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Botany Photo of the Day
In science, beauty. In beauty, science. Daily.

Mar 27, 2015: Datura wrightii

Datura wrightii

BPotD Work-Learn student Tamara Bonnemaison writes:

I have been ogling the photos that Sandy Steinman (aka Sandy Steinman@Flickr) has recently posted to the Botany Photo of the Day Flickr Pool. I was sure that one of my predecessors would have already featured Datura wrightii, and was pleased to see that I am the first to write about this fascinating species on BPotD. Thank you Sandy, for this photo, and for all of the images that are making me yearn to hike in Joshua Tree National Park. Keep them coming!

Datura wrightii, also known as sacred datura or jimsonweed, is a representative of a group of plants that mean many things to many different people. Fans of Carlos Castaneda will know of this genus from Castaneda's hallucinatory accounts of his journey through the teachings of shamanism. Ethnobotanists will know of the traditional uses of Datura spp.--that a number of species were used by people of every continent (except Antarctica) to perform religious rituals, poison enemies, and treat the ill. Gardeners will know Datura wrightii as a deer-resistant species with exceptionally large and sweet-smelling white trumpet flowers that bloom at night. ER doctors who have had to treat overdosing experimenters will be familiar with the toxic effects of this genus. Sandy's photo beautifully captures the spiritual, aesthetic, and even dangerous characteristics of this species.

Another group that has investigated Datura, and specifically Datura wrightii, are entomologists and insect ecologists. One particular area of interest for this group is the way that Datura wrightii's trichome dimorphism affects insect herbivory. Some jimsonweed plants feel velvety, because they have short, non-glandular trichomes (which are fine outgrowths or appendages on the plant, in this case hairs). Others feel sticky, as they have glandular trichomes that secrete acyl sugars, thus providing resistance to herbivorous insects. In a 2005 article published in Ecology, Daniel Hare and James Smith compared herbivory and seed production of Datura wrightii plants expressing either the "sticky trichomes" or the "velvety trichomes" trait. Hare and Smith conclude that producing glandular trichomes reduces seed production in the plant's first year, and that the herbivory resistance conferred by the glandular secretions never fully compensates for this initial setback. Although the glandular trichome gene is dominant, under the study conditions examined by Hare and Smith, it did not confer an overall evolutionary advantage.

One of the most studied aspects of Datura wrightii is this species' relationship to the hawk moth (Manduca sexta). Adult hawk moths pollinate datura flowers, but also lay their eggs on the plants. The hatched larvae then consume datura leaves. This mutualistic yet also antagonistic relationship has interested many an entomologist (for more details, consult Bronstein et al's 2009 article, Reproductive biology of Datura wrightii: The Benefits of A Herbivorous Pollinator (PDF)). A particularly amusing facet of this relationship is that some people have noticed that hawk moths become intoxicated after wallowing in sacred datura pollen. Rather than quickly visiting one flower and moving onto the next, some hawk moths arrive before the flower opens, and once allowed inside, will submerse themselves deep inside the corolla, beating their wings frantically until completely covered in pollen. It appears that datura's alkaloids affect moths and humans alike. Learn more about these "jimsonweed junkies" via the nonist.

Mar 26, 2015: Amorphophallus konjac

Another entry from Tamara Bonnemaison today, who writes:

I can always count on frequent contributor to the Botany Photo of the Day Flickr Pool, Bruce Brethauer, for an interesting photo. Bruce (aka Glochidman@Flickr) has intrigued me with this shot of an Amorphophallus konjac inflorescence. Thank you for posting, Bruce! I also found a detailed botanical drawing on Wikimedia Commons. The artist, W. Fitch, composed the illustration in 1875.

W. Fitch's drawing of Amorphophallus konjac, also known as devil's tongue and voodoo lily, clearly details some properties of this species. For example, two versions of the entire plant are drawn. In the centre, Fitch shows a compound leaf growing from an unearthed tuber. On the left, Fitch shows the plant as it might look while growing in the ground and flowering. Fitch was obliged to show the plant at leafing stage and inflorescence stage separately since both do not occur at once; the impressive spathe and spadix emerge in late winter, and the single leaf will not emerge until well after the inflorescence has died back. Also, the artist has accurately depicted the roots coming from the top of the tuber--providing needed support for the top-heavy inflorescence--and has included a small tuber emerging from the larger one. Over the growing season, a new, larger tuber is formed, which replaces the older tuber. As the tubers grow larger, so do the leaves and inflorescences. A mature voodoo lily can be nearly two metres high, and the spathe alone can measure about one metre, with the spadix growing even longer.

One thing that cannot be shown in a botanical drawing or photograph is the scent. The voodoo lily emits the scent of decaying flesh in an attempt to attract its natural pollinators, carrion flies (Calliphoridae spp.). While researching this species, I came across many gardening posts discussing just how terribly, awfully, horribly bad the smell of Amorphophallus konjac is. Most, but not all, thought it was worth growing anyway. If you would like to try growing this unusual species, the Wisconsin Master Gardener Program has this information sheet on Amorphophallus konjac growth and care (PDF).

Despite the terrible smell of its inflorescence, the corm of the voodoo lily is used to make a popular food in Japan known as konnyaku (yam cake). The corms, which can reac6h the size of a large grapefruit, are cultivated and made into flour, jelly, or a vegan version of gelatin. Konnyaku can also be made into a type of noodle called shirataki. I have not tasted konnyaku, but am tempted to try out this recipe.

Mar 25, 2015: Cortinarius ceskae

Cortinarius ceskae

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

A newly discovered fungus species, Cortinarius ceskae is highlighted in today's BPotD. The species is named in honour of its discoverers, local mycological experts Oluna and Adolf Ceska. Oluna and Adolf collected this species as part of a decade-old macro-fungi survey of Observatory Hill in Victoria, British Columbia, Canada. So far, the species has not been found on any other site. Thank you for sharing this exciting discovery (and photograph) with us, Oluna and Adolf!

Oluna Ceska, with the assistance of her plant ecologist husband, Adolf, has been observing and collecting fungi from Observatory Hill since 2004, and has made over 300 collection visits to the site. From these visits, Oluna has collected records of well over one thousand species of fungi from a less than 75ha (<185 acres) area. Last year, Oluna and Adolf donated 3312 dried specimens to the Beaty Biodiversity Museum, and over the last decade the Ceskas have been responsible for filling one quarter of the the Museum's 26771 specimens of fungi. The specimens collected by the Ceskas have resulted in many new species records for British Columbia, and also a number of newly described species, such as Cortinarius ceskae, which was published in the Index Fungorum in 2014.

Cortinarius ceskae is found in coniferous forest and produces mushrooms in autumn. The Index Fungorum (PDF) describes it as follows:

"Pileus 20-30mm, at first conical, later almost plane, often with an acute umbo, reddish to rusty brown with an olive tone. Lamellae moderately spaced, cinnamon brown when old. Stipe 30-50mm long, 4-5mm thick at apex, cylindrical, fibrillose-rusty fibrils over yellowish background, base of the stipe yellow, at least when young. Context ochre. Odor in lamellae radish-like. UV fluorescence: pileus bright yellow on drying, lamellae bright yellow but patchy, stipe bright yellow, flesh in stipe pale yellow."

Daniel adds: Adolf has run the botanical email newsletter, Botanical Electronic News, for well over twenty years. I remember it being the one major thing that kept me in touch with the botanical world in the gap between the time when I finished university and later started at the Garden. If you are interested in botanical happenings (in particularly western North America), subscribe now and your first BEN will likely be the annual April 1st special edition.

Mar 23, 2015: Zaluzianskya ovata

Zaluzianskya ovata

The lead writer on today's entry is Eric La Fountaine, who also shared the photograph (and grows the plant). Tamara Bonnemaison made a few edits and adds a paragraph at the end. Eric, who is the collections technician here at UBC Botanical Garden, writes:

This delightful little plant has been producing this dramatic colour show for me each spring for four years now. I grew it from seed received as Zaluzianskya ovata. I was expecting the typical white-flowered form that I had grown previously--a form that had never survived the winter for me. I was thrilled with the bright orange-eyed flowers when they appeared. I did not expect the plants to thrive, but they have done well. In addition to their striking colouration, the flowers emit a wonderful perfume after sundown (a common name for the genus is night phlox), and bloom for several weeks in spring.

Zaluzianskya is endemic to southern Africa, with most species confined to South Africa. Although the African Plants Database lists ~93 taxa in the genus (Mabberley suggests 57 species in the genus), only a few are found in cultivation. Even those few are not well known. This taxon is offered for sale at various nurseries, either as Zaluzianskya ovata 'Orange Eye' or as the cultivar with no specific epithet. I am having difficulty tracking down definitive information on this taxon. Elsa Pooley describes Zaluzianskya ovata as "sometimes with a brilliant round orange 'eye'", in Mountain Flowers - A Field Guide to the Flora of the Drakensberg and Lesotho. My observation is that the plants I am growing are very similar to the typical Zaluzianskya ovata, but have a somewhat looser, trailing growth. More often, I've seen tight-mounded forms. Note that this seems to be the opposite of reports I have read online from other gardeners.

Tamara Bonnemaison's note: While editing this entry, I stumbled across an article (PDF) about Kirstenbosch Botanic Garden in South Africa. Written for Gardens Illustrated, the article features the stunning photographs of Claire Takacs. Seeing Claire's photos of Zaluzianskya ovata and some of the other species at Kirstenbosch brings visiting this garden to the top of my bucket list. I would love to stroll through the garden in the evening, as the Zaluzianskya ovata begins to unfurl its flowers and emit its strong, spicy scent. For more photos of South African plants taken by the talented Claire Takacs, visit the Kirstenbosch gallery on her web site: Claire Takacs.

Mar 20, 2015: David C. Lam Asian Garden

Actinidia deliciosa in David C. Lam Asian Garden

Only a few days after I gave a presentation to UBC's Friends of the Garden where I included this image and explained that sun rays through fog were rare in the Garden, the phenomenon occurred again.

Like the linked image above, this is another example of the (I hope, subtle) use of tone mapping in order to bring the image close to what our eyes may see (and brains interpret) compared to the camera which cannot handle this range of light in a single exposure.

The woody vine in the photograph is a male plant of the fuzzy kiwifruit, or Actinidia deliciosa. It ascends along a trunk of our locally native western hemlock (Tsuga heterophylla). A female plant is nearby, and through the autumn and early winter, that plant becomes laden with fruits very much like one might find in the store. However, most of the fruits are produced at heights above 6m (20ft), and are impractical to harvest. Squirrels make attempts, though most often they just end up taking a few nibbles and then cleave the fruit from the tree. The fruit then rots on the ground below.

Back to the male: this particular plant has had a rough winter. Where it previously ascended about 15-18m (50-60 ft.), it has collapsed down to about that 6m mark. The hemlock trunk above has been denuded of branches with the descension of the tangled mass of the vine, while the pathway below has been inundated with dripping sap from injuries to the plant where the upward flow of sap has been broken.

This kiwiplant is part of one of the feature collections in our David C. Lam Asian Garden: woody climbers (lianas). In addition to Actinidia spp., other Garden plantings include Rosa spp., Lardizabalaceae, Clematis spp., and Vitis spp. One group that is now absent is Hedera spp. (the ivies), as one species is locally invasive. Any former Hedera plantings were removed about a decade ago, as a precaution against introducing another troublesome nonnative to local plant communities. The remaining woody vines are also monitored, however, as part of an aggressive vine management policy within the Garden. If (when) a liana becomes either too burdensome for the tree it is ascending or (much more rarely) seedlings are noticed, the vine is cut back to ground level and forced to regrow from the base. Today's Actinidia deliciosa reveals that this is also occasionally more or less induced by the plant itself.

Mar 19, 2015: ×Cystocarpium roskamianum

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

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

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

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

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

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

Mar 18, 2015: Elaeocarpus angustifolius

Tamara Bonnemaison writes:

Clearly I love seeds and fruits; I could not resist writing about the unusual blue fruit of Eleocarpus angustifolius when Susan Collins (aka jungle mama@Flickr) posted this stunning photo of the fallen fruit on a bed of leaves. I am also featuring a photo by Drew Avery@Flickr that illustrates the leaves and some of the growth habit of this tree species. Thanks Susan and Drew!

Elaeocarpus angustifolius, or blue quandong, is a rainforest tree found in eastern Australia. It is quick to grow, reaching a height of 50 meters, and performs a key role in regenerating the rainforest after disturbance. In addition to the intriguing qualities shown in the photographs, this species also has beautiful fringed white flowers and stately buttressed roots.

The fruits of Elaeocarpus angustifolius, writes David W. Lee in a paper (PDF) published in Nature (Ultrastructural basis and function of iridescent blue colour of fruits in Elaeocarpus), achieve their colour in a very unusual way. While nearly all blue plant parts contain a pigment, the fruit of the nearly 60 species of the Elaeocarpus appear blue because their cuticles reflect blue light, in much the same way that peacocks (Pavo cristatus L.) and some beetles appear blue. Key to the iridescent blue qualities of Elaeocarpus fruit is the iridosome, a layer beneath the fruit's outer cell wall that consists of parallel rows of translucent strands of just the right thickness and spacing to reflect only blue light. Lee posits that the evolutionary advantage of iridescent colour (as opposed to pigmented colour) are twofold: first, the brilliant blue colour is highly visible against a backdrop of green foliage, even persisting after the carbohydrate-rich mesocarp has been consumed. Second, most fruits are only able to photosynthesize when green, but by achieving colour through iridescence, the fruit of Elaeocarpus are able to continue to contribute to the plant's carbon economy even when fully ripe.

Another, unrelated species that has iridescent blue berries is Pollia condensata. This article in Wired explains how the "natural world's most intense colour" is produced. It seems the principles behind Pollia condensata's fruit colour are similar to the blue quandong.

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