The specific epithet for redbud hazel, cercidifolius, implies that the “leaves are of Cercis”; the resemblance is such that a quick glance at the shrub can lead to misidentification during certain times of the year. However, when the chlorophyll in the leaves of Disanthus cercidifolius begins to break down, a panoply of colours are revealed dissimilar to the autumn colours of Cercis.

The genus Disanthus is monotypic, meaning it contains only one species (compare with a monotypic family – it would only contain one genus, like the Nepenthaceae). Similarly, it is recognized that Disanthus has no close relatives within the witch-hazel family, relatively speaking. For more on its phylogenetic relationships, see: Li et al. 1999. Phylogenetic relationships of the Hamamelidaceae inferred from sequences of internal transcribed spacers (ITS) of nuclear ribosomal DNA. Am. J. Bot. 86:1027-1037.

Photography resource link: The USDA's Natural Resources Conservation Service Photo Gallery contains a suite of categorized photographs which are made available for use free of charge.

Another milestone today – this is entry number two hundred.

Decaisnea insignis is commonly known as “dead man's fingers”, a name inspired by its fleshy blue fruit, which ripen near Halloween and dangle menacingly from its branches. The follicles (pod-like fruit) contain black watermelon-like seeds surrounded by an edible, clear pulp. I would describe the taste as not unpleasant, but bland. The texture is more interesting – akin to jelly.

The akebia family, or Lardizabalaceae, contains eight genera. Decaisnea is an oddity as the only shrubby genus among a clan of woody climbers. Like most other members of the family, Decaisnea is native to southeast Asia, and in the case of Decaisnea insignis, western China. Two members of the family are an interesting botanical exception: Lardizabala and Boquila are native to Chile, forming what can only be called an odd biogeographical distribution for the family, as Chile and Asia were never in historic continental proximity.

The emerging foliage was previously featured on BPotD: Decaisnea insignis.

Botany resource link: UBC's Biology 321 – Bryophytes course site. Many images of mosses and liverworts, along with some introductory information about moss and liverwort morphology.

Even though the flowering season for the greater yellow lady's slipper is long gone, I'm going to sneak in this out-of-season photograph. I imagine that I'll be sharing a few non-seasonal images from time to time during the winter, just in case your favourite BPotD entries are showy flowers.

This photograph was taken July 20, 2004 in southern Manitoba, several weeks after the normal flowering season should have concluded, thanks to a cool, wet spring and early summer.

If you are familiar with this plant, you may have learned it as Cypripedium calceolus var. pubescens (e.g. University of Wisconsin-Madison species page). The Connecticut Botanical Society succinctly describes why the name has changed, and refers to the account of the Flora of North America project: Cypripedium parviflorum and this particular variety, Cypripedium parviflorum var. pubescens.

Here's a challenge regarding the genus Cypripedium: name the only two states in the lower 48 (excluding the District of Columbia) where you cannot find a member of the genus Cypripedium growing natively. One of the states is very surprising. I think all provinces and territories in Canada have at least one member of the genus (as does Alaska), but I need to check some of the Arctic floras to be certain about Nunavut.

A few recent items of interest regarding Botany Photo of the Day:

• Tangled Bank Number 39 is up and running on The Questionable Authority weblog. I submitted the recent entry on Acer circinatum to join the collection of roughly two dozen other links to recent science-based writings and images. Well worth the visit to see what other science writers have to offer!
• There were a couple new comments yesterday on the BPotD entry for the lichen Letharia vulpina. Susanne Alterman, a grad student at the University of California, Santa Cruz, is seeking help collecting specimens from across North America – if you can pitch in, I think your contribution would be greatly appreciated. She has instructions and forms on her site.
• Back in early May, I was humbled to be able to entertain Dr. Daniel Pauly, his wife and guests from Germany on a tour of UBC Botanical Garden, which I noted in the entry on Philadelphus delavayi. UBC announced two days ago that Dr. Pauly will be the first Canadian to receive the International Cosmos Prize (biography of Dr. Pauly via the Cosmos site). The biodiversity tragedy unfolding in the world's oceans is only being brought to light due to the work of scientists such as Dr. Pauly.

Nature / science resource link: Since we're on the topic of oceans, check out Bone Eating Snot Flower via Deep-Sea News. As you might guess, not a flower, but rather a literal interpretation of the name Osedax mucofloris, a species of zombie worm.

This is one of my all-time favourite photographs.

The capsules of this unidentified species of Epilobium (or willow-herb) have split open, revealing a mass of seeds tufted by silky white hairs. As you might guess, the hairs aid in wind dispersal. Since wind-dispersed seeds can travel long distances, this species is likely fairly generic in the conditions it requires for germination and growth; seeds which only travel a short distance are more likely to find conditions similar to the parent and can therefore be expected to have more specific growth requirements. There are disadvantages to the short-distance dispersal strategy, though, particularly for perennial plants; these include potential for inbreeding and competition for resources.

Photography resource link: Petteri Sulonen's Why Most Landscapes Suck. I should qualify this link by saying that even though I add a link to a photography resource, I may not actually agree with some or all of the opinions therein. I do, however, subscribe to the notion that thought-provoking articles are worthwhile, particularly if they force (re)examination of ideas and beliefs.

Updated Oct. 20, 2005 at 1:30am: Welcome to readers of Tangled Bank No. 39! If you don't know what Tangled Bank is, it's a biweekly collection of recent science-based writings and images from weblogs around the world, hosted by a different weblog for each edition – it's a great way to find out about other science weblogs!

Updated Oct. 17, 2005 at 8:05am: Welcome Boing Boing readers! If you're new to the site, you might like to check out a few other photos such as chocolate vine, 'Bright Lights' Swiss chard or the first BPotD, Melliodendron xylocarpum. Also, have a gander at the BPotD widget! – Daniel.

The idea and concept for this photograph of variability in autumn leaf colour of vine maple is thanks to Dan Otis, who assembled the collection for his own photo during the recent Maple Society Symposium field trip. Dan kindly allowed me to also take a picture, so I'm sharing it with you. Bear in mind, though, that if you like the image, please be sure to thank Dan in the comments, and not me – after all, all I had to do was show up and press a button after he did the work. This is the third in the series of three shots on Acer circinatum, previously featured here and here.

From a previous entry, Anthony asked “Why would being in the woods affect the color of the maple leaves?”, since I'd mentioned that the vine maples in the woods were yellow in autumn colour, while those in exposed sites were a brilliant orange-red. For an outstanding article on the topic, check out “Autumn Colours – Nature’s Canvas is a Silk Parasol” (PDF - 750K). Written by Dr. Rob Guy and Jodie Krakowski of UBC's Faculty of Forestry for UBC Botanical Garden's journal Davidsonia (I'm working on its new web site with open access to all recent articles), I'll quote the abstract to answer the question in brief:

“The variety and widespread nature of leaf colour change in autumn has led to investigation of the biochemical pathways and compounds responsible. The synthesis of bright red colouration initiated by longer nights prior to leaf abscission in deciduous species points to some adaptive value for this expensive ephemeral trait. It is hypothesized that during the breakdown of the unstable chlorophyll and the dismantling of the nutrient-rich photosynthetic apparatus, red anthocyanins provide a more biochemically parsimonious alternative to the elaborate xanthophyll system. This alternative enables leaves to screen out excess light energy and circumvent photooxidative damage to leaf cells, while allowing photosynthesis to persist at low rates in support of metabolic processes and phloem loading required for nutrient resorption from leaves.”

In other words, the formation of red pigments in the autumn provides protection, preventing the too-rapid breakdown of chlorophyll which could occur in exposed (read: excess light) areas. As you can clearly see in the leaf in the upper right, the bottom-right corner has the pattern of the leaf above. Where the leaf above shaded this leaf, no red pigments were produced. Where the leaf was exposed, bright red anthocyanins were formed. To take this to a broader perspective, vine maple trees in shaded forests and under low light conditions have little need to produce red pigments, as the breakdown of chlorophyll can occur at a modest pace. However, vine maples in exposed sites turn flame orange and red, so that the pigments produced will slow the rate of chlorophyll breakdown. The leaves in this photograph are from trees that are partially exposed, hence the attractive blend of colours.

No botany resource link today, since I'm answering one of Victoria's questions regarding plant taxonomy and names: Why is it that so many plants are in limbo as to their correct/finalized/accepted names?

I recently gave a lecture on the topic, and I had stated there were two broad reasons. I'm going to split one of those reasons into two, so I'll give three reasons here. Please know, though, that any one of these reasons can be combined with another one or all three can occur in a particular scenario.

The first reason is analogous to bookkeeping. Imagine a scenario where a name is published for a plant and it is later discovered that another taxonomist had already published the name describing a different plant (or, as has happened occasionally, the same taxonomist!). The most recent name would have to change since the older name (assuming everything is scientifically valid) would have priority. Or, imagine that someone names a plant that had already been named. The latter name is dropped as a synonym of the original version. Essentially, these rules try to enforce the notions that each species of plant has only one validly published name and that each name can only apply to one species of plant. As you might suspect, the modern days of rapid communication and information warehouses mean that names needing to change due to bookkeeping are now not a big proportion of the whole.

Disagreement about whether a subset of a species is distinct enough to be a subspecies or variety, and if so, which one of the two it should be is the second reason. I'll direct you to this page from the Brooklyn Botanic Garden on “How Plants Are Named” for a discussion on the differences between subspecies and varieties. Frankly, this is a reason that makes me roll my eyes, because it causes much consternation over a relatively trivial matter. Should it be Pallaea glabella subsp. simplex or Pallaea glabella var. simplex? From the BBG link, you'll note that some scientists have tried to define when each should be used. Other scientists argue that only one or the other is needed, and they then refuse to recognize the other when publishing floristic works or databases, so in the fern species above, some scientists would use subspecies and others would use variety. This reason for instability of plant names makes little sense in the face of the overwhelming loss of biodiversity.

The final reason is the biggie. You first of all need to know that the modern system for scientifically naming plants predates Darwin's and Wallace's Theory of Evolution. Plant nomenclature did not therefore have mechanisms to reflect evolutionary relationships, though plants were recognized as being part of identifiable natural groups (e.g., composites or legumes) and very similar plants shared the same genus. As the conceptual lynchpin of modern biology took hold, however, the same general system of plant nomenclature was mapped onto evolution, such that this general principle emerged: plant names and classification should reflect evolutionary relationships.

The utility of this principle is immense, simply because closely related plants share similar characteristics. Given a scientific name for an unknown plant, a taxonomist can make several predictions about its morphology. A biochemist can predict the compounds she might be able to extract or use the knowledge of plant relationships to target groups of plants in search of a particular chemical. A horticulturist can use methods from propagating related species to increase the chance of successful propagation, perhaps helping conserve an endangered species. I'll expand on this area when I answer Victoria's question about the importance of taxonomy, but it will suffice for now to say that the predictive value when nomenclature and classification are tied to evolution is supremely important.

The downside, however, of tying the two together is that our understanding of evolutionary relationships both continues to develop and will doubtfully ever be completed. As new techniques are developed (e.g., rapid analysis of nucleic acid sequences) or new evidence is found (e.g., fossils, new species), different hypotheses may be formed about evolutionary relationships. Given that plant names and classification should reflect evolutionary relationships, the name of a species, genus or family may change to reflect the new hypothesis. It so happens that the rapid accrual of information through modern molecular techniques is causing a significant clarification of plant relationships, therein also requiring significant changes to plant names recently. Will it ever settle down? Perhaps, but it is hard to predict what future techniques might be developed to determine relationships. I suspect, though, that the massive loss of biodiversity will sadly make things simpler for our descendants due to smaller datasets.

Most members of the spike-thorn family are tropical, but a few genera, including Euonymus, are well-represented in temperate climates – in some areas, too well-represented. Though the striking foliage of compact burning bush has high ornamental appeal, it's been observed to be an invasive plant in eastern North America. This behaviour has not been noted in the maritime climates of western North America, where it is a Great Plant Pick (PDF) | GPP web site.

Photography resource link: Michael Reichmann of The Luminous Landscape refutes the notion that everything worth doing in photography has already been done in “Been There, Done That”.

The Apple Festival is on today and tomorrow. If numbers of people visiting the garden is the measure, it's the biggest event of the year (and certainly one of the biggest within the entire university) – I do have to say that 13,000kg (28,000lbs) of apples is quite a sight. Anyway, you'll have to excuse me if I've been a bit brief recently and for possibly being abbreviated the next couple days.

The 'Jonagold' apple is a half-sibling to 'Elstar', as it also has 'Golden Delicious' as one parent, with 'Jonathan' as the other. 'Jonagold' was introduced by the New York State Agricultural Experiment Station, and later received an “Outstanding Fruit Culitvar Award” from the American Society for Horticulture Science.

Botany resource link: Plant Hormones goes into great detail into the chemistry and physiological effects of plant growth regulators.

Commonly known as either nerine or Cape flower, Nerine bowdenii is a native of South Africa. The name of the genus refers to the Nereids, or sea-nymphs, of Greek mythology.

Planted for an autumn display of pink colour, this mass of flowers is from the UBC Alpine Garden.

Photography resource link: For inspiration, the floral abstract photographs of Duncan Smith and Adam Clutterbuck.

Zinnia haageana 'Old Mexico' is an All-America Selections Winner from forty-three years ago –, a cultivar that has stood the test of time. Considering its performance in trials done by The Gardens at the University of Georgia, that decades-long popularity is no wonder. It has performed similarly well this year at UBC.

Autographa californica is the moth, commonly known as the alfalfa looper. The sickle-shaped white spot on the wing is an easy diagnostic feature.

The adult moth does no damage, while the caterpillar is rarely present in numbers large enough to have an economic impact on crops. In fact, the University of California Integrated Pest Management Program for cotton and loopers states: “Moderate populations of loopers may be more beneficial than harmful, as they support populations of natural enemies that also attack the more destructive bollworms, budworms, and beet armyworms.”. Similar statements are made on the site regarding loopers and other Californian crops such as lettuce, artichoke and tomatoes. Along with a suite of predators, alfalfa looper is also susceptible to a baculovirus.

Botany / conservation resource link: Botanic Gardens Conservation International “brings together the world's botanic gardens to work for plant conservation through science, education and horticulture.”

How did I take this photograph? Very carefully. This Japanese honey locust is located near a rubbish bin, an attractant to the local population of yellow-jacket wasps. Since the bin is sealed, the wasps instead congregate on this tree – one landed on these pods a few seconds after taking this shot. Oddly, most of these 20cm (8in) long pods had been (or were being) chewed down by the wasps, particularly those pods in less exposed areas.

This is yet another one of those plants in which the scientific name has not been settled on. As you might suspect from the name koraiensis, this is the Korean morphological variety of the plant identified as distinct from the rest of the species by Nakai (it also grows in China and Japan). Authoritative taxonomic databases do not reflect Nakai's interpretation, instead placing it strictly as the species Gleditsia japonica (and here).

In Phylogenetic relationships in Gleditsia (Leguminosae) based on ITS sequences (Am. J. Bot. 2003;90:310-320), Schnabel et al. are not able to provide a definitive answer as to whether the variety koraiensis should be recognized taxonomically, to wit:

“In addition, our two molecular data sets show different relationships among the G. japonica accessions. The cpDNA data suggest that the South Korean and Japanese accessions cluster separately from the Chinese accessions. In contrast, all the analyses of ITS data alone and the ML analysis of combined data place the South Korean accessions in one clade and the Japanese and Chinese accessions in a second clade. More extensive sampling of G. japonica, especially in China, will be necessary to determine whether any of the subspecific designations of G. japonica are phylogenetically justified and to clarify the taxonomic complexity of this group.”

It needs to be noted that clarifying the taxonomic complexity at this resolution was not the main goal of their work, as they were looking at Gleditsia more broadly.

Fortunately, acquiring more data for this species is achievable, as it is not threatened. Perhaps the name will be “finalized” one day. For now, I've used the varietal koraiensis, as it adds a tiny bit of information about this particular plant at UBC.

Nature resource link: I linked to it five months ago, but it's worth mentioning again since there are so many new readers of BPotD – “Beauty and the Botanist”, an essay by the late Dr. Stan Rowe (full disclosure: his biography was written by my uncle). If you've ever wondered about BPotD's tagline, “In science, beauty. In beauty, science. Daily”, this is the essay that serves as the inspiration.

The apple cultivar 'Elstar' is the result of a cross between 'Golden Delicious' and 'Ingrid Marie' made in 1972 in Wageningen, The Netherlands. It is now one of the many varieties of apples grown in British Columbia, primarily in the Okanagan and Creston Valleys. Despite being responsible for only 25% to 30% of Canada's apple production during the last decade, British Columbia accounts for 65% to 70% of all Canadian exports (Canadian apple production).

Although most apples grown are from only a dozen or so different varieties, many British Columbian orchardists also have a few trees of heritage or uncommon cultivars. Those few plants help supply the over sixty varieties of apples that are available for purchase and tasting at the annual Apple Festival at UBC, coming up next weekend. If you're a local, you absolutely need to attend.

Botany resource link: Apples, from Mark Rieger's Fruit Crops site.

Acer circinatum, second of a three-part series on this plant. The first can be seen here. The last of the series will include a written piece about the whys and hows of autumn leaf colours.

Botany / conservation resource link: H. Bruce Rinker's article entitled, “The Weight of a Petal: The Value of Botanical Gardens”. An excellent (but brief) article summarizing the benefits of research and conservation gardens, such as UBC.

Credit to “Weekend Gardener” of Coquitlam, British Columbia for this image of a “man-eating plant” (submitted via the BPotD Submissions Forum). Kind thanks!

As promised in this BPotD entry for the Asian Garden, here is another photograph of Petasites japonicus var. giganteus, or Japanese butterbur. As alluded to by Weekend Gardener in the written accompaniment to his submission, this plant can be an aggressive grower given the right conditions. I'm hesitant to attach the moniker “invasive” to it (like so many others have on the web), primarily because its ability to disperse is limited. That being said, it may indeed be biologically invasive in some areas, so caution should be exercised if you are considering growing it.

The size and structure of the leaves hint at the habitat ecology of the plant – moist soils in a shady forest. Large leaf surface area typically equates with a high rate of water loss, hence the need for moist soils. The large leaf surface area is also a mechanism for capturing as much available light as possible, a strategy typical of growing in shady conditions. The leaf itself is relatively thin compared with the sturdy similarly-sized leaves of some Gunnera. When considered in tandem with the surface area of the leaf, thin large leaves imply the plant cannot be exposed to high winds. Accordingly, forests offer protection from any potential mechanical damage or dessication caused by air movement.

Small note on the taxonomy – some excellent references suggest variety giganteus, while others use subspecies giganteus. I've used variety, but if anyone wants to convince me otherwise, I'd definitely listen to any argument.

Photography resource link: The work of Ladislav Kamarád, in particular the photographs from South America: Patagonia and Bolivia.

I promised some autumn colour, so here is Acer circinatum, or vine maple, growing in an exposed site within E.C. Manning Provincial Park. You can compare these trees with the ones in a shaded location featured on BPotD a few days ago. Just a slight difference.

An image planned for a future entry will be accompanied by a written explanation of why individuals of the same species colour differently. For today, though, just enjoy.

BPotD news item one: Tangled Bank Number 38 is up, this time hosted by Living the Scientific Life. Tangled Bank, if you've not heard of it before, is a collection of recent online scientific writing contributed by a number of authors. This time there are forty-one contributions, including the submission from Botany Photo of the Day, Biarum tenuifolium. You could spend an entire day reading all of the contributions – wish I had the time!

BPotD news item two: Dr. Scott Russell, who runs Scott's Botanical Links, has highlighted Botany Photo of the Day as his selection for October 5, 2005 (and he mentions the six month anniversary). Thanks, Scott – BPotD still has a long way to catch up to your nearly ten years of daily links and reviews!

BPotD news item three: I'm communicating with The Science Creative Quarterly, an online science daily, about collaboration between BpotD and SCQ (they're here at UBC as well). I'm sure you'll be hearing more about them in the near future, but for now, be sure to check out their bold site for its style and content.

Botany resource link: The Miracle of Fall from the University of Illinois at Urbana-Champaign Horticultural Extension is a comprehensive resource site about autumn colours that includes suggestions for foliage plants and foliage webcams(!). Discovered via the Librarians' Index to the Internet.

Rostrinucula dependens is a member of one of the most successful plant families, the Lamiaceae (see that distribution map for the family!) or Labiatae. However, Rostrinucula itself is uncommon – it is a genus with only two species, both endemic to China. Only available in cultivation during recent years, the plant has no commonly used name, though UBC proposes a couple in its interpretative sign for its plant.

Photography resource link: Colour Theory as Applied to Landscape Photography via The Luminous Landscape.