of the Taube provided excellent stability for the aircraft, making it well-suited to observational flights. The Alsomitra macrocarpa seeds in flight look like little aircraft--you can watch them soar over the Javan tree canopy in this short BBC video: Vine seeds become "giant gliders".

Feb 17, 2015: Cocos nucifera (dwarf cultivar)

Cocos nucifera

Adding the second in her series, Tamara Bonnemaison scribes:

We continue our series on extraordinary seeds with this image of Cocos nucifera, generously shared by Ahmad Fuad Morad@Flickr. The photo shows seedlings of an ambiguously-named "aromatic dwarf" cultivar of the coconut palm, taken in Sungai Pau, Malaysia. Thank you Ahmad!

The previous entry about extraordinary seeds featured Phoenix dactylifera, or the date, and today we discuss the coconut. I am tempted to turn this series into a cookie recipe--perhaps if I featured Triticum and Brassica napus (for canola oil) next, we could put together a tasty treat from those four ingredients! I have selected Cocos nucifera for this series as it has the second largest seed in the world, and it also has an unusual endosperm that provides us with both coconut water and coconut "meat". The prize for largest seed in the world goes to Lodoicea maldivica (a 2013 BPotD entry).

Like the previously featured date, the coconut fruit is a drupe, composed of a relatively thin exocarp (skin), and a dry, fibrous mesocarp that is about as different from the date's sweet flesh as possible. Below the mesocarp one finds the endocarp, the hard pit that surrounds the seed of all drupes. In coconuts, the smooth endocarp is polished and made into bowls, jewellery, and all manner of crafts. If you would like to make your own coconut endocarp bowl (you could call it a coconut shell bowl to whomever you give it to), here are some instructions. Before making a coconut bowl, it is recommended that you drain the coconut water by finding the coconut's soft "eye". Coconut endocarps have three eyes or germination pores, but only one of those is soft - the other two are often called the 'blind' eyes. Below the germination pores nests the single embryo, whose radicle will break through the soft eye when germinated.

The coconut's seed is well protected by its husk, and so its testa (seed coat) is very thin. Within the papery brown testa is the endosperm, the tissue that surrounds and provides nutrition to the developing embryo. In the coconut seed, the endosperm goes through a nuclear phase of development, during which it is present in liquid form. This "coconut water", has recently gained popularity as a nutrient-rich and refreshing drink, but I wonder if anyone would buy it were it labeled with its botanical descriptor: glass of nuclear coconut endosperm, anyone? As the embryo develops, the endosperm begins to form cell walls, and this cellular endosperm is deposited in layers against the testa, forming the coconut's "meat".

The white coconut meat is rich in fat, and can be eaten as is, or made into coconut milk and oil. In coconuts that have avoided being eaten or damaged, the germinated embryo will form an absorbing organ called a nursing foot, which swells into the cavity of the coconut and absorbs the nutritious endosperm over the period of about one year. These seedlings are still not quite safe--apparently the nursing foot is also called a coconut apple, and is quite delicious.

This article is focused on the coconut fruit and seed. If you would like to learn more about Cocos nucifera in general, read this great article by the The Private Naturalist - The Coconut Palm.

"If you could count the stars, then you could count all the ways the coconut tree serves us."--Phillipine proverb

Feb 16, 2015: Phoenix dactylifera

Phoenix dactylifera

Tamara Bonnemaison launches a BPotD series with today's entry. She writes:

We kick off a series about exceptional seeds with the story of a 2000 year old Phoenix dactylifera seed that was successfully germinated. Thank you to 3Point141@Flickr for submitting this lovely photo of a plant in the cultivated Medjool Group of Phoenix dactylifera. This photo was taken at Excalibur Fruit Trees Nursery in Florida, USA.

Phoenix dactylifera, or the "true" date palm, has played an important role for thousands of years of human history. In 1963, a stash of seeds "dating" (sorry, couldn't help myself) from AD 70 was discovered in Masada, a fortress in present-day Israel. In 2005, Sarah Sallon of the Hadassah Medical Organization managed to germinate just one of the ancient date seeds, and that seedling has now grown into a palm tree called "Methuselah". Date palms are dioecious, and it had been hoped that Methuselah would turn out to be female and produce fruit. Unfortunately, this date palm plant is now known to be male, and Sallon and her team will need to undertake careful breeding with modern date palms to produce females that are as close as possible to the ancient cultivated variety. Learn more about Masada and the discovery of these seeds from this National Geographic article: "Methuselah" Tree Grew From 2,000-Year-Old Seed.

The date palm is a 15-25m tall plant that is perhaps native to western India or southern Iraq, but a long history of use and cultivation has made it difficult for botanists to determine its exact place of origin. The fruit of Phoenix dactylifera is likely well known to all BPotD readers; this fruit was cultivated as a staple food and even to make date wine as early as 4000 BCE, and is still commonly eaten today (mmmmm, date squares). Other parts of the date palm may not be as sweet, but are equally useful. For example, palm hearts are used as a vegetable, the fibres can be woven to make a textile, the leaves are used to make mats, and the seeds produce a nutritious oil. For a more comprehensive list, view the Food and Agriculture Organization's Date Palm Products bulletin.

Although the date palm can be wind-pollinated, the standard practice in cultivation is to hand-pollinate the flowers The flowers are borne at the top of the tree and covered by a protective spathe that splits open when the flowers are mature. The fruit is a one-seeded drupe, which goes from green to yellow to reddish-brown as it ripens. This brings us to the seed. Date seeds are oblong, ventrally-grooved and have a small embryo. A hard endosperm made of cellulose surrounds the embryo, which is surrounded by the mesocarp (the fleshy, sweet part of the date) and finally the epicarp or exocarp (the date's skin). These are common features of the seeds of many fruits, and my search to uncover just what allowed Methuselah's seed to remain viable for two millennia revealed little.

Seed longevity is poorly understood by the scientific community, but is gaining more attention with the growing interest in (and need for) seed banks. A 2008 paper by Loïc Rajjou and Isabelle Debeaujon, Seed longevity: Survival and maintenance of high germination ability of dry seeds, sums up our current understanding of the different factors that affect seed longevity. Rajjou and Debeaujon report that seeds are able to protect themselves with their testa (seed coat), antioxidants, and by reducing their metabolic activity; seeds also have the ability to repair their DNA and decontaminate themselves. It is not clear which of the above qualities allowed the Phoenix dactylifera seeds found in Israel to remain viable for such an extraordinary long time, but it is likely that high levels of antioxidants present in date seeds contributed to this high longevity (date seeds are being studied for antioxidant qualities which could be used to improve human health and longevity). The date seeds also benefited from the dry, dark conditions present in Masada Fortress.

Science overload? Have a look at Shevaun Doherty's artistic exploration of the Methuselah date for an entirely different way of understanding Phoenix dactylifera.

Feb 5, 2015: Viburnum tinus subsp. rigidum

Another entry written by Tamara Bonnemaison today. She writes:

The late James Gaither (aka JG in SF@Flickr) captured these two stages of Viburnum tinus subsp. rigidum, first in flower and then in fruit, at the UC Berkeley Botanical Garden. We are so grateful for the amazing collection of botanical photography that James Gaither has left for all of us to enjoy -- please do visit his Flickr site.

Viburnums have been featured many times on Botany Photo of the Day, including Viburnum betulifolium, Viburnum rhytidophyllum, Viburnum lantanoides, and Viburnum × bodnantense. It is no wonder the staff at BPotD are fond of viburnums. The shrubs and small trees of this genus are native to the temperate Northern Hemisphere, and many are commonly used in the gardens and landscapes of British Columbia and around the temperate world. The viburnums are loved by gardeners for their showy and often scented flowers, bright berries, and fall colour. The genus is quite variable, and one of the few characteristics shared by all members is that the fruits are drupes (stone fruit). Another characteristic that applies to nearly all viburnums is that they are reluctant to self-pollinate, so multiple plants of the same species (ideally not of the same clonal stock) should be planted in order to get a good fruit set.

Viburnum tinus is an excellent garden ornamental. It has an upright, oval to rounded form, and its evergreen leaves grow right down to the edge of the ground, making it particularly useful as a screen or hedge. The common name for this species, laurustinus, comes from its lustrous, laurel-like dark green leaves, which are complemented by pink buds that open to white, slightly fragrant flowers in winter. These flowers mature to the stunning black, metallic fruits shown in today's second photo. Laurustinus is quite easy to grow, being adaptable to most soil types and tolerant of full sun, salt spray, shade, and drought. Viburnum tinus is native to southern Europe, but the subspecies rigidum hails from the Canary Islands. I could not find a habit photo of the subspecies, but a lovely photo of Viburnum tinus growing wild in Sardinia was photographed by Gino Cherchi: Viburnum tinus.

Laurustinus may have some medicinal qualities; I found some sources that discussed its potential as a treatment for menstrual cramps, but cannot validate its efficacy (the same sources also said the berries could be toxic, so please don't try this out!). The most enthusiastic source of medical information about the viburnum genus is the 9th Edition of the Journal of Materia Medica, published in the 19th century. This source raves of the compound viburnin that the "Eclectic Physician" used to treat an array of diseases. This substance was derived from the bark of the high cranberry (Viburnum opulus), but is potentially also found in other species of Viburnum. Much more recently, the author of the blog Naturally Dyeing has used laurustinus to dye fabric (read about her attempts).

Dec 10, 2014: Etlingera corneri

Etlingera corneri

BPotD work-learn student Tamara Bonnemaison authors today entry:

Thank you to 3Point141@Flickr for this excellent photo of Etlingera corneri taken at the Fairchild Tropical Botanical Garden in Florida, U.S.A. This image is one of a series of impressive ginger photos taken by 3Point141@Flickr; visit the ginger album to view the rest.

Etlingera corneri, also known as ka lo or rose of Siam, is a member of the ginger family that is native to southern Thailand and the northern region of the Malay Peninsula. There are about 70 members in Etlingera, and Etlingera corneri was only described in 2000 after John Mood and Halijah Ibrahim found that Etlingera venusta had been used to refer to two different species. The naming of rose of Siam has not been without controversy; C.K. Lim was studying this species at the same time as Mood and Ibrahim submitted their article to the Nordic Journal of Botany. Lim rapidly established a new journal and fast-tracked a publication in the attempt to be the first to describe what he called Etlingera terengganuensis. A subsequent article in the Nordic Journal of Botany, written by Kai Larsen (2000) defended Etlingera corneri as the correct name, which is the name that I have chosen to honour in this article.

Another Etlingera, the popular torch ginger or Etlingera elatior, was featured on Botany Photo of the Day in 2007. Torch ginger is cultivated in tropical climates as a garden ornamental, for use in flower arrangements, and as a food plant. Although not well known, rose of Siam is also a good candidate for many of the same uses. This species is said to produce more blooms than the other taxa of Etlingera, and the glossy red flowers are large, showy, and long-lasting. Like all members of the Zingiberaceae, rose of Siam has cells that contain essential oils, rendering the inner sheathes of the shoots tasty on their own or as a flavourful condiment.

After seeing the photo that accompanies this write-up, I was surprised to learn that rose of Siam is a perennial herb that grows to 3 or 4 meters. The photo shows the shorter, leafless stems that bear the inflorescence, and just barely shows the leaf-bearing stems which are found growing high above. The showy parts of the inflorescence are composed of two rows of sterile bracts that are rounded or truncate (Etlingera venusta has bracts that are tapered to a point) and that persist past infructescence, a quality that makes rose of Siam potentially even more desirable as a cut flower than torch ginger, whose bracts decay more quickly.

Dec 6, 2014: Saxifraga paniculata

Saxifraga paniculata

A photograph and written entry by Tamara Bonnemaison today. She scribes:

During a morning with frost a few weeks ago, the silvery-tipped leaves of this Saxifraga paniculata stood out among the many other beautiful specimens in UBC Botanical Garden's Alpine Garden. Daniel has been patiently teaching me to use the BPotD camera, and despite my best efforts, I was not quite able to capture the glow of the morning sun playing across the surface of the saxifrage's rosettes. This photo comes fairly close; for the rest, you'll need to use your imagination.

Saxifraga paniculata, also known as lime-encrusted saxifrage and white-alpine saxifrage, is a circumboreal species that is found in calcareous boreal, subalpine, and alpine habitats in North America, Europe, Scandinavia, Iceland, and Greenland. This species' common name is a result of lime-secreting pores on the leaf edges, which give the toothed leaves a silvery or 'encrusted' appearance. What I had at first thought to be the work of a particularly hard frost was actually the combination of frost and secreted lime, both of which contributed to making this plant literally glow against the shaded ground.

Encrusted saxifrage is a stoloniferous perennial that is extremely hardy. Its stiff, leathery leaves form 3cm tall rosettes that close as they become desiccated, with the outer leaves acting as an evaporative and solar shield for the younger leaves in the centre of the rosette. During times of extreme drought, these outer leaves dry out completely, but the plant itself is protected and survives. The species is also able to survive a short growing season and long periods of cold-induced photoinhibition (meaning that it is so cold that very little photosynthetic activity can occur). On top of having to survive extreme cold, drought, and insolation, Saxifraga paniculata must contend with an irregular supply of pollinators. However, it can both reproduce vegetatively through its stolons and self-pollinate.

The perfect flowers of lime-encrusted saxifrage are quite beautiful. I came across this species at the wrong time of year to capture the white, five petaled flowers, but thankfully these have been amply photographed by others. The Acta Plantorum website has many photos that show the curious purple-dotted white petals, as well as some images of lime-encrusted saxifrage growing in its alpine habitat.

Dec 3, 2014: Sophora tomentosa subsp. australis

Tamara Bonnemaison is the author of today's entry. She writes:

Today I was inspired by dustaway@Flickr's photographs of Sophora tomentosa subsp. australis (second image), taken at the Lismore Rainforest Botanic Garden in Australia. Thank you!

I had never heard of this species, and upon seeing the image of the plant in bloom, it felt very familiar - reminding me of other members of the Fabaceae such as one of my favourite species, silky lupine (Lupinus sericeus), and one of my least favourite, the locally-invasive Scottish broom (Cytisus scoparius). I then saw the photo of the fruit, and although it was obvious that these were leguminous, they were quite unlike anything that I had seen before.

The seedpods of Sophora tomentosa have resulted in the assignment of a colourful and descriptive common name: yellow necklacepod. Yellow necklacepod has 10-18 cm long pods that are strongly constricted between each of the 5-10 seeds. The indehiscent pods start out a light yellow-green, and mature to the husky brown shown in dustaway's otherworldly photo.

Sophora tomentosa subsp. australis is an uncommon shrub of seashores in the states of Queensland and New South Wales in Australia. This subspecies is of conservation concern, likely due to the limited range and coastal development. Its leaves are covered by grey to white hairs that give this species its other common name, silver bush, as well as its Latin species name tomentosa, meaning "covered with dense woolly hairs". Tomentose leaves are a common characteristic of coastal plant species, evolved to mitigate the heat and moisture stress common in such environments.

While researching this taxon, I learned of the work of the visual artist Sophie Munns. She has also seemingly been inspired by it. It's worth taking a look at her series of colourful and dynamic paintings of various types of seedpods.

Nov 28, 2014: Artemisia tridentata subsp. tridentata

Artemisia tridentata subsp. tridentata

Another entry from Tamara Bonnemaison today, who writes:

This Artemisia tridentata subsp. tridentata, or basin big sagebrush, was photographed by Cliff Hutson (aka The Marmot@Flickr) at the Rancho Santa Ana Botanic Garden in Claremont, California. I have taken many washed out, grey photos of fields of Artemisia, and thought Cliff did a particularly good job of highlighting the beauty of this plant against a dark backdrop. Thank you Cliff!

Artemisia tridentata, or big sagebrush, is a ubiquitous species that dominates landscapes of the Intermountain West of North America. Anyone who lives in this area likely has some kind of affinity with big sagebrush; I grew up in the South Okanagan of British Columbia, and can still close my eyes and remember the intense smell of sage and wet dust after a summer rain. Once, a close friend who invited her family over for Thanksgiving dinner found that the turkey was inedible. She later learned that the big sagebrush she had rubbed all over it was not the same type of sage called for by her recipe. Artemisia tridentata has the ability to elicit a personal and often visceral response from people, even those who would usually not give plants a second thought.

Artemisia tridentata subsp. tridentata is the most widespread of the 4 or 5 recognized subspecies of big sagebrush. The prolific Thomas Nuttall first described Artemisia tridentata in 1841, following collection of an Oregonian specimen obtained during the Wyeth Expedition of 1834-1837. Big sagebrush is a species of importance to many aboriginal peoples of North America, and is called kéwku by the Secwepemc people and ʔa•knuqǂuq̓unaʔqa by the Ktunaxa. The links above include sound-clips of the correct pronunciation for these names.

Big sagebrush is a pale grey evergreen shrub that reaches 0.5 to 3 meters in height. One property that maximizes its ability to access groundwater is a combination of a deep tap root and extensive fibrous root network. Also contributing to its tolerance of dry conditions, its small, silver-haired leaves ensure a minimum of moisture is lost in the hot arid climate favoured by the species. Artemisia tridentata improves conditions for surrounding plants, as the taproot brings water closer to the surface, and the above-ground parts of the plant create shade for grasses and herbs. Small herbaceous plants growing under a big sagebrush are often taller and denser than plants growing in the open. Big sagebrush is also of benefit to many animal species, such as the sage grouse and mule deer, and is host to many gall-forming insects, including Rhopalomyia medusa, which was featured in a previous BPotD entry.

Hugh Nelson Mozingo covers Artemisia tridentata extensively in his book, Shrubs of the Great Basin: a Natural History. In his chapter dedicated to big sagebrush, Mozingo puzzles over the disdain that cattle have for this species, despite the high nutrient value of its leaves (much higher than alfalfa, Medicago sativa). The author hypothesizes that cattle dislike the flavour of a group of volatile compounds found within the big sagebrush's leaves and that wild deer, who browse extensively on the species, compensate by "belching" the compounds as they chew. The inability (or at least unwillingness) of cattle to consume sagebrush has dramatically changed the Intermountain West landscape. In the past, bunchgrasses and forbs were much more common, but cattle have selectively consumed those plant types, and have left near monocultures of big sagebrush in their wake.

Nov 21, 2014: Apium graveolens var. rapaceum 'Ibis'

A short entry by work-learn student Tamara Bonnemaison today. She was also the photographer.

Last week I woke up to the first frost of the year, and decided it was the perfect time for a morning stroll through UBC Botanical Garden. Walking through the Food Garden, I was reminded of the feeling of surveying my small farm after a frost, feeling at once relieved that the busy season was over, and disappointed at the loss of income that a frost represented. Now that I am a student, I can walk through a garden and focus instead on the pattern of ice crystals kissing the edges of leaves, and wonder at the biology that allows some plants to withstand freezing while others succumb at the slightest dip in temperature. This celeriac, Apium graveolens var. rapaceum 'Ibis', looked like it was only gently touched by the frost, and the knobby stem will remain delicious for many cold months.

Celeriac, also called knob celery, is a type of celery grown primarily for its flavourful knobby hypocotyl (stem below seed leaves), leaves, and roots. It is cultivated in temperate vegetable gardens and farms around the world, but is most popular in Europe. Celeriac requires a long growing season, and the taste of its gnarly-looking stem sweetens after a frost, making it perfect for wintery dishes such as these recipes for remoulade and soup. I haven't yet tried these, but they look particularly delicious.

Celeriac has a number of the qualities that allow it to survive and stay tasty in cold weather. A report by the FAO discusses frost physiology in common vegetables, and Apium gravoeolens var. rapaceum exhibits a number of the traits that the FAO lists as ways that plant species tolerate cold temperatures. For example, the large, fleshy stem has a high heat capacity, preserving the day's heat well into the night. Also, the entire plant is able to gradually "harden" by increasing concentrations of solutes such as sugar to lower the freezing temperature of its tissues. All that is to say that it is very convenient that starchy root vegetables such as celeriac achieve their peak late in the season, just in time for the thick soups and comfort foods that feel so good to eat in the winter.

Nov 18, 2014: Dicranum scoparium

Dicranum scoparium

...and another entry by Tamara Bonnemaison today:

Thank you to to Robert Klips (aka aka Orthotrichum@Flickr) for posting a lovely shot of broom moss in the snow (with a little fern moss, Thuidium delicatulum, also making in appearance). Robert took this photo last February in Delaware County, Ohio, USA. For a close-up image of Dicranum scoparium with sporophytes at different stages of maturity, see this image by Phil Pullen.

The widely-distributed Dicranum scoparium is found on moist and sunny rocks, cliff edges and logs across North America, Europe, Asia, Australia and New Zealand. The 2-8cm tall stems form soft turfs. The hair-like leaves have a "swept" appearance, giving this species its common name.

Robin Wall Kimmerer inspired me to write about this species. Kimmerer has written a very entertaining book, Gathering Moss, A Natural and Cultural History of Mosses. Moss reproduction is a fascinating subject in general (well, at least if you are a plant geek like me - but as you are reading this, I suspect you are!) and I found the way that Kimmerer describes Dicranum reproduction particularly colourful. Moss reproduction is often hit and miss, and in the case of Dicranum scoparium, the female of the genus has taken control of the process in order to ensure a higher chance of success. Broom moss spores have no gender, and the ultimate sex depends on where the spore lands in relation to other female members of its species. If the spore lands away from the nearest turf of broom moss, it will develop into a female. Those spores that land on an established female develop into something called a "dwarf male".

Dwarf males grow to only a few millimeters, and to the visible eye appear as nothing more than a miniscule cluster of leaves, growing as an epiphyte on a full-sized female. There are many advantages to this arrangement. By commanding the least amount of space and resources possible, dwarf males do not compete with the females, who need moisture, sunlight, and nutrition in order to support the growth of their sporophytes. Even more importantly, dwarf males are placed as close to the female gametophyte as possible, greatly reducing the amount of ground that a swimming sperm needs to cover in order to be successful. This reproductive tactic is quite effective, with higher rates of fertilization occurring on the females hosting the largest numbers of dwarf males.

Kimmerer wrote that a hormone emitted by female Dicranum scoparium causes the males of the species to grow as dwarves, but a literature review by Pichonet and Gradstein (2012) (9 years after Kimmerer's book was published) did not find conclusive evidence that dwarf males were caused by chemical factors. Instead, Pichonet and Gradstein conclude that "genetic factors, environmental factors, and unfavourable nutrient conditions" can all result in dwarf males.

Nov 13, 2014: Mucuna holtonii

Tamara Bonnemaison wrote today's entry:

Today I have selected two photos taken by Reinaldo Aguilar (aka Reinaldo Aguilar@Flickr), one of the authors of the Vascular Plants of the Osa Peninsula, Costa Rica. Reinaldo's images show an otherworldly Mucuna holtonii taken at Charcos, Puntarenas, Costa Rica (other image and complete Mucuna album). I am really excited to write about this species; thank you Reinaldo for providing the photos!

I was inspired to learn more about Mucuna holtonii after reading a National Geographic article about plants that "speak" to bats. This beautifully-written article, "Call of the Bloom", follows the work of Dr. Ralph Simon through his discovery that many bat-pollinated tropical plants have special features that reflect sonar in particular ways, allowing bats to quickly find them in the dark and over large distances. Mucuna holtonii was one of the first species examined for its capacity to guide echo-locating bats to its nectar-rich flowers. This neotropical vine grows high in jungle canopies of central America, and dangles its flower clusters on long stems, isolating the night-blooming flowers from surrounding vegetation. This on its own provides ideal conditions for bats to locate the flower and access its nectar, but the species makes this process even easier through an adaptation that bounces back the bat's sonar at a high amplitude.

Like many other members of the pea family, the flowers of Mucuna holtonii have a banner, keel, and wings formed by 5 irregular petals. In Mucuna holtonii, the banner (also called the vexillum or standard) is waxy, concave and is raised like a flag (or should I say a satellite dish) as the flower bud opens. Today's photo shows this quite clearly, and it is easy to imagine sound bouncing off of the banner's surface in a clear and concentrated manner. The researchers Dagmar and Otto von Helversen found that the presence of these banners made a remarkable difference in bat visitation rates. In their study, 88% of virgin flowers were visited by bats, but when the researchers removed the banners, that number dropped to only 21%. Mucuna holtonii is but one of many plant species that makes itself more visible to echolocating pollinators. In an effort to find other plants with acoustic capabilities, Dr. Ralph Simon has started the Flower Echo Project, and has so far tested the echoes of over 65 flower species.

Flower-bat communication is only one of the many interesting features of Mucuna holtonii. Although I did not come across any common names for this species, the seeds of many Macuna species are referred to as "sea beans" because they often float down rivers and into the ocean (they are also called hamburger beans for their appearance). Washed up on far-away shores, the beautiful black seeds are often polished and strung to form necklaces and bracelets. Kew Garden's Economic Botany Collection is home to one such bracelet, made of a combination of Mucuna holtonii seeds and the smaller seeds of three other species.

Nov 5, 2014: Celastrus scandens

Celastrus scandens

Botany Photo of the Day Work-Learn student Tamara Bonnemaison contributes both the photography and the written entry today. She scribes:

At this time of year, the winter rains begin to hit Vancouver, and our local world recedes into tones of grey and misty green. Unless, of course, one happens to be strolling through UBC Botanical Garden's Carolinian Forest. Here, the rich yellows and reds one expects to see in eastern North America instead brighten our soggy, West Coast souls. This Celastrus scandens caught my attention with its bright fruit, and I am pleased to finally have taken a photo worthy of sharing with you, the fine readers of Botany Photo of the Day.

Celastrus scandens is a fast-growing woody vine native to central and eastern North America. It was given the common name of American bittersweet by European colonists who thought it resembled the unrelated bittersweet of their homeland, Solanum dulcamara. American bittersweet can be found in many habitats, including dune thickets, roadsides, and forests, and will grow to over 10 meters when given access to a climbing structure. In the garden, it can be used as a sprawling shrub to quickly cover hillsides or unsightly rip-rap, or can be grown on a trellis or fence. The plant photographed was wisely planted along a chain-link fence at the far edge of the Botanical Garden<, where it will soon hide this necessary but uninspiring structure.

The fruit of this species are particularly interesting. The three-valved capsules enclose a fleshy aril (an outgrowth from the funiculus, or attachment point of the seed), and burst open when the seed is ripe. I look forward to seeing this in action as the autumn progresses, but for now I had to make do with the many photos of this phenomenon available online, including one at the University of Michigan's "Climbers" web site. The bright red aril covers the seeds, and serves as further enticement for the birds who aid dispersal. The fruit is toxic to humans, and was used by the Cherokee to make poison.

The other visually-arresting aspect of this species is its stem. Having no tendrils, American bittersweet relies on twining of the stem apex for its ability to climb. I was not able to take a satisfactory photo of the twining woody stems, but I found them to be quite beautiful. Illustrative photos of the twining stems are available from Prairie Moon Nursery. The stem usually twines dextrally (left to right), and before photographing this plant, I had never considered that plants might have an equivalent to human left and right-handedness. In an attempt to understand why plants twine in one direction over the other, Edwards, Moles and Franks (2007) carried out a study that concluded that twining direction could not be explained by plants tracking the sun across the sky. The same study also concluded that the Coriolis effect was also not responsible for twining direction (on a completely unrelated side-note, the Coriolis effect also does not explain the direction that water drains in your sink). Edwards et. al's full paper, "The Global Trend in Plant Twining Direction", is available online. Now that we have an idea about what doesn't determine a plant's chirality, are there any sources that can explain what does? The best that I could find was the 2011 publication of Burnham and Revilla-Minaya, Phylogenetic Influence on Twining Chirality in Lianas from Amazonian Peru. This article gives the somewhat unsatisfying answer that "genetic, developmental, and physiologic perspectives" are required to understand why a plant may twist to the left or to the right.

Oct 31, 2014: Pontederia cordata

Tamara Bonnemaison writes today's entry, which features a representative of a family never previously highlighted on Botany Photo of the Day, the Pontederiaceae:

Today, regular BPotD contributor 3Point141 (3Point141@Flickr) shares his striking photo of Pontederia cordata, taken on the shoreline of Turkey Lake, Orlando, Florida, USA. Rusty Clark ((Rusty Clark@Flickr) also contributed her image of the species in flower. Thank you to both contributors!

Pontederia cordata, or pickerelweed, is a rhizomatous, emergent perennial that grows in wetlands from Argentina north to eastern Canada. It typically has lance-shaped leaves with rounded lobes, but the leaf shape in particular is quite variable and has led to the naming of several now-synonymized varieties. From June through November in eastern North America, pickerelweed sends up a large spike displaying hundreds of light blue flowers. This species grows prolifically and forms dense stands that, when blooming, are stunning in the wild and in garden ponds. To get an idea of how impressive a stand of pickerelweed in bloom can be, have a look at the fourth image shown on Dr. Spencer Barret's lab's site on floral displays.

Pickerelweed is common, is adapted to a wide range of wetland conditions, and grows rapidly and aggressively - traits that make the species useful in constructed wetlands in North America. Collins, Sharitz and Coughlin's (2005) study, titled "Elemental Composition of Native Wetland Plants in Constructed Mesocosm Treatment Wetlands" examines the beneficial role that Pontederia cordata can play in treating runoff from coal-fired power plants. Power plant runoff is both high in heavy metals and acidity, and the species selected for constructed wetlands treating this runoff must be able to survive such difficult conditions. Collins et al. found that Pontederia coradata was able to establish in shallow wetlands receiving acidic and polluted runoff, and was successful in taking up a moderate amount of heavy metals. Pickerelweed and the rush species, Juncus effusus, were particularly effective in accumulating iron and aluminum. Constructed wetlands can be used to treat water contaminated by many sources, and Pontederia cordata is being examined as one of an assemblage of plants that can be used to remove organic solvents, phosphorus, and other contaminants.

The characteristics that make pickerelweed useful in North American wetlands urge caution in other parts of the world. The species' aggressive nature has allowed it to become invasive in some countries, including Kenya. It has naturalized, though is not recognized as invasive, in areas of Europe, Australia and western North America.

Oct 23, 2014: Schinus molle

Botany Photo of the Day work-learn student Tamara Bonnemaison writes today's entry:

As a child, I spent many winters traveling through central Mexico with my parents, who were enamoured with the stark landscapes of the southern Chihuahuan Desert. One of our favourite camping spots, deep in the state of San Luis Potosi, was in an abandoned homestead, complete with the crumbling walls of an old adobe house and a thriving coral made of planted nopal (likely Opuntia ficus-indica). Next to the ruins of the house was one singular, fragrant tree, the only plant larger than a shrub as far as the eye could see. This tree, which the locals called a pirul, was a young child's dream. It's long, drooping branches made a green and cool oasis around the tree's trunk, and the pirul's fruit were nearly always to be found; clusters of tiny, glistening, pink and purple pearls that I used as "food" for my dolls drooped plentifully from the tree's branches. When crushed, the fruit and leaves left a strong, peppery scent that has stayed with me into my adult life. Seeing Gabriella Ruellan's (aka Gabriella F. Ruellan@Flickr) images of Schinus molle brought back a flood of wonderful memories of my childhood, and allowed me to finally connect the magical tree of my memory to its botanical name. Thanks Gabriella for sharing these photos.

Unknown to my childhood self, Schinus molle, or Peruvian pepper tree, is not native to central Mexico, and instead comes from the Peruvian Andes and northern South America. The seeds can be used as a replacement for the true pink peppercorns of the Piperaceae (the pepper family). During the 16th century, explorers and traders were quick to recognize the value of Schinus molle as a spice and rapidly spread the species around the globe. This hardy, drought-tolerant and beautiful species has become naturalized and even invasive in many parts of the world. It has become a serious problem in warm, arid areas including parts of South Africa, Australia, and the USA. It saddens me to think that it is inadvisable to plant Peruvian pepper tree anywhere outside of its native range.

Gabriella's photo shows bore holes in the fruit of Schinus molle. In the comments along with her image posting on Flickr, Gabriella hypothesizes that insects eating the seeds help keep this species in check in its native range. Peruvian pepper tree has been used and investigated for its insecticidal and insect repellant qualities, but it seems the insects that damaged the seeds in Gabriella's photo have not read those studies! While trying to investigate the insect that caused the damage shown in the photo, I learned that the peppertree psyllid, Calophya rubra, feeds on the tree's leaves, causing pits and leaf curls. Also, the omnivorous looper caterpillar, Sabulodes aegrotata and many scales are considered Peruvian pepper tree pests. It is not altogether surprising that I could not find an example of a borer that favours Schinus molle, given that I am entirely unfamiliar with the insects of Latin America. If any BPotD readers can shed some light on this subject, please share!

Oct 8, 2014: Clivia caulescens and Clivia miniata

Today's entry was written by Tamara, who scribes:

For this BPotD entry, I chose to compare two species of Clivia in order to highlight how one species in a group has evolved to use a different set of pollinators. Thank you to the late James Gaither (aka J.G. in S.F.@Flickr) for his photo of Clivia caulescens taken at the San Francisco Botanical Garden, and to Priscilla Burcher (Priscilla Burcher@Flickr) for her image of Clivia miniata taken at the Walter Sisulu National Botanical Garden in South Africa.

Clivias are endemic to South Africa and Swaziland. These yellow, orange, or red-flowering plants have been popular ornamental species in Western gardens since they were first collected by the British explorers William Burchell and John Bowie in the early 19th century. Clivias have long, dark-green strap-shaped leaves and are adapted to the low-light conditions of the forest floor. They have been extensively bred for ornamental qualities, and even have a global fan base (check out the Global Clivia Enthusiast Forum if you also share this passion). Clivia miniata is the most-cultivated of the genus, commonly called Natal lily or bush lily. It reaches a height of about 45 cm, and in its native habitat grows in well-drained, humus-rich soil of forest floors or, rarely, in the fork of a tree. Clivia caulescens is rarely cultivated. This species has an unusual stem for a Clivia, which reaches to 90cm in height with aerial roots along its length.

Natal lily is the only Clivia that is pollinated by butterflies, while Clivia caulescens, like all other species of Clivia, is pollinated by sunbirds. The botanists Ian Kiepiel and Steven D. Johnson, in the 2013 article Shift from Bird to Butterfly Pollination in Clivia assert that the ancestor of Natal lily was a sunbird-pollinated species like the other members of the genus. In the evolution of Clivia miniata, a transition to butterfly pollination occurred. One of the most pronounced shifts found by Kiepel and Johnson was that the flowers went from the pendulous, tubular flowers exemplified by today's image of Clivia caulescens to the upright, trumpet-shaped flowers of Clivia miniata. This change is best explained by examining the pollinating methods of sunbirds compared to butterflies. Sunbirds desire a perch while consuming their nectar, and the drooping flowers of Clivia caulescens allow these birds to perch on the flower stem and probe upwards for the nectar. Upright flowers, on the other hand, are nearly impossible for these birds to reach when perched on the stem. Rather than a perch, butterflies need a landing pad, which the upward-facing flowers of Clivia miniata provide. Upwards-facing flowers also allow the species to take advantage of butterflies that brush past as they explore and claim territory, collecting pollen on their wings and dispersing it onto the upright stamens. Kiepel and Johnson point out that these flower forms are similar to those found in other genera pollinated by either sunbirds or butterflies, respectively.

Other differences in flower physiology include lower pollen production and greater scent in Natal lily than in other members of the genus; birds require a greater amount of pollen than butterflies do, and rely much less on their sense of smell. The characteristics that did not change when the species shifted its pollination strategy are as interesting as those that did. Flower colour - a vibrant orange-red possessing a high UV reflectance, is the same for the sunbird and butterfly-pollinated clivias. Sunbirds and butterflies both have UV receptors, and are likely to be able to perceive the clivias in a very similar fashion. It is likely that this similarity in visual perception is one of the factors that made the change in pollinators possible. In case you want to know what a Clivia miniata flower looks like to a sunbird or butterfly, see Dr. Klaus Schmitt's image on the Photography of the Invisible World site.

Sep 30, 2014: Aloe arborescens

Tamara shares her second entry with us today. She writes:

The photographs today show Aloe arborescens in two native habitats in Mozambique. Thank you to Ton Rulkens (aka tonrulkens@Flickr), a long-time BPotD contributor, who shared these images of Aloe arborescens growing in the wild (image 1 | image 2).

This stunning branching aloe has an extensive range. It is also one of the most widely cultivated aloes in the world. Aloe arborescens is distributed natively throughout the southeastern part of Africa, including South Africa, Malawi, Mozambique, and Zimbabwe. Its natural habitats are rocky outcrops and ridges, but this succulent is adapted to many growing conditions and can be found from coastal elevations to mountaintops. Its common names include krantz aloe and candelabra aloe.

Aloe arborescens is a particularly large aloe, reaching a height of 2-3m (arborescens means "tree-forming" in Latin). The tall, sprawling branches are topped with a rosette of spiked, fleshy leaves, and from these rosettes grow showy scarlet racemes that are frequented by bees, butterflies, and sunbirds of southeastern Africa. Like the popular Aloe vera, Aloe arborescens has a variety of traditional and medicinal uses. A 2009 literature review published in Economic Botany found 47 documented uses of krantz aloe; these include healing wounds, improving circulation, improving food as an additive, and healing through antibacterial properties.

One of the most interesting cultural applications of Aloe arborescens is its use in traditional southern African kraals, or livestock enclosures. These are made by densely planting this species to form a corral. Krantz aloe has a few characteristics that make it highly desirable for such a use. Firstly, this aloe grows easily from cuttings, so establishing a new kraal takes little more than placing slightly dried leaf cuttings into the ground. Secondly, pruning of the branches initiates vigorous regrowth, so any leaves that are damaged by livestock are quickly replenished. Finally, the height and density of Aloe arborescens ensures that livestock remain in their pens. Surprisingly, long-abandoned kraals remain in the landscape for decades (or even a century!) because of Aloe arborescens persistence. Living aloe fences have been adapted for modern use as fire breaks in arid parts of the USA, Australia, and the Mediterranean. An informative article (via the web site restoration.me) about constructing such fire breaks compares krantz aloe fences to "a wall of water"; even if you don't have the time to read the entire article, make sure to take a quick peek at this incredible image of one such wall in full bloom.

Sep 26, 2014: Fascicularia bicolor

Fascicularia bicolor

We have a new author today. Tamara Bonnemaison joins us as one of two Botany Photo of the Day Work-Learn students from now until the end of April. For her first entry, Tamara writes:

Thank you to Christopher Young (aka c.young@Flickr), who shared this beautiful photo of Fascicularia bicolor via the Botany Photo of the Day Flickr Pool.

Fascicularia bicolor, or sun bromeliad, is a bromeliad endemic to Chile. Its genus name, Fascicularia, means "clustered together in bundles". This aptly describes the growth habit of this species, which forms mounds of rosettes growing to about 60cm tall. Zizka and Nelson (1997) report that the plant produces edible fruit, but I could not find a description of the fruit or its flavour.

Sun bromeliad is a good example to illustrate the morphological and ecological plasticity of the Bromeliaceae. There are two subspecies of Fascicularia bicolor, with each evolved for very different conditions found on Chile's interior rainforests and coast. Subspecies canaliculata usually grows as an epiphyte in Chile's Valdivian temperate rainforests. This subspecies has leaves with channeled adaxial (upper) surfaces and non-succulent bases, presumably to remove excess water quickly with no need for additional water storage. The other subspecies, bicolor, is saxicolous, meaning it grows in rocky ground. It is generally found in open habitat along Chile's coast. Fascicularia bicolor subsp. bicolor has leaves with a succulent base (to store water) and a flat surface.

I have walked past plants of this species many times at UBC Botanical Garden, and it wasn't until this September that it captured my attention. In the autumn, the inner leaves of Fascicularia bicolor become deep red and a rosette of contrasting blue flowers is revealed. Each rosette will flower only once; although the flowers are short-lived, the fiery leaves add a splash of colour to the garden all winter long. It is no surprise that a previous BPotD entry featuring this species in brief also had a photo taken over the fall/winter. The unusual coloring of Fascicularia bicolor, along with its relative ease of growth, make it popular with gardeners. Fascicularia bicolor subsp. bicolor may well be the hardiest bromeliad in the world, and will grow in full sun to part shade, provided that it is grown in a coarse, well-drained soil.

Despite its beauty, gardeners should beware! The leaves have hooked teeth that make short work of all but the hardiest of work gloves, and it is well worth the forethought to ensure that Fascicularia bicolor is planted in a location where it will need the least amount of handling possible; avoid planting under trees, as pulling fallen leaves out of sun bromeliad's rosette is a dangerous proposition. Needless to say, these hooked teeth are useful in protecting the plant from llamas in its native habitat.

Botany resource link (added by Daniel): New mushroom species discovered in London grocery store (CBC) is an article sent along by a UBC colleague, Dr. David Brownstein (thanks!). The story shows how DNA barcoding has helped mycologists from Royal Botanic Gardens, Kew discover scientificlly unknown porcini mushroom species in commercially-sold products. See the journal article as well: What's for dinner? Undescribed species of porcini in a commercial packet.


a place of mind, The University of British Columbia

UBC Botanical Garden and Centre for Plant Research
6804 SW Marine Drive, Vancouver, B.C., V6T 1Z4
Tel: 604.822.3928
Fax: 604.822.2016 Email: garden.info@ubc.ca

Emergency Procedures | Accessibility | Contact UBC | © Copyright The University of British Columbia