Botany Photo of the Day

Krigia virginica

2012-05-24T17:45:12Z

]]> The final natural site we visited during our group trip to the southeast USA a few weeks ago was the Rock and Shoals Outcrop Natural Area near Athens, Georgia. Like many of the sites we visited, we heard "You should have been here three weeks ago" for the best flower displays, as the warm spring had advanced everything by several weeks. Still, we found a number of species of interest, including this Virginia dwarf-dandelion in fruit. It's intriguing structure combined with a bit of morning dew made it a favourite for many photographers that day.

To give a sense of scale, this plant is only about 15cm (6 in.) tall. Many additional photographs showing plants throughout much of the life cycle are available from MissouriPlants: Krigia virginica. For a photograph of a plant resembling a dandelion when losing its seeds, see the blog "Anybody Seen My Focus?": Virginia dwarf-dandelion.

The USDA PLANTS database shows this taxon as occurring throughout much of the eastern USA, as well as occurring in Quebec and British Columbia. The Database of Vascular Plants of Canada notes that the presence of Krigia virginica in Quebec is doubtful, while the British Columbia occurrences are from introduced plants (mapped via E-Flora BC: Krigia virginica).

The Flora of North America entry for Krigia virginica notes the potential for this annual to become an introduction beyond its range, because of "its weedy habit". Other sites, like the Prairie Wildflowers of Illinois, comment that it "is an adorable little plant" and the MissouriPlants site suggests it "would look good in a cultivated rock garden".

FNA also makes note of an interesting morphological tidbit: "Plants collected late in the season have a branching habit remarkably unlike the scapiform vernal form". Today's photograph is of the typical scapiform vernal form, that is, a spring-flowering plant (vernal) with a inflorescence on a single, leafless stalk (scape).

Lotus pinnatus

2012-05-23T20:40:38Z

]]> Today's entry is written by Bryant. The first photograph is from Charles Thirkill, a resident of Nanaimo who has been prominent in preserving this rare species at this location in British Columbia, and the second image is from Bryant. He writes:

Last Thursday, I was fortunate enough to tag along with Daniel Mosquin and Tony Maniezzo, the curator of the North American Gardens (including the Garry Oak Meadow and Woodland Garden, on their scouting trip to various Garry oak ecosystem sites on Vancouver Island. The main purpose of the trip was to examine different Garry oak landscapes and compare the plants and plant assemblages that are growing in the UBC Botanical Garden with their counterparts in the wild. A secondary purpose was to locate and observe rare plant species, in the hope that the Garden will one day participate in conservation programs for these species.

This photo shows Lotus pinnatus (bog birds-foot trefoil), a member of the Fabaceae, at one of its few locations on Vancouver Island. It is a short-lived perennial that grows from a thick taproot, and can be observed in flower from May to June. It has alternate compound leaves, each with 2-4 pairs of oppositely-arranged leaflets and a terminal leaflet. It is found in moist depressions in shallow soil on exposed coastal lowlands. In Canada, it grows in Garry Oak habitat on southeast Vancouver Island and Gabriola Island.

Elsewhere, Lotus pinnatus is native to California, Oregon, Washington and Idaho. The species is not considered threatened globally; however, it is considered extremely rare in Canada (the northern extent of its distribution). In Canada, it is limited to 5 recorded sites, with 83% of its Canadian population residing on the Harewood Plains in Nanaimo, British Columbia. This highly limited Canadian distribution has earned this species an N1 (nationally endangered) ranking by the Committee on the Status of Endangered Wildlife in Canada. Provincially, it is ranked as an S1 (red-listed/critically imperiled) status in B.C., the highest threatened level that can be applied to a species.

Since Lotus pinnatus usually grows in association with water seepage sites, any activity that could cause drainage through soil compaction, channeling or other methods could cause local extirpations of this species. The biggest threats to the British Columbia populations of this species come from logging, unauthorized 4x4, ATV and dirtbike use, development, and encroachment of invasive species. The site where the pictured specimen was found was not marked in any way and showed recent tracks and disturbance from unauthorized recreational vehicles.

Only 7% of the plants in Canada reside under some official protection, those that are in the Woodley Range Ecological Reserve. The percentage of protected habitat for Lotus pinnatus is small because the majority of the Canadian populations exist on private land. Landowners have made efforts to keep off-road recreationists out of the fragile habitat by placing gates, cement barriers and ditches at potential entrance sites, but to little avail. On the bright side, there are steps being taken to help Lotus pinnatus recover. In 2006, the "Recovery Strategy for Multi-Species at Risk in Vernal Pools and Other Ephemeral Wet Areas Associated with Garry Oak Ecosystems in Canada" was developed for Lotus pinnatus, and five other local species, under the Species at Risk Act (SARA). This recovery strategy is a major step in the protection of the mentioned species; the next step requires a proposed action plan, which is currently in the process of development, to delineate site-specific management goals and objectives.

In other news, Lotus pinnatus was named the floral emblem of Nanaimo in 2010 with the hopes to raise public awareness about its conservation status. For information on the local recovery efforts for this species contact the Garry Oak Ecosystems Recovery Team.

Aquilegia chrysantha

2012-05-16T22:44:31Z

]]> Today's photograph and write-up are both by Bryant DeRoy, the BPotD work-study student for this summer. Bryant writes:

Following the wonderful series by Katherine Van Dijk on white-flowered medicinal plants, I thought I would post something with a vibrant colour to mix things up a bit. This photo of Aquilegia chrysantha (golden columbine) was taken in the E.H. Lohbrunner Alpine Garden at the UBC Botanical Garden. Aquilegia chrysantha is a member of the Ranunculaceae (buttercup family) and is native to the southwestern USA and Chihuahua, Mexico. In the USA, the species is found in Utah, Arizona, New Mexico and Texas, as well as a a disjunction in Colorado. These herbaceous perennials are often found in shady moist canyons, usually in association with seeping water. Mature plants in typical growing conditions can range in height from 30cm to 120cm. Compared with other columbines, the inflorescence is relatively large, with the spurs projecting from the back of the corolla typically ranging from 4cm to 7cm in length.

Although Aquilegia chrysantha is known as a shade and moisture-loving plant in its native arid habitat, this species does perform well in gardening conditions outside its native range. The specimen pictured above was planted on a southwest-facing slope in full sun in Vancouver, British Columbia; mind you, "full sun" in springtime Vancouver (at the 49th parallel) is much less intense and more infrequent than full sun in the southwestern USA.

Columbine is derived from columbinus, meaning "dovelike" in Latin. Viewed from certain angles, the flowers resemble a cluster of five doves, with the petals (including the spurs) resembling the heads, necks and bodies of the 5 birds (very elongated in Aquilegia chrysantha!) and the spreading sepals imagined as wings. The genus name is derived from the Latin aquila for eagle, a reference to how the petals can resemble eagle talons. The foliage of this species is also of note for its fern-like and sometimes evergreen qualities. Once it has established, Aquilegia chrysantha will often self-sow, a potential benefit to gardeners who enjoy naturalizing plants.

Hylocereus costaricensis

2012-05-15T21:30:05Z

]]> With today's entry, we conclude Katherine Van Dijk's contributions as a work-study student for Botany Photo of the Day (though the official end date was actually two weeks ago). Thank you Katherine! For this entry, she writes:

To finish our series on white-flowered plants with medicinal properties, we have another wonderful contribution from 3Point141@Flickr. This photograph features Hylocereus costaricensis, commonly known as Costa Rica pitahaya, Costa Rica pitaya or Costa Rica night-blooming cactus. 3Point141@Flickr also has a 12 image set which captures the blooming of this magnificent species: Hylocereus costaricensis.

Pacific Island Ecosystems at Risk (PIER) describes Hylocereus costaricensis as a vigorous vine (up to 10cm in stem width), with white and yellow flowers sometimes exceeding 30cm in length. The site notes Hylocereus costaricensis as native to Costa Rica (costaricensis = "of Costa Rica"), Nicaragua and Panama, but unfortunately invasive in Hawaii.

Hylocereus and a few closely-related genera of cacti are well-known for their tasty dragon fruit or pitaya. The fruit of Hylocereus costaricensis is where medicinal uses are found. In Le Bellec, F. et al., 2006. Pitahaya (Hylocereus spp.): a new fruit crop, a market with a future (PDF). Fruits. 61:237-250, the authors note that dragonfruit is a significant source of antioxidants, including betalains. These compounds are currently being studied for medical efficacy, with some indications that they can be useful in preventing certain diseases (e.g., some forms of cancer). A different medicinal use for Hylocereus costaricensis was examined in a study which had results suggesting that an ethanol extract of the fruit pulp was successful in increasing sperm viability and production rate in mice (and could therefore presumably be used as a male fertility agent). See: Aziz, F. and M. Noor. 2010. Ethanol extract of dragon fruit and its effects on sperm quality and histology of the testes in mice. Biomedical Research. 21(2):126-130.

Vanilla roscheri and Vanilla planifolia

2012-05-15T05:20:05Z

]]> Continuing the series of white-flowered medicinal plants, Katherine writes:

Today's image is of Vanilla roscheri, and was taken by Ton Rulkens (tonrulkens@Flickr) "in the wild on the north Mozambique coast (Mecufi District)". The illustration of Vanilla planifolia is from Köhler's Medizinal-Pflanzen.

Vanilla roscheri is a rare orchid found in eastern and southeastern Africa. Due to deficient data, the conservation status of the species globally is unknown, but in South Africa it is considered endangered due to urban expansion, habitat degradation, invasive species and agriculture. Commonly known as Roscher's vanilla, Vanilla roscheri is found in open bushlands, scrub, mangroves and open evergreen scrub to an elevation of about 1050m (3450 ft.). Sweetly fragrant, the flowers of the plants bloom in the (tropical and subtropical) winter. Plants are succulent vining climbers.

Medicinal information for "vanilla" almost always refers to the extract of vanillin from the commercial Vanilla planifolia, originally of Mesoamerica and northern South America. Vanilla roscheri also seems to contain the compound, as use of the species has been documented in traditional medicines of African indigenous peoples. An excellent article on the origin and use of vanilla is available from UCLA's Louise M. Darling Biomedical Library's Medicinal Spices Exhibit, where the following from Robert Bentley and Henry Trimen's Medicinal Plants; being descriptions with original figures of the principal plants employed in medicine and an account of the characters, properties, and uses of their parts and products of medicinal value (London, Churchill, 1880) is quoted: "Vanilla is an aromatic stimulant, with a tendency towards the nervous system. It has also been regarded as an aphrodisiac. It has been employed as a remedy in hysteria, low fevers, impotency, etc. But its use as a medicine is obsolete in this country, although still sometimes employed on the Continent and elsewhere."

Sambucus racemosa subsp. pubens var. arborescens

2012-05-12T01:30:04Z

]]> Bryant DeRoy, who is the summer work-study student, is both the photographer and writer for today's entry. It fits with the white-flowered medicinal plant series, so we'll interrupt Katherine's entries today with one of his since it features a species from UBC Botanical Garden.

This photograph of the blossoms of Sambucus racemosa subsp. pubens var. arborescens (Pacific red elderberry) was taken from the Greenheart Canopy Walkway in UBC Botanical Garden's David C. Lam Asian Garden. Sambucus racemosa subsp. pubens var. arborescens is a member of the Adoxaceae (or muskroot family), which is a relatively small family consisting of only 150-200 species.

There is some controversy and confusion around the use of Pacific red elderberry as a source of food and medicine. The controversy arises because the leaves, bark, stems, seeds and shoots contain glycosides, which produce cyanide. The confusion often occurs because a close relative, the European Sambucus nigra, is more commonly used for food and medicinal purposes. However, despite its toxicity, the Pacific red elderberry has been an important resource for many First Nations along the west coast of North America (including the Chehalis, Hanaksiala, Hoh, Klallam, Makah, Nitinaht, Oweekeno, Quileute, Skagit, Snohomish, and Squaxin).

Eating the fruits raw is typically avoided. Instead, traditional First Nations preparation of the fruits involves steaming on rocks or baking in pits. The cooked berries can then be processed to remove stems and seeds, followed by being wrapped in the leaves of Lysichiton americanus (western skunk cabbage) for future use. The glycosides are heat labile, making them less toxic when cooked. Since the fruits have low levels of pectin, this mash is traditionally combined with other fruits such as blueberries or crabapples (which contain higher levels of pectin) in order to make a jam-like preserve. Also, combining the Pacific red elderberry fruits with other fruits or fish grease (sourced from eulachon) can make them more palatable, due to the tart nature of the berries. The fruits of Sambucus racemosa subsp. pubens var. arborescens contain high levels of vitamin C, which made them especially important as a winter food for First Nations (when other sources of vitamin C were scarce, centuries ago). Even though cooking the berries can make them less toxic, eating high quantities of cooked berries can still induce nausea, vomiting and diarrhea.

Traditional First Nations medicinal preparations of Sambucus racemosa subsp. pubens var. arborescens included the decoction into teas, poultices and infusions of the leaves, bark and roots. These were (are?) used to treat boils, colds, coughs, pain, arthritis, gastrointestinal issues, and even nervous breakdowns. Boiled leaves were/are also used to shorten pregnancy as well as aiding in childbirth. See Daniel Moerman's 1998 book Native American Ethnobotany for a more detailed description of use by First Nations.

Additional food uses include infusion of the flower clusters to flavour wines or make tea. There are also reports of the flowers being added to pancake batter as well as being dipped in batter and fried like tempura. I have sampled the latter, and found that cooking did not completely remove the foul odour that is commonly associated with members of the Adoxaceae. Perhaps it is an acquired aroma?

Peumus boldus

2012-05-10T17:49:18Z

]]> Another in the series on white-flowered medicinal plants written by Katherine, today's entry has an illustration from Köhler's Medizinal-Pflanzen (in the public domain, via Wikimedia Commons). Katherine writes:

Peumus boldus was described and published by Molina in 1782. Synonyms include Ruizia fragrans and Boldoa fragrans. Among its many common names are boldo, boldu, boldina, and baldina. This Chilean endemic species is the only representative of the genus.

Mature plants of this dioecious (individual plants are either male or female) evergreen tree attain about 6-8m (15-25 ft) in height. Shown in the illustration with pink-tinged white flowers, photographs of living material range from white to a pale yellow colour. The Plants for a Future database entry on Peumus boldus notes: "The small fruits are dried and used as beads in necklaces. When warmed by the body or the sun they release the scent of cinnamon". The leaves are the primary part of the plant used, however.

Wikipedia touches on some of the uses of the leaves: "In Chile, Uruguay, and Paraguay boldo is frequently mixed with yerba mate or other teas to moderate its flavor. In Brazil and Paraguay, many families keep a boldo plant at home for this purpose, although boldo teabags are readily available in nearly all supermarkets. It is believed in Southeastern Brazil that the leaves of the boldo plant can be used as an effective hangover and upset stomach cure." A longer list of traditional medicinal uses is available from Plants for a Future (linked above), including: treatment of gallstones, liver pain, gonorrhoea, urinary tract infections, intestinal parasites and rheumatism.

The European Medicines Agency, in its Evaluation of Medicines for Human Use, noted in its final assessment report on Peumus boldus (PDF): "[Assessor's Overall Conclusions] Sufficient data are available to develop a Community herbal monograph on the traditional use of Peumus boldus Molina, folium provided the indications are suitable for self-medication. The proposed indications are in accordance with the Commission E monograph (Blumenthal, 2000): Traditional herbal medicinal product for symptomatic relief of dyspepsia and mild spasmodic disorders of the gastrointestinal tract."

but cautioned:

"Duration of use should be limited to 2 weeks. Use of boldo leaf is not recommended in children and adolescents and should be avoided during pregnancy and lactation. Boldo leaf is contra-indicated where there is obstruction of the bile duct, cholangitis liver disease, gallstones or any other biliary disorder that would require medical supervision. The use of comminuted herbal substance as such and of ethanolic extracts of boldo leaf are not considered acceptable for traditional herbal medicinal products in view of the potential risks associated with the toxic ascaridole (see Health Issues) constituent".

Pseudobombax ellipticum

2012-05-09T22:41:32Z

]]> Katherine continues with the series she's assembled:

Today's image for the series on medicinal white-flowered plants is Pseudobombax ellipticum (shaving-brush tree), thanks to 3Point141@Flickr. The image was taken at Palma Sola Botanical Park, Bradenton, Florida, USA.

According to the USDA GRIN site, Pseudobombax ellipticum is native to Mexico, Cuba and Guatemala. GRIN lists two synonyms, Bombax ellipticum and Carolinea fastuosa, as well as some common names: shaving-brush tree in English, pochote or pochotl in Spanish, and rakborstträd in Swedish. Jim Conrad's Naturalist Newsletter also provides additional names for Pseudobombax ellipticum: amapolo (Mayan), xiloxóchitl (cornsilk flower, Aztecan and current in some parts of Mexico), and cabellos de ángel, or angel hair (Spanish).

A species description written by Navarrette-Tindall and Núñez for the Tropical Tree Seed Manual is available via rngr.net (Reforestation, Nurseries and Genetic Resources: Pseudobombax ellipticum. Among the other details about this white- or pink-flowering species, the account notes the species is winter- to spring-flowering, typically after losing its leaves. The authors also provide several uses of Pseudobombax ellipticum: the wood is used as firewood or for carving dishes; the trees for ornamental purposes and as living fences; the toasted seeds as food; and the fine fruit fibres to fill pillows and mattresses or to insulate refrigerators. Medicinally, the authors cite González (1994) and Guzmán (1980): "In El Salvador, the tea of the flowers is used for gastrointestinal ailments and the tea of the fresh bark is used to treat diabetes". The link above to Jim Conrad's newsletter also describes some medicinal uses by local peoples.

Researchers have determined that Pseudobombax ellipticum was one of several important plant species depicted in Mayan ceramics (e.g., pots used as burial urns or incense holders). See Sacred plants of the Maya forest for a popular account from the BBC, or investigate Zidar, C. and W. Elisens. 2009. Sacred Giants: Depiction of Bombacoideae on Maya Ceramics in Mexico, Guatemala, and Belize. Economic Botany. 63(2):119-129. doi: 10.1007/s12231-009-9079-2.

Plumeria obtusa 'Singapore'

2012-05-08T22:25:37Z

]]> Today, we'll start Katherine's series of entries on white-flowered medicinal plants. She writes:

This image of Plumeria obtusa 'Singapore' is courtesy of Dinesh Valke (dinesh_valke@Flickr). For this series on medicinal plants, one should assume that traditional and sometimes scientifically unproven uses are noted, unless otherwise stated. I made my best attempts to find scientific articles where possible.

In Mabberley's Plant-Book, 8 species are noted for Plumeria, with two receiving mention as often-cultivated ornamentals in this tropical American genus: Plumeria obtusa (native to the West Indies) and Plumeria rubra (native from Mexico to Panama). Both of these species are widely cultivated throughout the tropics. Despite having only a couple handfuls of species, hundreds of cultivated varieties have been selected or hybridized, including today's evergreen cultivar. If researching Plumeria rubra, do note that many sites and references use the synonym Plumeria acuminata.

The U.S. National Tropical Botanical Garden (NTBG) provides wonderful descriptions of both Plumeria obtusa and Plumeria rubra, along with their uses. The site notes that Plumeria flowers are used to make lei in Hawai'i, due in part to providing large numbers of showy flowers that retain colour and fragrance. The same source also notes that the scent varies widely among cultivars; this reference by Richard Criley of the Department of Tropical Plant and Soil Sciences at the University of Hawaiʻi at Mānoa details 40 or so cultivars, with comments on fragrance: Plumeria in Hawaiʻi (PDF). The National Tropical Botanical Garden also makes note of the use of Plumeria as an ornamental for cemeteries (hence one of the common names, graveyard flower) and temples (known as temple flower in India and Sri Lanka). Today's cultivar is commonly known as 'Singapore' graveyard flower.

Medicinally, Plumeria species have traditionally been used to treat itches, swellings and fevers, skin eruptions and abscesses, dysentery, herpes, syphilis, coughs and as a purgative. A recent test of the leaves of Plumeria obtusa for anticancer properties did not find significant positive results (unlike some other members of the Apocynaceae): Wong et al. 2011. Antiproliferative and phytochemical analyses of leaf extracts of ten Apocynaceae species. Pharmacognosy Research. 3(2):100-106. However, a 2006 study by Gupta et al. suggested that an extract from the leaves of Plumeria acuminata can soothe inflammation in "both acute and chronic models": Antiinflammatory evaluation of leaves of Plumeria acuminata. BMC Complememnt Altern Med. 6(36).

Coccomyces dentatus

2012-05-03T23:11:27Z

]]> We'll be starting a series from Katherine either tomorrow or Monday on "white-flowered medicinal plants". That series will, for the most part, conclude her contributions as a work-study student. Today's article, though, is written by Bryant Deroy, who is joining us as a work-study student over the summer (funded by your many kind contributions). Bryant writes:

A big thank you to Richard Droker for this striking image of Coccomyces dentatus, which has colonized the dead leaf of a Berberis nervosa (syn. Mahonia nervosa).

Information on Coccomyces dentatus is extremely hard to come by and some sleuthing was required to dig up the details on this species of fungus. Coccomyces are a genus of foliicolous fungi, meaning that they colonize the leaves of vascular plants. Coccomyces dentatus can be found on the dead and decaying foliage of a number of other species including Gaultheria shallon, Arbutus menzeisii, other Berberis spp., Castanea spp., Quercus spp., and Rhododendron spp. among many others.

The black spots are hexagonally-shaped ascocarps made up of six triangular "flaps" that open upon maturity to allow the fertile spores within to be released. Richard has some close-up photos of this process. The borders that form the mosaic patterns occur where two mycelia contact each other and are sexually incompatible. The distribution of this species is widespread, although it appears to be most prominent in temperate zones. The staining and mosaic patterns vary greatly, this example being the most visually stunning that I have come across.

Quercus virginiana

2012-04-30T20:41:53Z

]]> The Squares of Savannah, Georgia often have a canopy of Quercus virginiana, or southern live oak. This photograph, from Chippewa Square, was one of many taken of the oaks that day. Incidentally, Chippewa Square is also the locality of the park bench scenes from Forrest Gump (I was oblivious and only learned about it later).

Like the previous Cladonia evansii, Quercus virginiana has a distribution that stretches along the coastal plain of the southeast USA. Like many oak species, it is known to hybridize; some named hybrids are listed in the Flora of North America account for the species: Quercus virginiana. The FNA account also details some of the past economic importance of the species: "...it was widely used for structural pieces in the manufacture of wooden ships, and large groves were actually considered a strategic resource by the federal government. Historically oil pressed from the acorns was utilized. Like other members of the live oak group...Quercus virginiana seedlings form swollen hypocotyls that may develop into large, starchy, underground tubers. In the past, the tubers were gathered, sliced, and fried like potatoes for human consumption".

The epithet virginiana refers specifically to Virginia, USA. The state name, in turn, "may have been suggested...by Raleigh or [Queen] Elizabeth, perhaps noting her status as the 'Virgin Queen', and may also be related to a native phrase, 'Wingandacoa', or name, 'Wingina'"). The etymology of virginiana was the subject of some discussion during our trip, so I hope that this clarifies the matter.

Cladonia evansii

2012-04-26T18:44:13Z

]]> One of the many highlights of our recent trip was a visit to the Ohoopee Dunes Natural Area near Swainsboro, Georgia, where Dr. Mincy Moffett gave us a tour of this uncommon ecosystem. The Ohoopee Dunes are the most extensive riverine sandhill formation in Georgia, and host a number of rare and threated animal and plant species.

One vignette of the tour was this location where Cladonia evansii, also known as powder-puff lichen or deer moss, was found in abundance. With its dense clusters of greyish-white round tufts, it looked like someone had assembled a collection of miniature tumbleweeds in the oak leaf litter (I think it's bluejack oak, Quercus incana). While we all admired the amount of this lichen in this location, Alan Cressler has a photograph of an even denser stand from a different tract of the Ohoopee Dunes: Cladonia evansii.

In the USA, Cladonia evansii is found along the coastal plain of the eastern seaboard, ranging from Texas to at least North Carolina (and perhaps even further north -- I can't tell on the map I've used). It is also found in the Caribbean. Its habitat preference is partially shaded or open ground, typically in sandy areas. Additional images are available from ForestryImages.org: Cladonia evansii and Sharnoffphotos.com: Cladonia evansii.

Hoheria sexstylosa

2012-04-25T20:45:05Z

]]> An entry from Botany Photo of the Day work-study student Katherine today:

Today's picture, from Tony Foster (Tonyfoster@Flickr), is of the beautiful flower of Hoheria sexstylosa. Additional photographs of this species are available via Flickr: Hoheria sexstylosa. Malvaceae.Info states Hoheria sexstylosa is one of the few (from 3 to 6) recognized species of Hoheria, all of which are endemic to New Zealand. That reference also states Hoheria sexstylosa is an evergreen woody plant which grows to be 8 metres in height with a spread of 6 metres. Plants are usually multi-stemmed. The summer- to autumn-blooming flowers are 5-petalled, scented, star-shaped, white and up to 2.5cm across. Fruits are reportedly similar to Hoheria populnea with white or purple "coloured wings", while the wood is a "tough white timber" which may be used for cabinet-making or firewood.

The Plants For A Future (PFAF) database says that although the inner bark is edible, it is primarily a famine food, although Hoheria sexstylosa may be dried, ground into powder and used to thicken soups or mixed with cereals when making bread". PFAF also notes the closely related Hoheria populnea is known to be used for making ropes and cord, and suggests that Hoheria sexstylosa may have a similar use.

The genus name stems from the Maori name, houhere while the epithet means "with six styles". According to Malvaceae.info, Hoheria sexstylosa is commonly known as long-leaved lacebark (lacebark refering to two other species) and ribbonwood. Although some sites refer to Hoheria sexstylosa by the common name stardust, I believe this should only be used in reference to a specific cultivar ('Stardust', which earned an "Award of Garden Merit from the Royal Horticultural Society).

Cissus verticillata

2012-04-24T20:19:16Z

]]> The display of the aerial roots of Cissus verticillata (syn. Cissus sicyoides) makes for an iconic photograph in Atlanta Botanical Garden's Fuqua Conservatory. Easily ranked as one of the most impressive conservatories I've visited, it helped our recent trip start on a very positive note.

Known by a number of common names, including princess vine, millionaire vine and (with an appropriate adjective) curtain ivy, Cissus verticillata is native to much of the tropical Americas. I've not been able to track down any proven reasons why the species would evolve such extensive aerial roots, though some speculation can be made. One suggestion is access to additional water resources; please see the article "A Curtain of Roots" on page 27 of Gardenwise (Vol. 36, PDF), the magazine of the Singapore Botanical Garden. Whatever the reason(s), the aerial roots are also intriguing in terms of their high growth rate, measured under seemingly ideal conditions at about 8mm/hr (about an inch every 3 hours or so).

Additional photos of this grape relative, including images of leaves and fruit, are available from the Plants of Hawaii site (where the plant is non-native): Cissus verticillata.

Prosartes maculata

2012-04-21T03:40:36Z

]]> Today's image was taken earlier today by Tony Maniezzo, the North American Gardens Curator at UBC Botanical Garden. This spotted mandarin was photographed in the Nantahala National Forest of North Carolina, USA, during one of the last few walks of the trip we are leading. While we sometimes encountered its relative Prosartes lanuginosa (yellow mandarin) on other walks, this was the only time we observed this species. Most references to this species will suggest it is named Disporum maculatum, now considered a synonym.