Today's photo is of Equisetum arvense, also known as the field horsetail. This picture was taken by Hans Mohr (aka muscovite@Flickr) on May 19, 2013. Thank you Hans for the vibrant photo (submitted via the Botany Photo of the Day Flickr Pool)!

Equisetum arvense is a perennial species that is found across North America, Eurasia, Asia, and Greenland. Often, it grows along roadsides or riverbanks, or in fields and pastures. Though native, the field horsetail is considered a weedy species in British Columbia as it is poisonous to young horses and sheep when ingested.

Equisetum is derived from the Latin equus meaning "horse", and seta, "bristle", a reference to the resemblance of some species to the tails of horses. Field horsetail can propagate vegetatively from an underground rhizomatous stem. Fertile and vegetative aerial (aboveground) stems are hollow, except at the nodes. The shorter, brown fertile stems mature in early spring, shown in today's photograph. They are unbranched and terminate in a spore-bearing "cone". After spore dispersal, the fertile stems will wither and sterile stems grow. These vegetative counterparts with whorls of side shoots at the nodes are green and photosynthetic. The nodal leaves on the vegetative stems are dark brown, toothed, and form a papery sheath around the stalk.

Today's images (original 1 | original 2) of Melastoma malabathricum subsp. malabrathricum, commonly known as blue tongue or Malabar melastome or native lasiandra, were taken on April 17, 2011 by long-time BPotD contributor Andreas Lambrianides. Thank you for all of your wonderful photos and for today's pictures!

Melastoma malabathricum subsp. malabrathricum of the Melastomataceae is native to tropical Asia, Taiwan, parts of Australia, Mauritius and Seychelles. In Australia, typical habitats include roadsides, disturbed rain forest areas and other wet forests. The Flora of China's account seems to take a broader view of the species (Melastoma malabathricum), so the habitat includes more environments and the species distribution is wider.

The 3m tall stem of this shrub and its branches are covered in appressed scales. As shown in the photographs, the elliptical or ovate leaves are hairy and have a midrib with 2 to 3 longitudinal veins on either side. The terminal clusters of 3-7 flowers are purple-reddish in color with two leaf-like bracts at the base. The fruit is a densely hair-covered fleshy capsule. It dehisces to reveal a dark pulp with small orange seeds that are dispersed by birds.

According to Malay, Indian and Indonesian folk medicine, different parts of Melastoma malabrathicum are thought to have medicinal value for the treatment of a variety of ailments. There are also several prospective pharmacological uses, but in-depth scientific studies first must be completed to verify their potential (see: Joffry, SM., et al. 2011. Melastoma malabrathicum (L.) Smith ethnomedicinal uses, chemical constituents, and pharmacological properties: A review. Evid. Based Complement Alternat Med. 2012: 258434. doi:10.1155/2012/258434).

While walking through the David C. Lam Asian Garden, I found some visual appeal in the blossoms of Iris wilsonii swaying on stems of different heights. In the Garden today, they are highlighted by brief flashes of early-summer sunshine on an otherwise cloudy day.

Iris wilsonii is a Siberian iris (series Sibericae), native to China (note that Siberian in this case is a botanical-horticultural grouping). In China, it is found at mid- to high elevations in alpine meadows, streamsides and forest margins of the western part of the country. Iris wilsonii was introduced to Western cultivation by Ernest Henry Wilson around 1907. Irises in the Sibericae series can often be easily confused with each other, in part because they readily hybridize.

According to A Guide to the Species Irises: Their Identification and Cultivation, this herbaceous perennial grows to 60-70cm in height with grey-green leaves of about the same length as the hollow stem. The unbranched stem supports fragrant flowers in early summer, often of pale yellow with purple-brown stripes and spots. The fruit of this species is an ellipsoidal capsule that is borne on long pedicels.

Today's images of Libertia ixiodes original 1 | original 2) are from the top contributor of images to the Botany Photo of the Day Flickr Pool, the late James Gaither (aka J.G. in S.F.@Flickr). The pictures of both the flower and the immature fruit were taken on May 9th 2012, at UC Berkeley, California, USA. The photos that were uploaded by James are still greatly appreciated, including today's!

Libertia ixioides, or the mikoikoi or the New Zealand iris, is named after the 19th-century Belgian botanist, Marie-Anne Libert. Members of Libertia are generally thought to be of Gondwanan origin, with species occuring in New Zealand, Australia, New Guinea, and Andean South America. New Zealand is the centre of diversity. Libertia ixiodes is one of seven members of this genus endemic to New Zealand. It is widespread in the region though, as it is found on the North, South and Stewart Islands. Plants grow on ridges, cliffs, gullies, riverbanks and upland forests of coastal to montane ecosystems.

Libertia ixioides is a perennial herbaceous species that grows with branched rhizomes. Fans of highly-nerved leaves have pale red-green bases. Leaves tend to turn yellow when exposed to full sun. The inflorescence of white-tepaled flowers is a panicle. The ovary is larger than the perianth bud, and will mature into a barrel-shaped capsule that when ripe will be green to yellow to black in color. Spherical, bright orange seeds for dispersal are exposed when the capsule dehisces longitudinally.

This "Flounce Rock Grove" has been known since at least 1926, but it took another 27 years before the trees were identified as cypresses in 1953. Originally, they were thought to be junipers. The population at this grove is ca. 1000 individuals, give or take a few hundred, in a space of 0.8ha (2 acres). Some of the largest trees were felled by high winds, likely related to an adjacent clearcut and consequent loss of buffering capacity.

I should note that I'm not entirely certain whether Cupressus bakeri is the currently-accepted name; it is by some, whereas others (like the new Jepson Manual: Vascular Plants of California) use Hesperocyparis bakeri. The Gymnosperm Database summarizes the 21st-century papers on the subject of whether (most) North American Cupressus species should be separated out into Hesperocyparis. I decided to use Cupressus bakeri until the dust settles on the debate.

Additional photographs of Cupressus bakeri are available via Calphotos: Cupressus bakeri, including this 2009 photograph of the same group of trees as today's first photograph.

I was inspired to write about Yucca brevifolia by two of my friends with whom I went rock-climbing a couple weekends ago in Squamish, British Columbia. The pair of them had just returned from Joshua Tree National Park in southern California. They told me of this interesting species the park is named for, which they happened to see in bloom. Long-time Botany Photo of the Day contributor Damon Tighe@Flickr was also photographing this species in southern California at the time, and shared these images (original 1 | original 2) via the Botany Photo of the Day Flickr Pool. Thanks Damon!

Yucca brevifolia is endemic to the Mojave Desert of southern Nevada, southwestern Utah, southeastern California and western Arizona (it is also sometimes used to define the extent of the Mojave Desert, making it an indicator species as well). Joshua tree survives in low-precipitation areas with hot summers and cold winters (see climate data in the Mojave Desert link). Periods of cold temperatures provide the dormancy thought to prompt flowering in the spring for this tree-like shrub. The flowers bloom from March through May, and are pollinated exclusively by yucca moths in the genus Tegeticula, including Tegeticula synthetica and Tegeticula antithetica. (see: Godsoe W. et al. 2008. Coevolution and Divergence in the Joshua Tree/Yucca Moth Mutualism (PDF). The American Naturalist. 171(6): 826-823).

Joshua tree plants reach 5-20m in height, despite a relatively slow growth rate. The trunk is fibrous with a soft cork-like exterior, and may measure up to 1m in diameter. Older plants are branched and terminate with linear and waxy leaves clustered in rosettes. The egg-shaped flowers of this tree are bunched in panicles, while fruits are indehiscent capsules that become spongy and dry with age.

For previous BPotD write-ups on this species, see the entries from December 12, 2006 and June 16, 2008.

Broadleaf paperbark tree is native to eastern Australia, New Caledonia and Papua New Guinea. However, it has been introduced elsewhere, and has become invasive in some regions including Florida (where it is also known as the punk tree) and South Africa. In Australia, the species occurs in flatlands that are seasonally-inundated with water, water courses, and coastal swamps. Not only is it tolerant to the water-logging and salinity associated with some of those habitats, but it is also a fast grower adapted to fire; these properties are associated with resilience to disturbance and are part of the reason for its success as an invader.

With summer on its way in this hemisphere, I can't help but think of my favourite place to spend the season: Jasper, Alberta. I was fortunate enough to live there for a few years before moving to Vancouver, and I must say the beautiful wildflowers of the Canadian Rockies are at their finest in this National Park. I have chosen a reminder of my time in Jasper for today's Botany Photo of the Day, Rosa acicularis. This photo of the wild or prickly rose, the official flower of Alberta, was taken by Brian Van Snellenberg (aka brianv_vancouver@Flickr) in 2011 in Summerland, British Columbia. Thanks Brian.

Rosa acicularis has a Holarctic distribution, growing in northern Europe, Asia and North America. The subspecies sayi is North American, while subspecies acicularis is Eurasian (and Alaska). The North American subspecies is characteristic of boreal forests with white spruce and black spruce, but also extends into stands of quaking aspen, grasslands, and northern hardwood forests. It can be found as far south as New Mexico.

This perennial shrub can grow up to 1.2 meters in height. Plants bear radially symmetrical flowers on the prickly branches. The stipulate leaves are alternate and pinnately compound, comprised of five to nine leaflets. The flowers have five of both sepals and pink petals. A fleshy rosehip matures in the fall and houses the achenes, or the dry indehiscent fruits.

According to Aboriginal Plant Use in Canada's Northwest Boreal Forest by Robin J. Marles et al., First Nations peoples ate rose hips fresh after removing the seeds, or processed the hips into jellies, beverages, or syrups. Traditional medicinal uses included preventing colds and fever by eating the hips and treating eye soreness by using a decoction made of the root as eye drops.

Armeria welwitschii bears no common name in English other than thrift, but in Portugal it is known as "Erva-divina" or "Raiz-divina" (divine-herb or divine-root). Unfortunately, I wasn't able to find an explanation on why it is divine, other than Rosa's speculation at Blog de cheiros that it is because of its magnificent form and harsh environment: Armeria welwitschii. A Portuguese endemic, Armeria welwitschii is native to seaside dunes and cliffs, occurring no more than 250m from where the sea meets the land (link has additional photographs). I don't know if the species is legally-designated as being threatened, but the invasive Carpobrotus edulis has been observed to take over its habitat (ref: Armeria welwitschii at O Botânico Aprendiz na Terra dos Espantos).

For cultivation information, see Cal's Plant-of-the-Week: Armeria welwitschii.

Today's photo of Dicranella heteromalla, or dicranella moss, was taken by Robert Klips (aka Orthotricum@Flickr) on November 24, 2012 in Delaware County, Ohio, USA. Thanks Robert!

Dicranella heteromalla is a member of the Dicranaceae. This common moss species is found at low to high altitudes across North America, Europe, eastern Asia, and northeast Africa as well as sporadically in South America, Central America and some Atlantic Islands. It tends to grow in shaded, disturbed areas with acidic soil.

This dioicous species grows 10-40mm in height in yellow to dark-green shiny tufts. Like all plants, there is an alternation of generations life cycle. Bryophytes are gametophyte-dominant (the main photosynthetic phase), and the cushiony form bears the nutritionally-dependent sporophyte. To learn more, see UBC Professor of Teaching Shona Ellis's short video on the life cycle of mosses.

Today's photographs of Ficus carica 'Brown Turkey', or the 'Brown Turkey' common fig, were taken in UBC Botanical Garden's Food Garden. The Garden currently has two fig trees (the other is Ficus carica 'Desert King'). Both trees are espaliered, and currently in flower. 'Brown Turkey' and 'Desert King' are the two common fig cultivars traditionally considered able to withstand Vancouver's climate, but some gardening experts suggest perhaps six different cultivars may be able to endure the warming winters of British Columbia's southern coast (see: Changing weather and changing crops on south coast via the Vancouver Sun).

The first memorable time I encountered figs was while traveling in Morocco where I saw many fig trees, and also ate quite a bit of the dried fruit purchased from vendors at market stalls in the medinas. They were often displayed in baskets or hanging on strings right on the edge of the small pathways, and consequently were covered in a layer of dust. Nevertheless, they were still tasty.

This deciduous shrub or small tree species belongs to the Moraceae (the mulberry or fig family) and is thought to be native specifically to southern Arabia (ref: Janick and Paull's The Encyclopedia of Fruit & Nuts), but many references will instead state it is native to western Asia and the Mediterranean. Due to a long history of cultivation, Ficus carica is considered an ancient fruit (PDF). This is likely the reason for the uncertainty about its native distribution. Figs are cultivated globally in tropical, subtropical, and warm temperate climates. Modern-day production is over one million metric tons (2006 data).

Exceptional specimens of Ficus carica have attained heights of 12m (ref: Janick and Paull), but more typical heights in cultivation are 5 to 8m. Plants have large, palmate and hairy 3-5-lobed leaves attached to silvery-barked branches. The shiny receptacle or synconium houses the small green flowers, which are invisible unless this infructescence is opened (as in the first photograph). Wayne Armstrong's always-excellent teaching site explains the life-cycle of Ficus carica (scroll down to the section titled "Summary of the Ficus carica Life Cycle"), but note also that he concludes his discussion with mention that 'Brown Turkey' is parthenocarpic. Unlike the natural species which requires a fig-wasp (Blastophaga psenes) to pollinate, the fruits of 'Brown Turkey' will ripen without pollination.

Fig fruits are considered an excellent source of minerals, vitamins and fibre, as well as being fat- and cholesterol-free. According to R. Veberic et al., a study of some cultivars grown in Slovenia's coastal region also demonstrated that the fruits contained phenolic substances associated with positive effects on human health, such as antioxidant effects and possible prevention of cardiovascular diseases and cancer (see: Veberic, R. et al. 2008. Phenolic acids and flavonoids of fig fruit (Ficus carica L.) in northern Mediterranean region. Food Chemistry. 106:153-157).

I've previously shared the silvery autumn foliage of Elaeagnus commutata, or silver-berry, on BPotD, With today's image, Lotus demonstrates the green spring foliage, the flower and the fine-scaled leaves of this western and northern North America native. Please see the prior entry or the Lady Bird Johnson Wildflower Center's information sheet for additional reading about Elaeagnus commutata.

The plant in today's photograph, however, was growing in the densest occurrence cluster for the species in California's Butte County. If you browse through the Calphotos site for photographs of Fritillaria eastwoodiae, you'll note colour variation in the flowers from greenish-yellow to red. I was fortunate to find an individual with (in my opinion) the more attractive red flowers that could be safely photographed. When photographing rare species, it's critical to minimize damage. In order to do so, one often needs to do "slow walking", where one considers each next step carefully. It's the same sort of walking one does around poison oak, though it becomes even slower when both poison oak and the rare species occur together (as in this instance). Add in another danger--rattlesnakes, for which one stomps in order not to surprise them--and I'm sure that my behaviour is at least mildly interesting to any passersby.

On the topics of passersby and coincidences, while photographing this plant, a US Forest Service botanist happened to walk by on the trail. After a bit of discussion about some of the intriguing plants in the area, we exchanged introductions. He happened to be Lawrence Janeway, who I immediately knew as the person who rediscovered the presumed-extinct Clarkia mosquinii (named after my uncle) (see: Janeway, LP. 1993. Noteworthy Collections. California: Reporting the re-discovery of species thought to be extinct: Clarkia mosquinii ssp. mosquinii and C. mosquinii ssp. xerophila (Onagraceae) Madroño 40:268-269).

Today's photo of Pelargonium tetragonum was taken by Christopher Young (aka c.young@Flickr). Thank you, Christopher.

Pelargonium tetragonum, or the square-stemmed pelargonium, is a shrubby member of the Geraniaceae found in an inland strip of dry habitats paralleling the southern coast of South Africa. Its preference for dry, rocky and well-draining soils helps classify it as a xerophyte.

This species is characterized by its succulent square stems (tetra being the Greek prefix for "four"). Pelargonium tetragonum carries a pair of flowers upon its jointed stems; each flower has four petals with the upper petals larger than the lower. Petals are cream to pink in color with red streaks. These contrasting streaks serve as a nectar guide for its pollinators, who require a long tongue or beak to reach the nectar at the base of the extended floral tube (shown in the photograph). The evergreen leaves of this plant are hairy, fleshy, lobed, and dark green in color, with a dark central blotch (description inspired by Fogg's 1964 work, Geraniums and Pelargoniums).

Among the two hundred or so members of Pelargonium, there is exceptional diversity in colour, size and morphology of the plants, flowers and leaves. Differences in flowers correlate with a difference in pollination syndromes. Species are variously pollinated by bees, long-proboscid hovering flies (illustration), butterflies, hawkmoths, and presumably by a small percentage by birds (see: Struck, M. 1996. Floral divergence and convergence in the genus Pelargonium (Geraniaceae) in Southern Africa: Ecological and evolutionary considerations. Plant Systematics and Evolution. 208:71-97.). From Struck's paper, Pelargonium tetragonum is putatively pollinated by long-proboscid flies, as partly suggested by the length of the floral tube and several observations during the study.

Today's plant photographs are of Sanicula europaea, with the first photograph by Stephen Buchan (aka --- Green Light Images ---@Flickr) and the second photograph by beranekp@Flickr. Both were submitted via the Botany Photo of the Day Flickr Pool. Thank you!

Sanicula europaea, or wood sanicle, is a member of the Apiaceae and can be found throughout most of Europe and southwestern Asia growing in shaded and damp wooded habitats.

This perennial herbaceous species reproduces vegetatively by rhizome cleavages (for extremely local dispersal), but it also has hooked seeds permitting long-distance dispersal through attachment to animal fur (see: Gustafsson, C. & J. Ehrlén. 2003. Effects of intraspecific and interspecific density on the demography of a perennial herb, Sanicula europaea. Oikos. 100: 317-324). Sanicula europaea is an evergreen that reaches 20-60cm in height. The basal leaves are long and petiolate, and bear teeth ending in a short stiff hair or bristle. Inflorescences of this species are considered to be false umbels, taking as long as 16 years to appear in mature plants.

Sanicula europaea has been used as a traditional medicine for treating dermatological, gastrointestinal and respiratory diseases. Air-dried leaves of Sanicula europaea have also been studied by Karagöz et al. for their apparent ability to inhibit Human Parainfluenza Virus (type 2), but the mechanisms of inhibition are yet to be determined (see: Karagöz A. et al. 1999. Antiviral activity of Sanicula europaea L. Extracts on multiplication of Human Parainfluenza Virus Type 2. Phytotherapy Research. 13: 436-438.