Returning once again to South America this week, with an entry that Alexis wrote this past summer. As an aside, I've hired a new work-study student thanks to your donations (which directly support these hires). I'll introduce her when her first entry is ready to be posted.

Alexis writes:

Dave Winkel shares this photo from Chile's Torres del Paine National Park. Thanks, Dave! Calceolaria uniflora, also known as Calceolaria darwinii, is native only to Argentina and Chile.

A study of plants of this species in southern Patagonia suggests the existence of two subspecies of Calceolaria uniflora that differ in two flower features: the appearance of the instep (in the photo, the splotchy lower lip), and the colour of the throat (the somewhat striated middle portion). The instep displayed two phenotypes within the study area. A uniformly dark red instep was called uniform and a patchier instep with more yellow and orange was called maculate. Throat colour varied from dark red to orange to yellow, though no discrete colour categories could be established.

The study found that instep type correlated with the geographical longitudinal position of the flower populations; more specifically, populations in the western forest and grassland were uniform, populations in the eastern steppe were maculate, and intermediate areas had mixed populations with individuals of both types. The throat colour variable, however, showed a latitudinal pattern, with individuals becoming more orange and less yellow from north to south.

The authors suggest several explanations for these morphological variations within the species. It is possible that different species of pollinators (such as Thinocorus rumicivorus) are attracted to different flower types, and that these variations are an adaptation designed to attract the appropriate pollinators, though there is no evidence yet to support this hypothesis. Different climatic conditions could also play a role; the study observed that flowers tended to be redder in the south, containing more anthocyanin, a feature that may help shield the plant against the cold weather and UV radiation prevalent in that region. Additionally, geographic barriers, isolation, and gene flow could have all contributed in developing the two observed subspecies of Calceolaria uniflora, and further studies may present more evidence.

Another new species from Brazil today! BPotD reader Gary Zamzow alerted me to the recently-described Spigelia genuflexa, published (as of yesterday) in the peer-reviewed, open-access journal PhytoKeys: Popovkin AV, Mathews KG, Santos JCM, Molina MC, Struwe L (2011). Spigelia genuflexa (Loganiaceae), a new geocarpic species from the Atlantic forest of northeastern Bahia, Brazil. PhytoKeys 6:47-65. doi: 10.3897/phytokeys.6.1654.app4 .

First discovered by José Carlos Mendes Santos, a handyman in rural northeastern Bahia of Brazil, these diminutive plants on the property of amateur botanist Alex Popovkin were photographed and collected by Mr. Popovkin over the course of the past couple years. All of today's photographs are courtesy of Alex, via Flickr (his photostream: Alex Popovkin, Bahia, Brazil@Flickr). Original images for today's posting are here, here, and here, and these are part of a much larger set of images by Alex: Spigelia genuflexa.

In the course of trying to determine what species this might be, Alex communicated with taxonomic experts from around the world. The evidence seemed to suggest this was perhaps a new species. With the aid of taxonomists from Universidad Rey Juan Carlos and Rutgers University, the work in establishing it as a new species (through comparisons with previously described species, including phylogenetic analyses), Spigelia genuflexa was recognized and published.

Spigelia genuflexa is unique among the known members of its genus for being geocarpic: (from the article) "During fruit maturation, the basal infructescences bend down towards the ground, depositing the fruit on the surface (and burying it in soft kinds of ground cover, e.g., moss), whereas the upper ones do so slightly but noticeably." I can recall only one other species with this property previously featured on Botany Photo of the Day, Pseudotrillium rivale.

Only a few small populations are known for this species, all restricted to the sandy leaf litter- or moss-covered soils of the Atlantic tabuleiro forest of Bahia. Growing to 25cm (though initially discovered with plants only 3cm tall), it is a short-lived annual.

To read the press release surrounding the discovery, see "Amateur botanists in Brazil discover a genuflexing plant".

Today, a few photographs of this persisting bloomer located at the front entrance to UBC Botanical Garden. Ipomoea purpurea 'Star of Yelta' is an introduction from Thompson & Morgan Seeds. T & M describe this cultivar as having half-hardy annual seeds, meaning that in cool temperate climates, it can be sown early in the season once the danger of frost has passed (but before the soil has warmed). In the maritime climate here at UBC, 'Star of Yelta' has persisted from year to year in areas of bare soil without additional seed-sowing by the horticulturists. Given that the parent species has been declared a noxious weed in some jurisdictions (though none in our region) and has naturalized in some pantropical areas, the staff here are monitoring the behaviour of this cultivar. Despite its beauty, it may have to be eradicated if it shows additional indications of potential weediness in our climate.

Today's photographs are courtesy of Dr. Marcelo Trovó, a plant systematist in the Instituto de Biociências at the Universidade de São Paulo in Brazil. I became aware of this species after browsing through the latest issue of Systematic Botany where Dr. Trovó and a colleague, Paulo Sano, published a paper entitled, "Five New and Narrowly Distributed Species of Paepalanthus Section Diphyomene (Eriocaulaceae) from Central Brazil" (Systematic Botany (2011), 36(3):610-620, doi: 10.1600/036364411X583600). Dr. Trovó generously shared his photographs of this newly-described species (by him) after I sent a request to him yesterday. Thank you, Dr. Trovó!

Eriocaulaceae is typically a pantropical family, though some representatives grow in temperate areas. Of the 1200 or so species in the family, approximately 550 are in Paepalanthus, making it the most biodiverse extant group. I tried to sleuth the meaning of the name Paepalanthus, and while -anthus is easy ("flower"), Paepal- is not so readily found in my available resources. Assuming that the name comes from the Greek word Paipale as some suggest, then I think Paepalanthus means "meal-flowered" or "particle-flowered" (Paipale is somehow related to pollen and flour meal). For the etymology of the epithet of today's species, stellatus, I'll simply quote Trovó's paper "...refers to the numerous white capitula arranged in an umbellate inflorescence, resembling a star-like constellation".

Paepalanthus stellatus is found only in open savannas dominated by grass in small areas of Goiás. As photographed here, it can be found in dense populations of over 100 individuals, but as it is known from very few locations in a small geographic area, it can be considered critically endangered (PDF) according to IUCN Red List criteria.

Growing to 85cm tall, from the basal rosette of leaves (typically persistent) emerges a reproductive axis. At the top of the axis, anywhere from 40-400+ scapes from 13-25cm long emerge, each tipped with an obconic capitulum. The capitula each contain approximately 55 flowers (about 50 of these pollen-producing, and 5 pistillate). The staminate, or pollen-producing, flowers are mature in March, while pistillate flowers reach full maturity in April.

A photograph from what seems like many years ago now (2006), during a late March visit to the Hummingbird Aviary at the Arizona-Sonora Desert Museum. I'm hoping I've identified this correctly to Lonicera arizonica--another possibility is Lonicera sempervirens, but I believe the inside surface of the tubular flower is typically yellowish for that species.

There isn't much information online about Lonicera arizonica, but an excellent resource is the Arizona Biomes site, where they list the species as being a common shrub of Arizona's subalpine conifer forest. They also include a factsheet about Lonicera arizonica with descriptions of its ecology, uses and identification.

Additional photographs of Lonicera arizonica are available from the Southwest Environmental Information Network.

An entry written by Alexis:

Thank you to Eric Hunt (Eric in SF@Flickr) for sharing his photo of bo tree (also called sacred fig or peepal) leaves via the Botany Photo of the Day Flickr Pool.

Native to India, Indochina and nearby areas, Ficus religiosa (PDF) is a large tree with spreading branches, reaching about 20m in height. The tree loses its leaves in January, and when the new ones emerge in March and April, they are pink, reddish, or bronze and eventually darken to green. The distinctive tails or "drip-tips" may serve to draw rainwater away from the leaves. The species is a member of a group called the strangler figs. Young plants begin life as an epiphyte on another tree where they are sustained by rainfall and air. As the roots develop and reach the forest floor, they surround and "strangle" (sometimes literally) the tree that the plant is growing on.

The name religiosa refers to the significance this species has in both Buddhism and Hinduism. It is said that Gautam Buddha meditated and achieved enlightenment under a particular Ficus religiosa tree in Bodh Gaya, India, which is now known as the Bodhi Tree. Although the original tree is gone, in 288 BC, a cutting was taken from it and planted in a temple in Anuradhapura, Sri Lanka, and this sacred fig is still alive today. For Hindus, the species is also sacred and regarded as the female counterpart to the banyan tree; it is a sin to harm either of these kinds of trees.

Today is Alexis's last day working on Botany Photo of the Day, though she's assembled a number of entries I'll be using in the upcoming weeks. Alexis writes:

Drew Avery (Drew Avery@Flickr) took these photos (image 1 | image 2) in the Copenhagen Botanical Garden in Denmark. Thank you, Drew!

Echinops sphaerocephalus, growing 50-200cm tall, belongs to the largest family of vascular plants, Asteraceae. A single inflorescence (3-6cm in diameter) is comprised of many tiny florets, each "surrounded by spiny involucral bracts" (Polunin's Flowers of Europe (1969)). The species is native to Asia and Europe, but is also cultivated elsewhere. It typically blooms from June to September in the northern hemisphere.

The genus name comes from the Greek echinos, meaning "hedgehog", and opis, meaning "appearance", likely referring to the inflorescence or the bristly leaves, which have spiny margins. Sphaerocephalus is also derived from Greek and means "sphere- or round-headed". The species is probably better known as great globe thistle or pale globe thistle. Echinops sphaerocephalus usually occurs in rocky, dry areas and disturbed sites.

Alexis authored today's entry:

Today's photo of a young rhubarb plant is via Wikimedia Commons and was taken by Andrew aka polandeze@Flickr (original Flickr page). Thanks, Andrew!

The use of rhubarb can be traced back as early as 2700 BC in China, when the dried roots of Rheum officinale and Rheum palmatum were used as a laxative. The species Rheum rhabarbarum, native to Mongolia and surrounding regions, was first cultivated in England in 1573. Though initially cultivated for its medicinal properties, by the eighteenth century it had been subject to (additional?) hybridization, and the hybrid's leaf stalks became a desirable food. All parts of the plant contain oxalic acid, and the leaves themselves are poisonous to people and animals if ingested in large amounts.

There are many cultivars of rhubarb, differing from each other by properties such as colour, size, and acidity level. Phillips & Rix's Vegetables (1993) served as a valuable reference for this entry.

Today's photograph was from the third week of May this past year, from a sidetrip to the Gasquet Darlingtonia Botanical Trail in California (not to be confused with the one near Florence, Oregon). I had hoped to see a particular species of Trillium there, but struck out again. Still, the wedgeleaf violets (cuneate = "like a wedge") were out and in a convenient place to photograph, so I spent some time with them.

Viola cuneata is found only in northwestern California and southwestern Oregon. It is often associated with serpentine soils (a serpentinophyte), but it is not exclusive to these difficult growing environments. Studies have shown that it is able to accumulate high amounts of nickel in its tissues (up to 664 µg/g) without any apparent adverse effects (see Reeves, RD et al. 1983. Accumulation of Nickel and Zinc by Western North American Genera Containing Serpentine-Tolerant Species Am. J. Bot.. 70(9):1297-1303). Other nickel-tolerant species, such as Thlaspi montanum are hyperaccumulators of nickel (>1000 µg/g), and it has been shown that this is effective in producing tissue toxic enough to kill feeding insects (see Boyd, RS and SN Martens. 2004. Nickel Hyperaccumulated by Thlaspi montanum var. montanum Is Acutely Toxic to an Insect Herbivore. Oikos. 70(1):21-25).

Additional photographs of wedgeleaf violet are available from the Oregon Flora Image Project: Viola cuneata and Calphotos: Viola cuneata.

Today's entry was authored by Alexis:

Thank you to Tony Foster (Tonyfoster@Flickr) from the Botany Photo of the Day Flickr Pool (image) and Kahuroa at Wikimedia Commons (image) for their photographs of today's species. Cordyline australis produces sweet-scented white flowers that bloom in October to December in the southern hemisphere. The flowers attract flies, which carry out pollination.

This species, also known as cabbage tree, is endemic to New Zealand. It is a common tree in New Zealand, found in a variety of habitats like "swamps, sand dunes, coastal scrub and forest margins, river banks and dry hillsides" (Newhook's Our Trees: A New Zealand Guide (1982)). It grows up to about 20m tall. Parts of the tree can be eaten and are rich in carbohydrates. Historically, Maoris made a porridge-type food out of the sun-dried pith and roots of young trees, and also used the trees as sources of fibre and medicine. Early European settlers found uses for Cordyline australis as well; they fashioned chimneys from the hollowed out trunks, which are fire-resistant, and made beer from the roots.

In 1987, Cordyline australis individuals of the North Island of New Zealand fell victim to a mysterious disease that caused sudden wilting, the falling off of leaves, and death within 3 to 12 months. This condition, simply known as "sudden decline", was later discovered to be caused by a phytoplasma parasite transmitted via an introduced sap-sucking insect.

An entry written by Alexis today:

Thank you to forum member davallia for posting these photographs of Aechmea gamosepala on the BPotD Submissions Forum. These were taken at the Royal Botanic Gardens in Melbourne, Australia.

Aechmea is a genus in the Bromeliaceae that has over 200 species. Its name derives from the Greek word aichme, meaning "spear".

The common name for this Brazil native is matchstick plant, and its flowers do resemble its namesake. Bromeliads are known for their showy bracts, and in the case of Aechmea gamosepala, they are pink in colour, while the petals are purple. Though the flowers are relatively short-lived, they bloom several times annually, making it a desirable ornamental. Typical of Bromeliaceae, the leaves are arranged in a rosette. Aechmea gamosepala grows to about 30cm in height, and can be epiphytic (sometimes growing on trees).

The hike through the wildflower meadows of Trophy Mountain in Wells Gray Provincial Park has been called A Hike to Remember. That's indeed the case, as it is one of the best mass displays of wildflowers in British Columbia. In typical years, it peaks in early August, but thanks to the heavy snows and cool spring locally, it was delayed a couple weeks. Earlier in the year, about a month preceding this swath of colours, the hillsides are covered in yellow from the Erythronium grandiflorum (which I've not seen).

By the way, for those who don't often read comments from previous entries, you may have missed that you can click on the photographs on BPotD, and then sometimes enlarge them again (the square grey box in the upper right corner of the image).

Alexis authored today's entry:

Van Swearingen (Van in LA@Flickr) took these pictures at the Los Angeles County Arboretum and shared them in the Botany Photo of the Day Flickr Pool (photo 1 | photo 2 | photo 3). Thanks, Van!

Ceiba insignis, sometimes still called by the synonym Chorisia insignis, is a deciduous tree native to the dry forests of western South America. Commonly, it is known as the white floss-silk tree, chorry, or white dragon. Oftentimes, the tree fattens significantly towards the base, a fact that likely caused the species to garner the nickname South American bottle tree. The sharp prickles seen on the trunk can become over an inch wide as the tree grows and its trunk widens. When young, the bark is green but as the tree ages it turns grey. When fruits (from Trees of Miami) reach maturity, they split open to reveal seeds that are surrounded by silky white hairs. These have been used as a stuffing for pillows and life vests.

This species is quite similar to Ceiba speciosa, and they may be difficult to differentiate when not in flower. Usually, Ceiba insignis has white flowers with golden throats and Ceiba speciosa's flowers are pink with white throats. However, variation does occur and sometimes Ceiba speciosa may produce paler flowers or Ceiba insignis may have slightly pink flowers (ref: Krishen's Trees of Delhi (2006)).

Today's entry was written by Alexis.

Scott Zona (aka scott.zona@Flickr) took this photograph at the Wertheim Conservatory & Greenhouse at Miami's Florida International University. Thank you for sharing, Scott!

Stapelia flavopurpurea is a small succulent species native to South Africa and Namibia, usually found growing beneath bushes and in stony areas. It is associated with calcrete.

Stapeliads are also known as carrion flowers because they often give off unpleasant odours (often like rotting flesh) that attract flies, which act as pollinators. Stapelia flavopurpurea is one of the few Stapelia species that do not have a stinky smell. On the contrary, they may give off a pleasant scent; the scent of the lighter-coloured flowers has been compared to that of honey or marzipan. The flowers of this species are also highly variable in appearance and exhibit an array of colours. The flower lobes can vary from brown to red, green or yellow. The centre of the flower is typically white, but covered in hairs that may be white or purple. Lastly, the corona is white to red-purple with a yellow-tinged base (ref: Bruyns' Stapeliads of Southern Africa and Madagascar (2005).

A photograph from mid-May that I should have perhaps waited to share during some dreary winter day, but perhaps it is dreary and wintry for BPotD readers from the southern hemisphere today.

I hope I've identified this correctly as Eschscholzia caespitosa, or tufted poppy. One of the main differences between Eschscholzia caespitosa and Eschscholzia californica is that the latter has a rimmed receptable, which is absent in the plant in today's photograph.

Eschscholzia caespitosa is native to chaparral plant communities from Oregon to Baja California.