“Powerfully fragrant” is used to describe the scent of this winter-flowering shrub. Selected as a self-pollinated seedling of Daphne bholua 'Gurkha' by Alan Postill of Hillier Nurseries, the name honours his wife – I hope she was very pleased, because this cultivar has since gone on to receive a Royal Horticultural Society Award of Garden Merit.

If the fragrance is so compelling (and it is, in the majority of species in the genus), why are there few Daphne species used in the landscape? Two reasons come to mind from what I've been told: 1) protocols for mass commercial propagation of many Daphne species have yet to be discovered so current production requires labour-intensive processes, and therefore high prices; and 2) susceptibility to fungal pathogens. UBC Botanical Garden and Centre for Plant Research's Dr. Andrew Riseman and his doctoral student, David Noshad, are researching both of these difficulties with an eye to expanding the palette of Daphne species and cultivars available to gardeners. As part of their research, they've sourced a number of difficult to find species of Daphne. Many of these species will eventually form the backbone of the planned Daphne collection in the garden.

For gardening information on 'Jacqueline Postill', you can read this piece from the Royal Horticultural Society: Daphne bholua 'Jacqueline Postill'.

Natural history resource link: The Tucson, Arizona-based The Firefly Forest and companion web site, Wildflowers of Tucson. Firefly Forest was suggested to me by Angus Pratt at the Northern Voice conference, where he and I had a thought-provoking discussion on weblogs being used as natural history journals (with Firefly Forest being a prime example).

Heptacodium is monotypic, with only one species in the genus – seven-son flower. Unknown to Western science prior to 1907, it was encountered by E.H. Wilson during one of his expeditions to China. It remained unknown to Western horticulture until 73 years later when a group of scientists from the Arnold Arboretum and the US National Arboretum collected seed from a cultivated plant in Hangzhou Botanical Garden (the photograph is of a plant grown from one of those seeds). Stephen Spongberg, one of the members of the expedition, notes “...today there are undoubtedly more individual plants in cultivation in North America than in all of China” – you can read more of his recollections on Heptacodium from the expedition here.

The Kemper Center for Home Gardening has extensive photographs of the entire plant, including the flowers: Heptacodium miconioides.

To create this black-and-white, I used some of the Orton Imagery Techniques but did not digitally overexpose the image as suggested. Instead, I only did a 20% screen blend on the duplicate image. From the final image, I chose to use the red channel on its own for the b+w rendition.

Photography resource link: High Dynamic Time Range Images, a new photographic technique developed by local scientist Martin Krzywinski (discovered via The Luminous Landscape) – “Capturing the flow of time in a single frame”.

Today's image was photographed last September in a Venice market by Kimberly T of California (I'm not sure which Venice – California or Italy?). Many thanks, Kimberly!

A top-notch piece of writing on this plant exists online, so rather than trying to retell the story, I'm going to highly recommend you visit this page: Fractal Food: Self-Similarity on the Supermarket Shelf by John Walker, founder of Autodesk, Inc. and co-author of the well-known AutoCAD software. To give a hint of what you'll find on the article, John's divided his (released into the public domain) essay into a few parts: The Unclassifiable Romanesco, A Computational Universe?, Stalking the Vegetable with a Camera and Fixing Fractal Food – perfect Botany Photo of the Day fare.

Conservation resource link: “The Case of the Orchid Smugglers”, an article from Environment Canada's EnviroZine, tells the story of an illegal importation of protected orchids into Canada.

The feature of this rhododendron described by the epithet barbatum is barely discernible in this image. Barbatum translates to “bearded”, and refers to the hairs present on the petioles (the leaf stalks) – if you look closely, you should be able to see a few long hairs on the stalk of the leaf in the lower right.

Rhododendron barbatum is native to the Himalayas; for the taxonomic description, see Rhododendron barbatum in the Flora of China.

Photography resource link: Canon EOS Beginners' Frequently Asked Questions is a comprehensive suite of questions and answers particularly for new users of modern Canon SLR cameras, but much of it is useful for any photographer.

'Blue Streak' violet willow was featured on Botany Photo of the Day ten months ago, so I encourage you to (re)read the entry for Salix acutifolia 'Blue Streak' in early April of 2005.

The species is native to northern Europe and Asia; this cultivar was selected from plants in Russia, apparently sometime in the late 19th century (I haven't confirmed this against a Salix cultivar reference). Like all members of the genus Salix, the bark of the species contains salicin, a chemical from which the medicinal salicylic acid (important in skin care) and acetisalicylic acetylsalicylic acid, or aspirin, can be derived.

Natural history resource link: The Canadian nature observation program, PlantWatch. “The PlantWatch program enables 'citizen scientists' to get involved by recording flowering times for selected plant species and reporting these dates to researchers through the Internet or by mail. When you submit your data electronically, it's added instantly to Web maps showing bloom dates across Canada, so your observations make a difference right away!”

I've been waiting for a few months to feature this photograph from Dr. Chris Wolverton of Ohio Wesleyan University. Chris uploaded it via the BPotD Flickr Group Pool (original image – Chris, let me know if it's not alright that I cropped it). Thanks for sharing the snapshot, Chris – much appreciated!

As to why I held off until today to feature it, the answer is in the specific epithet. This is fruit of the cacao plant; the seeds inside are processed to produce cocoa, cocoa butter and, when the two are combined with varying amounts of other ingredients, chocolate.

Presumed to be native to the equatorial mountainsides of the Andes, Theobroma cacao is now cultivated in many tropical regions of the world. The largest producer is the Ivory Coast, accounting for over 40% of production (but at a cost: see “War Inflates Cocoa Prices but Leaves Africans Poor”, an October 30, 2002 article from the New York Times).

For an excellent overview of the economic botany and history of chocolate, check out Exploratorium's “The Sweet Lure of Chocolate”. And, as always, Purdue University's Center for New Crops and Plant Products also has an informed account: Theobroma cacao.

Photography resource link: Views of the Northeast by Ana Licuanan features several galleries of images from the northeastern US. “Enchanted Forests” contains my favourites, but there are plenty of other gems to be found.

I received a request from a galanthophile to feature a snowdrop on BPotD, so here's one from UBC. The UBC garden has a half-dozen or so different kinds of snowdrops, a number that pales in comparison to the roughly one hundred and sixty different cultivars at Colesbourne Gardens in the UK. With that many cultivars, you might expect a large range of forms and sizes. The reality, though, is that the differences between cultivars can be extremely subtle. The requirement to appreciate detail and subtlety is part of the attraction for galanthophiles.

Snowdrops are native to Europe and Asia Minor. As M.J. Harvey writes in a book review of “The Genus Galanthus” for Botanical Electronic News No. 250, that distribution resulted in a delay in the scientific understanding of the genus. Scientists on one side of the Iron Curtain did not have ready access to the live plants or herbarium specimens from the other side (and vice versa), so no one could compile a complete overview. This changed in the 1990s, facilitating the taxonomic work required for (and subsequent publication of) the monograph of Galanthus reviewed by Harvey.

Botany resource link: A biography of Dr. Katherine Esau, pioneering plant anatomist (yes, she did write the textbook on the subject!). A fascinating story of an accomplished scientist.

A follow-up to the post on Eriophyllum lanatum, these are photographs on the same island by Sheila's friend and co-kayaker, Stephanie Meinke. Thank you, Stephanie!

As Sheila noted to me, these plants were “growing in rocky crevices and depressions wherever a little bit of soil could accumulate”, a similar phenomenon to what was mentioned in this entry on lichen diversity. Over time, most biologically barren surfaces will eventually be colonized by some living pioneers. These pioneers are often (partially) replaced by a succeeding wave of other organisms, which are in turn succeeded by others and so on - a process termed succession. As mentioned by Brent in the comments of the Eriophyllum entry, the nearby Winchelsea Islands sustain a Garry oak woodland community of plants, while these seemingly do not, i.e., the Winchelsea Islands are at a later seral stage (a later stage in the successional process).

Knowing that the Winchelsea Islands are larger in area than the Ada Islands and assuming 1) both groups of islands have the same geological origins and substrate (a fairly safe assumption); 2) the surfaces of both groups of islands have been exposed from the ocean for a similar length of time (a not so safe assumption); and 3) the Winchelsea Islands peak higher than the Ada Islands (could someone please confirm?), what do you think are the factors that have prevented the Ada Islands from going through the successional stages that would allow them to similarly host a Garry oak woodland forest?

A quick note from Olduvai George: Happy Birthday, Charles Darwin.

Photography resource link: While browsing in a bookstore a couple days ago, I was delighted to discover “Tree – A New Vision of the American Forest”, by writer-photographer James Balog. When someone takes an entire day to photograph a tree section by section, you can imagine the result is going to be something spectacular. It is. Site navigation is a bit tricky, but check out the section on Trees – two of my favourites are "Stagg" Giant Sequoia and Sycamore. As an aside, there is no Amazon link because I've decided such a program isn't the right thing for UBC BG in most cases (and I will be removing most of the few existing links to Amazon from the site).

Depending on your perspective, Abeliophyllum distichum is either a rarity or fairly common. If you are familiar with the plant from a horticultural or gardening background, white forsythia is used ornamentally for its spray of white flowers in late winter / early spring (Paghat has a good gardening write-up for white forsythia). However, from a scientific perspective, Abeliophyllum distichum is rare indeed. Restricted to seven known sites in Korea, its future is tenuous. Yong Shik Kim and Mike Maunder have written an excellent account of the species and its history.

Botany / art resource link: If you've some spare time this weekend, you could do worse than spending it on the Rare Books from the Missouri Botanical Garden Library. Also, it's the first time I've seen a garden other than UBC use some of the web-based services or tools available. They've been using del.icio.us to tag the illustrations for annotation and filtering. Oddly enough, I had the same idea for BPotD yesterday after seeing a demo of a soon-to-be-released service while at Northern Voice. I'll add a reminder that I currently use del.icio.us to keep track of all the BPotD resource links.

I mentioned sacrifice in the Eurya japonica entry a couple of days ago. For today's photograph of 'Purple Cape' cauliflower, I had to step into the raised beds in the Food Garden. Thankfully, the smell from the manure applied to the beds wasn't as potent on Thursday as it was when freshly applied on Tuesday (the day I initially sought out the cauliflower for a photograph). I'm trying to recall when Tony Maniezzo (the horticulturist who is responsible for the Food Garden) originally suggested a photograph of this cauliflower. Was it Monday afternoon or was it after the application of manure on Tuesday...?

'Purple Cape' cauliflower is a heritage variety. The country of origin is apparently disputed (either South Africa or Italy), though it was first introduced to England circa 1808.

On the topic of heritage seeds and plants, this year's Seedy Saturday events are starting in communities across Canada (I see my old hometown is holding one tomorrow!). Seedy Saturday is a series of independent public events held for the purposes of swapping heritage seeds (thereby helping to preserve them) and learning about agricultural heritage and biodiversity conservation.

In BPotD news, I'm speaking about Botany Photo of the Day in two upcoming conferences. The first is this Saturday at Northern Voice (held here in Vancouver), where I'm part of a panel on Blogging in Education. The second conference requires a bit more travel: Museums and the Web 2006, being held in Albuquerque from March 22 to 25.

The reason that I mention the latter now is because I'm taking two weeks off on either side of the conference to travel through (and photograph for BPotD) Oregon, California, New Mexico, Utah, Arizona, western Idaho and eastern Washington. I'm planning to leave a lot to fortune on the trip (esp. the weather since the itinerary will be tight); it already looks like I struck out with the desert wildflowers this year. As Phillip mentioned in the BPotD comments recently, there is a record dry spell in Arizona. Despite not having brilliant displays of colour or rain-induced rarities in some places, I'm sure there will be plenty of interesting plants and landscapes along the way. If you have suggestions for (accessible) sites to visit in any of those states, I'd be interested to hear from you. I'll be travelling by car (so no off-roading), but day hikes to exceptional sites are okay.

Photography resource link: For inspiration, Photographs of Lyme Regis, Devon and Dorset by Lois Wakeman – purposefully subtle, yet more compelling for being so.

Thanks to Sheila Williams who sent along this photograph of woolly sunflower. Sheila and a friend kayaked to the Ada Islands last summer (close to the Winchelsea Islands, near Nanaimo, British Columbia). There, they discovered these treasures.

Eriophyllum lanatum also has a more whimsical common name: Oregon sunshine. It is native to western North America, growing from seaside elevations (as seen here) to 3500m (~11500 feet).

The classification of Eriophyllum lanatum and all of its subspecies, varieties and forms has historically been messy – at one time, over seventy-five different names had been applied to what is now roughly recognized as ten morphological varieties. Unfortunately, the need to apply a name to any particular plant masks the biological reality. Eriophyllum lanatum is a species complex – a group of closely-related intergrading taxa.

Species complexes are ideal groups to study the processes of evolution, as the entities involved may be undergoing speciation into distinct entities, i.e., new species. In the intervening time, however, it can be a nightmare to put a name to these intergrading entities; a biological name is intended to represent something that can be clearly delineated, and members of species complexes often defy clear delineation. Still, on the edge of this plant's native distribution where the inflow of new genetic material is restricted by distance, distinct entities can be more easily recognized, hence the assertion that all of British Columbia's plants are of the variety lanatum. At the centre of the range in California, however, things are more complicated. Entities morphologically intergrade and can produce hybrids, though there can be barriers to the latter: see Mooring, J. 2001. Barriers to interbreeding in the Eriophyllum lanatum (Asteraceae, Helenieae) species complex. Am. J. Bot. 88:285-312.

Botany / photography resource link: Photographic Atlas of Plant Anatomy – a compilation of hundreds of categorized plant anatomy images from the research and teaching careers of Dr. John Curtis and Dr. Nels Lersten, with help from Michael Nowak. Even if you don't understand what you are looking at, the images of plant tissue and cells at the microscopic level has a beauty all its own.

Let it never be said that I do not make sacrifices for BPotD. To get this close to a eurya in flower requires setting aside the urge to leave quickly. In the garden's interpretative sign for Eurya japonica, the scent is described as “exceptionally malodorous”. I think I can go one step (but not two) beyond that here – part of the scent is metallic in nature, like that of wet rust or tin. It is safe to assume that the odour of the flowers is the reason for the removal of the eurya growing near the doors of the Shop in the Garden. This was done as part of a recent redesign of the garden's front entrance.

During the process of confirming the family information for this genus, it became apparent that the interpretative sign requires an update. On the sign, the plant is described as a camellia relative – this is now only true in a broad sense. A combination of recent molecular work and a review of the morphological properties has clarified the evolutionary relationships of Eurya, such that placing it in the Theaceae (the tea or camellia family) is no longer supported. Instead, the Pentaphylacaceae is a far better fit. I note with some interest that the Pentaphylacaceae have the familial property of being aluminum accumulators; I wonder if there is a correlation between the scent of the flowers and that property.

Botany resource link: It's been a resource link before, but it certainly deserves the honour of being the first site to receive a second mention – Scott's Botanical Links celebrated ten years of entries yesterday. Since February 7, 1996, Dr. Scott Russell of the University of Oklahoma has been compiling a list of botanical resources on the web. I highly recommend subscribing to the site via email or the RSS feed.

Updated February 7, 2006 at 4:06pm: Thanks to Doug who suggested some alternatives to my tentative identification in the comments, I went out and re-examined the lichen. I'm now reasonably confident that this is Evernia prunastri and not what I misidentified it as, Platismatia stenophylla. I think it's an opportune time to remind you that I'm more interested in having the correct information available to BPotD readers than I am in being “right”. If I ever post something that doesn't sit right with you or if you can add something (including a different perspective!), please comment – Daniel.

Mysteries abound, today. Let's start with the lichen. I'm fairly certain it is Platismatia stenophylla or ribbon rag lichen, but it's difficult to confirm. I've only one image in a book to compare with, since there are no results in image search engines for either Platismatia stenophylla or a synonym, Cetraria stenophylla. Nope, I was wrong – Evernia prunastri is a better match. This taxon's native range of occurring in coastal forests of temperate western North America matches, as does its property of growing on trees – so perhaps I'm right. To help be certain, I'd have to break out the chemistry kit. As I've noted before, lichen identification is often aided by observing reactions to chemical reagents (if you ever see a person in a forest with a satchel of small bottles covered by eyedroppers, you will have encountered a bona fide lichenologist).

For Platismatia stenophylla Evernia prunastri, confirming that it is either KC+ (yellowish) or KC- would help verify my tentative identification. This test would involve first wetting the thallus (body) of the lichen with a ten percent potassium hydroxide (KOH) solution, or the K test. The C test would be a dose of bleach, that is, a solution of sodium hypochlorite. If there is no apparent reaction to the bleach on the KOH-soaked lichen, another bit of evidence would be in agreement with the identification. If the test was positive, however, the thallus would change colour. For this lichen, a change to a yellowish colour would help confirm. If it changed a different colour, I'd be back to scratching my head over other possibilities.

The Oregon Coalition of Interdisciplinary Databases has a good entry on Evernia prunastri, and image search comparisons also suggest a match.

The hybrid witchhazel poses a different sort of mystery. Occasionally in the past few years, some staff time has been invested in attempting to verify that a cultivar 'Fireglow' exists. So far, we've come up short. Staff from the garden have searched online, reviewed the horticultural literature and even contacted the International Cultivar Registration Authority for Hamamelis, all to no avail. Its existence as a cultivar could be due to something as simple as a clerical error in its thirty year history. Or, perhaps it is a locally-developed selection, named and sold only to a select few three decades ago (it was purchased from a now-closed local nursery). Too, it could be a misidentification and actually an entirely different cultivar. We haven't yet figured it out.

Photography resource link: Tripod Therapy, an article by Rod Barbee for Nature Photographers Online. Good advice regarding one of photography's most important tools.

This sweet-scented, winter-flowering viburnum is not named after the director of a number of Abbott and Costello films. Instead, the name honours a former assistant curator in the Royal Botanic Garden Edinburgh. The Royal Horticultural Society's account for Viburnum ×bodnantense tells the story.

Photography resource link: Subject Matter and Print Size, an essay by Alain Briot for The Luminous Landscape (part of his Reflections on Photography and Art series).

There are roughly one thousand species of Rhododedron in the world. Of these, nearly six hundred can be found in China. Just over four hundred can only be found in China (endemics); Rhododendron ririei is one of the these, native only to the southwestern portion of Sichuan.

Like Rhododendron moupinense, it is one of the earliest flowering rhododendrons locally.

The scientific description is available online from the Flora of China: Rhododendron ririei.

No resource link today – instead, I'll invite you to read the tributes and stories from some of the garden's researchers, staff and Friends of the Garden for the recently deceased Christopher Lloyd of Great Dixter: Christopher Lloyd (Christo) 1921-2006.