Thank you to serialplantfetishist@Flickr of Berkeley, California for sharing today's photograph (original | BPotD Flickr Group Pool). Much appreciated!

A few days ago, Brent Hine asked me to name my favourite herbaceous plant. After hemming and hawing a bit and giving the standard answer of “What's in bloom today?”, I settled on Puya as a provisional reply, at least in part because of the colours and structure. That's not to say I know a lot about them. I've only encountered a few in person, but I do know I want to see more.

For this particular species, the scientific name and the English common name seem to be the same. As mirabilis means “wonderful”, it would perhaps seem strange to call it the wonderful puya (especially when so many others are wonderful, too!). Native to Bolivia and Argentina, Puya mirabilis is one of over one hundred and fifty species within the genus. Puya species can be found throughout the highlands of South America and it is the Mapudungun vernacular name for this group of plants that lends the genus its scientific name.

As puyas go, Puya mirabilis is a short plant, reaching at most 2m (6 ft) in height. The tallest member of the Bromeliaceae, Puya raimondii, can exceed heights of 13m (43 ft), while many other members of the genus exceed 3 to 4m.

xavierraynaudphoto@Flickr is the photographer behind today's image (original image via BPotD Flickr Group Pool). Thank you!

I've titled this plant with a tentative name, as it is my own identification; with 80 species in the genus, some cultivars and a number of unnamed hybrids, I can't say for certain whether this is indeed what it is. It does seem to have the qualities of Curcuma alismatifolia, including (I'm guessing) its use as a cut flower.

If my identification is correct, then the common name for this plant is Siam tulip or summer tulip (though, as is often the case with common names, it is not a tulip, but rather a ginger relative). In the wild, some of the densest populations of this species can be found in Pa Hin Ngam National Park of north-central Thailand. The range of the species extends southward from Thailand into Cambodia and northward to Burma and Laos.

The first collection of this species by Western explorers occurred in 1859, when the British explorer Robert Hermann Schomburgk collected it in Thailand (while he was serving as the British Consul-General). It was next collected in 1875 by Parisian botanist Godefroy–Lebeuf (at the age of 23) from Cambodia. The species was finally scientifically named forty-four years after Schomburgk first collected it by the French botanist, Gagnepain.

Thank you to Douglas Justice for both today's photograph and accompanying written entry. – Daniel.

Euonymus planipes is a deciduous shrub or small tree native to Korea, northern Japan and eastern Siberia. According to the USDA Germplasm Resources Information Network (GRIN) website, one of the common names is “dingle dangle tree.” Sure it is. The name planipes means “flat stalk,” referring to the flattened petioles of this species. Euonymus species are often difficult to differentiate; many have similar looking leaves and a number share the flattened petiole feature, for example. Identification of Euonymus species can be problematic without careful examination of the overwintering buds and particularly, the ripened (i.e., open) fruit. Features of the fruit that are necessary for many identifications include the shape of the capsule and the colour and vestiture of the seeds. The pure white seeds of E. planipes show an incomplete covering by a fleshy orange aril (all Euonymus species have arillate seeds). The aril is rich in fats and is a reward for birds that disperse these seeds. Note that each seed hangs by its funiculus from the placenta of the fruit wall.

Euonymus are generally excellent garden plants (where they aren’t invasive weeds), but it is worth noting that all parts are considered to be poisonous. The Canadian Biodiversity Information Facility reports that two horses were fatally poisoned after ingesting shoots of European spindle (E. europaeus) and that children are attracted to the fruits of that species and have become “quite ill” after ingesting seeds. The toxic compounds present include a digitalis-like cardiotoxin (evomonoside) and several alkaloids. Birds evidently get around any toxicity by quickly passing them. Most American references rate Euonymus spp. as Class 2 (minor toxicity) plants; i.e., “ingestion of these plants may cause minor illnesses such as vomiting or diarrhea. If ingested, call the Poison Control Center or your doctor.”

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Thank you to Natalie G. of Spain for submitting today's photograph from the countryside near her home.

Blue passionflower or common passionflower is native to southeastern South America. Similar to yesterday's plant, though, it can now be found cultivated in many tropical and subtropical regions of the world (but also more than a few warm temperate areas as well). The Plants for a Future database provides more information, including cultivation and propagation methods.

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Thanks to “Shyzaboy@UBC BG Forums” of Troutville, Virginia for today's photograph from Panama. Images from the tropics are very welcome!

Although native to northeast Brazil, the cashew is now cultivated in tropical areas throughout the world. Illustrated in today's photograph are both the double-shelled kidney-shaped fruit containing the cashew nut and the apple-like pseudofruit (cashew apple). Both the cashew nut and cashew apple are edible, but extra effort is required to extract the cashew nut; its double-shell contains urushiol, the same oil found in poison ivy.

Read more about cashew via Wikipedia and Morton's Fruits of Warm Climates.

Today's contribution is from Flower of the Desert@Flickr of (if I'm correct) Arizona, USA (original image via BPotD Flickr Group Pool). Many thanks!

The flowers of Arizona queen of the night (aka night blooming cereus) last one night before fading away. Perhaps more amazing, the individuals within a population of plants bloom synchronously on less than 5 nights per year and the flowers are self-incompatible. How, then, do the plants get pollinated given the narrow window of time? A few scenarios are possible. Perhaps a generalist pollinator species could visit the flowers, but presumably a generalist would have a lot to choose from and it would be quite hit-and-miss that they'd visit these flowers often enough (and I suspect most generalists are not active at night). Perhaps a specialist insectoid pollinator species emerges at the same time as Peniocereus blooms. That hasn't been shown to be the case.

The question of the floral biology of Peniocereus greggii was examined by Dr. Robert Raguso and a team of researchers (see Raguso, RA et al.. 2003. Trumpet Flowers of the Sonoran Desert: Floral Biology of Peniocereus Cacti and Sacred Datura. International Journal of Plant Sciences. 164:877-892). The researchers discovered that Peniocereus greggii and the often-growing-nearby and spring-to-fall blooming Datura wrightii (see a related species) shared a few things in common, including pollinators (hawk moths at dusk, bees in the morning), pollination reward, (lack of) UV reflectance and a few benzenoid compounds (components of floral scent). In other words, the pollination of Peniocereus greggii seems to rely on the presence of Datura wrightii to sustain a population of shared hawk moth pollinators that is both specialist enough and in sufficient numbers to visit its flowers when it is in bloom (as for the bees, recall the suggestion that generalists visit many plants and the chances of cross-pollination are reduced).

Read a factsheet about Peniocereus greggii via New Mexico Rare Plants. Two other photographs are available to be viewed via Wildflowers of Tucson, Arizona. Lastly, a legendary tale and a curatorial anecdote offer two different perspectives on the plant via the site of Tohono Chul Park.

Thanks again to David Tarrant for today's photograph from Mexico.

Douglas Justice and I were discussing the numbers cited about the Asteraceae in yesterday's entry after I mentioned to him that many of the plants that David photographs in Mexico have little or no presence online. Today's photograph is another example; of the few search engine results, many only have scant information on this Mexican endemic (e.g., checklists or name databases). Fortunately, Mexico's Conabio provides a detailed factsheet and comprehensive photographs, otherwise this scanned text from the “Trees and Shrubs of Mexico” is some of the best information available online (via Botanicus). To be fair, the original description of the plant by de Cavanilles is available online in this PDF from the University of Valencia in Spain (pages 18 and 83, by the way), but it isn't exactly what I would call accessible. It truly helps one begin to understand the scope of projects like the Global Biodiversity Information Facility, where huge efforts are required to construct and maintain only the barest subset of all published information about plants. The Encyclopedia of Life project will, one day, provide “an online reference source and database for every one of the 1.8 million species that are named and known on this planet, as well as all those later discovered and described”. Let's all keep our fingers crossed and support this ambitious venture.

Environment resource link: EarthPortal is a “comprehensive resource for timely, objective, science-based information about the environment. It is a means for the global scientific community to come together to produce the first free, expert-driven, massively scaleable information resource on the environment, and to engage civil society in a public dialogue on the role of environmental issues in human affairs.”. See “Conservation and Management of Rare Plant Species” and “Global Marine Biodiversity Trends” for two stellar examples.

Thanks again to Brent aka foliosus@Flickr from Portland, Oregon for contributing today's photograph (original | BPotD Flickr Group Pool). Appreciated as always!

Of the 21 000+ species in the Asteraceae, the genus Erigeron contains somewhere between two hundred species (source: Wikipedia) and nearly four hundred (source: Jepson Manual). It is well represented; with ~1300 genera, the average number of species/genus in the family is roughly 16 (as an aside, this prompts the question: what are the genera in the Asteraceae with the most species?). With such diversity, it comes as no surprise that the Asteraceae are the spiders of the plant world; with a cosmopolitan distribution, you'd find it difficult to take a short walk anywhere without encountering one, except for central Greenland, Antarctica and places devoid of plant life.

The species Erigeron peregrinus is found in western North America and eastern Asia, though the particular subspecies illustrated today does not occur in Asia or northern Canada. Paul Slichter shares a description and more photographs of subalpine daisy or foreign erigeron via his site on fleabanes found east of the Cascade Mountain crest.

Butterfly gladiolus or goldblotch gladiolus is one of the approximately one hundred and sixty species of gladiolus endemic to South Africa. Unlike the genus Watsonia (featured on BPotD a couple days ago), the genus Gladiolus extends beyond the borders of South Africa; it can be found throughout much of sub-Saharan Africa and parts of Eurasia, though its centre of diversity remains in South Africa.

Within the globally widespread family Iridaceae, Gladiolus belongs to the Old World subfamily Crocoideae, along with Watsonia, Crocosmia, Dierama, Crocus and Babiana. Iridaceous plants not belonging to the Crocoideae featured on BPotD to-date include Cypella, Iris, Olsynium, Sisyrinchium and Diplarrena, all belonging to the subfamily Iridoideae.

The Angiosperm Phylogeny Group goes into taxonomic detail on the Iridaceae and its subfamilies.

Paghat writes about Gladiolus papilio from a horticultural perspective.

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

Thank you to roselea@Flickr from British Columbia for sharing today's photograph (original titled “Blue” via UBCBG BPotD Flickr Pool). Aptly named!

Although native to the Middle East, the range of borage has expanded throughout the Mediterranean region and into central and eastern Europe, along with introduction to other regions of the world. Borage is considered a neglected horticultural crop by Nuez and Bermejo; the authors point out its relatively scant cultivation as a crop, despite its many food uses. Gernot Katzer adds more details about the culinary uses of Borago officinalis on his valuable Spice Pages site.

Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel

All fifty or so species of Watsonia are endemic to South Africa, though some have naturalized elsewhere after introduction by humans. This particular species is not well-known in cultivation. It is named in honour of Henry George Fourcade, surveyor and botanist.

This is the backlit leaf of a giant sunflower growing in the Food Garden here at UBC Botanical Garden. Despite the general cloudiness of this past summer, a few of these plants have easily exceeded 3.5m (~12ft) in height.

What is immediately obvious is the network of veins in the leaf. While the veins are essential for nutrient and water transportation, in many leaves they also help to provide a structural skeleton. Each vein consists of xylem (water-conducting) tissue and phloem (sap-conducting) tissue surrounded by a protective wrapping of structural tissues, including collenchyma. In the spaces between the veins (and bounded by the upper and lower epidermi of the leaves) is the tissue called parenchyma. In leaves, parenchyma cells are packed with chloroplasts, the organelles that are responsible for photosynthesis. It should be noted that other parenchyma cells may have different functions elsewhere in the plant, such as storage or secretion. This is why the chloroplast-laden parenchyma of leaves is sometimes referred to as chlorenchyma, so as to better reflect the specific purpose of this tissue.

I don't mention photosynthesis often enough on BPotD, considering the fact that nearly all complex life on Earth depends on this process in one way or another. The evolution of photosynthesis approximately 3.5 billion years ago and subsequent alteration (with some lag time) of the Earth's atmosphere to the present day concentration of oxygen in the air permitted the evolution of complex life.

Is this Cucurbita moschata 'Tromboncino' or Cucurbita moschata 'Trompo d'Albenga'? The more I researched the name, the more confused I became.

The seeds for this plant growing in the UBC Food Garden were purchased under the name 'Tromboncino' squash. My first search for more information led me to this plant review page on the Dave's Garden site, where 'Tromboncino' is listed as an alternate name for the preferred 'Trompo d'Albenga'. The Kokopelli Seed Foundation repeats this assertion in its photo gallery of squash cultivars. However, things start to get muddied in the Kemper Center for Home Gardening photo gallery of 100+ squash cultivars – the name 'Tromboncino' is used; perhaps they didn't research the name to verify it? Or perhaps they did: the Master Gardeners of Santa Clara County Online have a photo gallery of the squashes growing in McClellan Ranch in 2003, and 'Tromboncino' and 'Trompo d'Albenga' are distinguished as separate cultivars!

My final step for an easy answer was to consult whatever squash cultivar databases I could find online, and I came up empty. This comprehensive listing of squash cultivars excludes both names, unfortunately.

For general information on squashes, Purdue University's New Crop Guide has an extensive factsheet on cucurbits.

Yesterday evening was only the fourth time since the beginning of April when I've had the opportunity to photograph in the garden — a somewhat worrying statistic for me. I've been fortunate enough to be able to travel this summer, but not being out in the garden often enough to observe the seasonal progression has been a bit disappointing.

Stemless carline thistle or dwarf carline thistle is native to the mountainous areas of central and southern Europe. The epithet acaulis means “without a stem”, but as you can clearly see in this photograph, this plant certainly has one. That suggests that this is either subspecies simplex (a stemmed subspecies of the plant) or a garden hybrid with Carlina acaulis subsp. simplex as part of the genetic mix.

In addition to the usual edibility (a globe artichoke substitute!) and medicinal use information often detailed in the Plants for a Future database, the entry on Carlina acaulis lists another use: weather forecasting. PFAF cites a reference that suggests the dried flowers of Carlina acaulis can be used to measure humidity, whereas the mature flowers of a plant will close prior to a rainfall. I'll have to keep a closer eye on them to verify the latter...

More information can be found on Wikipedia, including a photograph of a plant with a sessile (acauline) flower. A botanical illustration of Carlina acaulis is available via Thomé's Flora von Deutschland.

Thanks to David Tarrant are once again in order for today's photograph from Mexico. Appreciated as always, David.

Despite a specific epithet (roseus) that translates to “pink”, the common name often used in the USA for this species is white rocklettuce. Pink dandelion is also sometimes used, as is white dandelion. Curiously, it seems the plants growing in the northern part of its range (south-central USA) tend to have little pink colouration (e.g., these photographs from the Lady Bird Johnson Wildflower Center), while those growing in the southern part of its range (central Mexico) are quite pink (e.g., today's photograph and this other photograph from Mexico).