Again, a thank you to Katy S for sharing her photographs with us. This is the third in a series of six (or more!) featuring plants of Australia. Much appreciated!

I first have to mention I find this photograph reminiscent of last week's Isomeris arborea, particularly in terms of colour. Interesting, perhaps, that both the bladderpod spiderflower and this, the bent-leaf wattle, are species of dry, sunny habitats. Other similarities exist: leaf shape, habit (both are shrubs) and glaucous leaves (covered with a waxy coating, in this case causing a whitish colour). All in all, this is a textbook, if unspectacular, instance of convergent evolution: the accumulation of similar traits occurring in independent species as a result of adapting to similar ecological niches.

Where the two species diverge, e.g., in the flower shape and structure, it is generally safe to assume that dissimilar ecological conditions exist. Acacia flexifolia, like many wattles, is insect-pollinated by beetles, wasps and bees. Isomeris arborea, on the other hand, is visited by hummingbirds and bumblebees. Of course, it isn't as simple as that (if it was, there'd be fewer variations in flower shape and structure) – genetic barriers and restraints, along with additional ecological factors, contribute to the difference.

To read more about bent-leaf wattle, visit the Australian National Botanic Gardens page on Acacia flexifolia. World Wide Wattle has a more technical description of the species, as well.

Photography / biology resource link: 16 Mind-Blowing Microphotographs of Living Things, suggested by Stannous F. Thank you!

Today's photograph is again courtesy of Katy S – thanks again! Katy photographed this plant last January in the Kings Park Botanic Gardens in Perth, Australia. This is the second in a series of (now) five featuring Australian plants.

Rose mallee is a Declared Rare species of eucalyptus native to the northern part of Western Australia and within the bounds of the Southwest Australia Biodiversity Hotspot. Fewer than four hundred plants are known to exist in the wild (source: Australian Dept. of the Environment and Water Resources).

The Australian Dept. of E&W also notes the major threats for this species: “Threats to the Rose Mallee include land clearing and the drift from herbicides and pesticides sprays. The Rose Mallee is also threatened by the Root-rot Fungus (Phytophthora cinnimonii), a fungal disease that causes its roots to rot. Other threats include weed infestation, commercial seed collection, and predation by feral rabbits.” The conclusion? Any sort of plan to manage the remaining wild plants is necessarily complex, due to the number and scope of threats. It also suggests that because of the human mistakes of the past, the future of this plant species is dependent on the actions of the humans of the present, i.e., an interventionist approach is required, as opposed to a preservationist one.

Photography resource links: two different interpretations on the photographic adage, “If your photographs aren't good enough, you're not close enough”: Michael Reichmann of the Luminous Landscape on Understanding the Art of Cropping and Paul Butzi on Getting Closer.

For the next four days, perhaps more, BPotD will feature plants from Australia. Today's photograph is courtesy of Katy S, taken somewhere in Australia.

Where in Australia isn't too important. As noted in the comments on last year's BPotD entry on Cootamundra wattle, this species has invasive potential. Though the comments discuss its spread in California, it is similarly invasive in parts of its native Australia, making it one of those infrequent “invasive natives”. It is a fine illustration of the ambiguity of the word native. It is accurate to say it is native to Australia, but far more precise to say it is only native to a narrow ecoregion – a small corridor perhaps 50km (30 miles) wide – in southern New South Wales. Elsewhere in Australia where it has been introduced, it has proven to be invasive (information sourced from World Wide Wattle's page on Cootamundra wattle).

Strictly speaking, some might disagree with my use of the terminology invasive native, as a definition (see native weed) of the term suggests a different interpretation. In that glossary, invasive native is defined as a species that historically occurs in a certain area, but for some reason has exploded in terms of its population. One example cited is white-tailed deer in parts of North America, with present populations far exceeding historic numbers due to human-created landscape changes. Personally, I think the two terms should not be equated, with invasive native being reserved for those imprecise (but often necessary) instances when nativity is not defined by ecoregional areas, but rather by political boundaries.

Lilium columbianum, or Columbia lily, was previously featured on BPotD here and here.

Though I learned the common name for Campanula rotundifolia as bluebell, harebell is far more often used. This helps distinguish it from species of Hyacinthoides, in the Hyacinthaceae. On the other hand, the USDA PLANTS database uses bluebell bellflower, again demonstrating the variable nature of common names.

The distinctive bell shape of the flower in the genus Campanula (illustrated in these photographs from the Burke Museum: Campanula rotundifolia) earns its own morphological term: campanulate, or bell-shaped. Do note that the use of this term isn't restricted to members of this family.

A nod of appreciation to Amir A. from Israel for once again sharing a photograph! Thank you!

With a name like Pistacia, you might make a mental association with pistachio. You wouldn't be far off, botanically speaking. The pistachio of commerce is Pistacia vera, a close relative of this species. As mentioned in the Plants for a Future database, however, the fruit of Pistacia atlantica is not eaten directly – it has the flavour of turpentine.

This property is reflected in one of its many common names, the turpentine tree. Other English common names include terebinth, Mount Atlas pistache, Atlas pistachio and Mount Atlas mastic tree.

The UN's Food and Agriculture Organization has a database of economically important grassland species from around the world. It includes an interesting entry on Pistacia atlantica, with some of the information derived from a traditional Bedouin doctor.

Today's photograph from Descanso Gardens is thanks to van swearingen@Flickr (original photo | BPotD Flickr Group Pool). Much appreciated!

The families Cleomaceae (cleome family), Capparaceae (caper family) and Brassicaceae (mustard family) are all closely related. Depending on what reference you read, you may find today's plant, bladderpod spiderflower, in any one of those three families. Traditionally, it is most often placed within the Capparaceae sensu lato (in the broad sense), but I've opted for the Cleomaceae as it forms a well-defined group (scroll up on that page to read the taxonomy of these three families).

Not only is its family under disagreement, but so is its scientific name. I've chosen to use Isomeris arborea as it was used in the Jepson Manual, but the USDA PLANTS database uses Cleome isomeris.

The USDA PLANTS link contains more photographs of the plant, including images of the bladderpods the common name refers to. I might share my photographs of the bladderpods taken in Joshua Tree National Park (this is a plant of the southwest USA and Mexico) in a future BPotD entry.

A thank you to Rosa, aka contemplar@Flickr for contributing today's photograph from Jardim da Estrela (original image via the BPotD Flickr Group Pool). If you haven't visited recently, be sure to visit Rosa's weblog, Blog De Cheiros. Thank you, Rosa!

It is little surprise that this plant is growing in Lisbon, Portugal; it is named after Henri Cayeaux, who was the director of the Botanic Garden of Lisbon during the late 19th / early 20th century. Considering Cayeux's work with hybridization of other plants, it is very likely he was also the plant breeder responsible for this cross, thought to be between Dombeya burgessiae and Dombeya wallichii.

The common name for this plant is pink ball dombeya or pink snowball. One of its parents, Dombeya wallichii, has the common name of tropical hydrangea (though it is not a hydrangea).

This photograph taken in mid-September of last year is of the same tree that produced this leaf (abstract).

With a quick glance, you might mistake sweet gum for a maple due to a similar leaf shape. However, if you can't recall while taking a closer look that maples have opposite leaves and sweet gums have alternate leaves, you can always look for fruit – you won't mistake that for a maple!

In my mind, I referred to this plant as “the plant so big, it requires two photographs to capture all of it”. Not really, of course – at a height of up to 6m (20ft), it is quite possible to take a photograph with the entire desert agave in the frame. However, one has to do it from so far away that it doesn't look like much (or at least my attempts failed), considering that 5/6 of that height is the slender flower stalk. So, I'm only able to share a photograph of the inflorescence, in this case from an individual that was only 3m or so high.

Fortunately, other sites have photographs for you to examine. The Living Desert in Palm Desert / Indian Wells, California shares not only a few photographs of the rest of the plant, but also has an excellent factsheet on desert agave. The superb CalPhotos has thirty photographs of Agave deserti for you to peruse. I also love the illustrations of Agave deserti via the Flora of North America entry for the species.

On a different subject, this photograph was taken in Anza-Borrego Desert State Park. I note with concern that there is a movement afoot to erect a major powerline through the park.

Photography resource link: For inspiration, the photograph of Nancy Rotenberg and Michael Lustbader at Natural Tapestries. Much to admire in the photo galleries! Not only did I find the nature galleries wonderful, but I also enjoyed this series of photographs of San Miguel de Allende in Mexico.

If you visit the Oregon Coast near Florence, it is worth the brief amount of time away from the dunes and ocean to step into the Darlingtonia State Natural Site (map). A short boardwalk trail affords the opportunity to observe this species en masse. This photograph was taken in March of last year, a couple months prior to the flowering season.

Like the related Sarracenia purpurea, cobra lily or California pitcher plant is an insectivorous plant. As aptly explained in the Wikipedia entry on Darlingtonia californica, it does have a few qualities that distinguish it from Sarracenia (and the third genus in the family, Heliamphora). First, instead of capturing rainwater, it regulates the water level in its trap through its roots. Second, the species does not produce digestive enzymes to break down the captured insects, but instead relies on symbiotic bacteria to act in a similar way. A third difference is the structure of the modified leaf; its curved, nearly-enclosed trap is seemingly the most effective in preventing the insect from leaving, with a number of “false exits” (transluscent leaf tissue) befuddling and tiring the insect as it tries to escape.

If you're seeking more photographs of this plant, I highly recommend Makoto Honda's Insectivorous Plants in the Wilderness photo gallery page for Darlingtonia californica.

As a botanical aside, the genus was named after the botanist Darlington by the botanist Torrey, who himself had a genus named after him: Torreya, which is prominently mentioned in the linked-to article in this weblog entry from yesterday.

A different sort of thank you to lead off today's BPotD: thank you to those BPotD readers who attended yesterday's lecture. I hope you enjoyed it as much as I enjoyed sharing.

Erinacea anthyllis, or hedgehog broom, was previously featured on Botany Photo of the Day in Nov. 2005: Erinacea anthyllis. Its distribution in the western Mediterranean region includes populations in Parque Nacional Sierra Nevada (Sierra Nevada National Park) near Granada, Spain.

Another thank you to Andreas of Bogotá (aka Quimbaya@Flickr) for sharing images of plants from Colombia (original). This photograph is part of a set that Andreas has assembled on Cerro de Usaquén. Much appreciated!

I had a difficult time discovering any information about this genus of plants until I broadened my search a little bit and learned that the genus Espeletiopsis (and 7 other related genera) were all once lumped under the genus name Espeletia. That led to discovering this site by Dr. Jason Rauscher, The Espeletia Page. Dr. Rauscher has written a brilliant introduction to this fascinating group of plants. Some tidbits: most of these plants grow in tropical montane regions with the growth form of a giant rosette. The height of plants in these genera range from small rosettes measuring only 5 cm high to the tallest plants in the local landscape at over 5 m. Photographs of some of these giant relatives of today's Espeletiopsis corymbosa can also be found on Dr. Rauscher's site in this gallery of images.

Eric in SF@Flickr has kindly shared today's photograph with us (original image posted ~ a year ago on the BPotD Flickr Group Pool). Thank you once again, Eric.

California buckeye is endemic to the state. Its poisonous properties were recognized and utilized by the First Nations of the region, who ground the seeds into flour and then used the flour as a fish poison (ref: Jepson Manual and expanded in the Wikipedia entry on Aesculus californica).

Henry W. Coe State Park shares a series of photographs of California buckeye on its web site, if you're keen to see the plant from other perspectives and in detail.

On a different note, if you live in the Seattle area, you might like to attend my lecture on “Beauty and the Botanist” at 1pm tomorrow at the Centre for Urban Horticulture (3501 NE 41st St.), hosted by the Northwest Perennial Alliance. Cost is $5 if you're not an NPA member.

Botany / art resource link: Discovered via Pruned weblog, Wood Anatomy of Central European Species shows the beauty of wood at the cellular level. Take a look at Larix decidua as a fine example of what's available in the list of species.

Another African plant today, this time courtesy of sky_view@Flickr from California (original | BPotD Flickr Group Pool). Do have a look at sky_view's other stellar images of flowers! Thank you for sharing.

“Lachenalia liliflora is one of the most beautiful and most endangered bulbs on the planet.” states Adam Harrower of Kirstenbosch Botanical Garden in this thorough article on the species. Along with biological details about the plant, Harrower relates a sad story of the destruction of one of the three known remaining wild populations; it involves a bulldozer and a new housing development. Though his story mentions that half of the plants had survived, more recent accounts I've read suggest that all of the plants have since been wiped out. The Wine Estate De Grendel and the Tygerberg Nature Reserve near Capetown now host the two remaining populations.

This species has also been the subject of artist illustrations. I'm fairly certain one of the first appeared in Icones Plantarum Rarorium (published between 1781 and 1793), available online thanks to the Missouri Botanical Garden's Rare Books initiative here. Jean Emmons, a member of the Brooklyn Botanic Garden's Florilegium Society, likely has one of the most recent illustrations: Lachenalia liliflora (2006).

Thank you to Brent aka foliosus@Flickr from Portland, Oregon for sharing today's photograph with us (original) via the BPotD Flickr Group Pool. Check out Brent's web site for an appealing mixture of plants and web design.

A close-up shot of Zantedeschia aethiopica, or arum lily, was previously featured on BPotD. It's accompanied by a good set of links about the plant, so I won't pursue that again today.

However, a little bit of botanical history might be intriguing. Zantedeschia is named after the physician Giovanni Zantedeschi, by the physician and botanist Kurt Sprengel. This pattern of medicine and botany intertwined is longstanding, which makes sense considering the original medicines were directly derived from plants (and, of course, animals).

As another example, the University of Uppsala in 1692 had a professorial chair in “medicine and botany”. This chair was eventually occupied by Linnaeus, after a swap with Rosén for the chair in “practical medicine” (this meant Linnaeus was now in charge of the botanical garden, chemistry and botany while Rosén headed the university academic hospital, human anatomy, human physiology, etc.).

Finally, here's a search on Google for both “physician and botanist” and “botanist and physician”.

Gardening resource link: Kingsbrae Garden in New Brunswick has started up the Kingsbrae Garden Weblog, so you can follow along on how their garden progresses. Discovered via bloomingwriter (jodi DeLong), who posted a comment to yesterday's photos (her take on Kingsbrae is here).