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.

A day-trip to collect specimens for a couple research projects earlier this week yielded an opportunity to photograph these small western alpine laurels. Growing at an elevation of 1920m (6300 ft), these diminutive plants (10cm / 4in) are referable to the broadly distributed Kalmia microphylla var. microphylla of western and northern North America. A second variety is recognized by the Flora of North America, Kalmia microphylla var. occidentalis, which tends to be both taller (sometimes to 80cm) and distributed only from Alaska to Oregon at lower elevations. Anatomically, leaf blade shape and dimensions are also used to distinguish the two varieties, with variety microphylla having shorter, stouter leaves.

According to Flora of North America, flower colour is "rose-purple, rarely white", so I was fortunate to find one of the white-flowered plants. Only one small section, perhaps 0.5m², of the entire local population of these plants was white, so it is possible that the white-flowered individuals were growing clonally.

The US Forest Service's Celebrating Wildflowers site has an excellent account of Kalmia microphylla, and more photographs are available via CalPhotos: Kalmia microphylla.

Today's entry was written by Alexis:

From the Botany Photo of the Day Flickr Pool, Doug (shyzaboy@Flickr) shares this photograph of Morinda citrifolia taken in Puerto Plata, Dominican Republic. Thanks, Doug!

Morinda citrifolia is now fairly widely distributed around the world and goes by many names in different countries; it is often called noni, a Hawaiian term, and its English names include rotten cheesefruit, Indian mulberry, and canary wood. Though the species originated in southeast Asia and Australia, it is now naturalized in tropical regions of the Pacific, North America, and South America. Evidently, Morinda citrifolia (PDF) has been known to successfully establish after spreading to new areas, giving it the potential to become invasive. A unique trait the seeds have is the ability to stay viable for several months while in water--a useful skill when dispersing across oceans or rivers. However, the species is not currently considered a major threat.

Morinda citrifolia grows as a shrub or small tree, blooming in the summer and autumn. From a cluster of its flowers comes a single compound fruit or syncarp; the still-developing fruit in the photograph can be expected to turn yellow-white and grow to 5 to 10 cm in length. If you're looking for a possible natural remedy for ailments such as headaches, high blood pressure and muscle pains or if you just need some Vitamin C, the juice of the fruit can be drunk and is sold commercially. The species has also been investigated for prevention of cancer.

I was fortunate last week to join Ed Alverson of The Nature Conservancy and Tanya Harvey (and her husband Jim), author of the in-development Mountain Plants of the Western Cascades of Oregon and Where to Find Them on a hike in the Table Rock Wilderness (southeast of Portland, Oregon). I was keen to see the species featured today, Enemion hallii. Tanya had seen it in the area previously, which she detailed on her weblog, Plants and Places: Rock-hopping at Table Rock Wilderness. Given that most plants have had late flowering dates this year in our bioregion and given that the plants of Enemion hallii were well in-bloom on July 22 of last year, we thought we'd be certain of finding Enemion hallii in bloom on July 29. Not so. Hours of searching for plants in bloom at the same elevation Tanya encountered them last year were all for naught, though budding plants were found. Descending the mountain, several more local populations were newly encountered, but none of these were any further along. Finally, after cameras were put away and some of us were preparing to leave, the ever-tenacious Ed found 3 plants in bloom, within 75m of where the vehicles were parked. Tanya goes into more detail on the search in her weblog posting: The Quest for Enemion Flowers at Table Rock.

Unlike the diminutive Enemion stipitatum featured earlier this year, Enemion hallii (or Willamette rue-anemone) is a robust perennial, sometimes attaining 85cm or so in height. As the Flora of North America notes, it is a species of "moist woods and streambanks", which is generally where we observed the populations, though the higher-elevation plants were growing in a north-facing talus slope, where the combination of shade and cool temperatures (and perhaps seeping water under the boulders?) provided sufficient conditions. I had never previously seen Oplopanax horridus growing amongst boulders, so I suspect cool, wet soil was available.

Enemion hallii is endemic to southwest Washington and northwest Oregon, with the exception of one disjunct population in the Siskiyous of southwest Oregon.

Today's entry was written by Alexis:

Anne Elliott (annkelliott@Flickr) shares this photo via the Botany Photo of the Day Flickr Pool and writes, "The nodding/musk thistle is my favourite kind of thistle, especially at this stage, when the pinky purple flower has died and the beautiful pattern of the spiny bracts can be seen more clearly. Flower head is 4-6 cm in diameter. Photographed at the Erlton/Roxboro Natural Area on July 27th, when I called in for a short walk after my afternoon volunteer shift. There were a lot more of these plants this year, so I guess this invasive weed really does spread". Thank you, Anne!

The name nodding thistle refers to the plant's large flower head, which is often seen bobbing up and down. Wikimedia Commons has a picture of the flower in full bloom.

Carduus nutans occurs naturally in western Asia and across Europe. In North America, however, the species is a major weed, especially in farmlands. It out-competes native plant species, creating dense colonies that livestock refuse to walk through and cannot eat because of the spines. As an invasive species, the musk thistle has an advantage since it lacks natural predators and can spread its seed quite quickly.

In the United States, biological methods of pest control have been implemented in addition to chemical and mechanical approaches. Two species of weevils from Europe, Rhinocyllus conicus and Trichosirocalus horridus, have been introduced to some areas affected by Carduus thistle invasions; the former target the plant's developing seeds, while the latter eat the root crowns. Yet, as with many pest control methods, this one is not without risk, as the introduced insects may also affect non-target species. In Wisconsin, for example, the weevils are not used due to the associated threat to rare thistles native to the state.

A trip last week to Washington's Olympic National Park afforded me the opportunity to revisit some favourite species, including today's elephanthead lousewort. These plants were growing on one of the infrequently-accessible wet turf slopes that can be found along the upper reaches of Hurricane Ridge Road.

Named after Greenland, the species can be found through much of northern Canada and Greenland at low to moderate elevations, as well as throughout much of western USA and Canada, where it can be found at moderate to high elevations. It is a species associated with wet areas. I think my first encounter with it was while navigating a wet meadow in Banff National Park, where I was quite distracted trying to discern what plant had these strange purplish-green leaves.

Additional photographs of Pedicularis groenlandica are provided by the Burke Museum.

Alexis wrote today's entry:

The series of plants endemic to the Hawaiian Islands concludes today with Erythrina sandwicensis. These photographs (photo 1 | photo 2) were taken by Forest and Kim Starr, and accessed through Wikimedia Commons.

This tree occurs on leeward slopes on all eight major Hawaiian Islands, as they prefer hot, dry, rocky environments. The species also grows on old lava fields, dry canyons and gorges. Wiliwili loses its leaves in late summer or autumn, and flowers bloom in early spring or summer, so leaves and flowers are rarely seen together. Though the flowers are commonly orange, colour polymorphism exists within the species and white, yellow, peach, red or light green flowers also occur. Additionally, the presence of lichens tends to give the wiliwili trunks an orange tinge (Pratt's A Pocket Guide to Hawaii's Trees and Shrubs (2006)).

Erythrina sandwicensis is known for possessing among the lightest wood of all Hawaiian trees. For this reason, native Hawaiians found it was a useful material for surfboards and outriggers for fishing canoes (Rock's The Indigenous Trees of the Hawaiian Islands (1974)). This species is the only member of Erythrina native to Hawaii. Its Hawaiian name wiliwili, meaning "repeatedly twisted", refers to the seedpods that twist to reveal their red seeds. These are commonly strung together to make leis.

Alexis is the author of today's entry:

Today we feature another plant endemic to Hawaii. Thank you to Karl Magnacca who shares his photograph of Hawaii's state flower, ma`o-hau-hele or yellow hibiscus, from his website.

Hibiscus brackenridgei is one of six native Hawaiian hibiscus species, most of which are endemic to the Islands. It grows as a tall shrub or small tree, naturally occurring in dry forests and shrub lands. Now extremely rare in the wild, this species exists mainly under cultivation in parks and gardens. In 1923, hibiscus was declared the state flower and many considered this to be the native red hibiscus. It was not until 1988 that Hawaii's State Legislature specified the yellow Hibiscus brackenridgei as the state flower.

Though its physical form varies from island to island, there are generally two subspecies: Hibiscus brackenridgei subsp. brackenridgei on Molokai, Lanai, Maui, and Hawaii, and Hibiscus brackenridgei subsp. mokuleianus, on Kauai and Oahu. The latter is distinguished (in part) by having tiny spines on the branches as well as leaves with more serrated margins and pink veins; there are also tiny spines on the branches. Both subspecies are listed as Endangered.

Alexis wrote today's entry:

Continuing the series on endemic Hawaiian species, thank you to Forest and Kim Starr for their photo of Acacia koa uploaded to Wikimedia Commons. Found on all the main islands excluding Ni'ihau and Kaho'olawe, Acacia koa is the second most common forest tree in Hawaii (the most common being Metrosideros polymorpha).

Acacia koa can adapt to wide range of conditions, from elevations of about 60 to 2000m and forests that vary from dry to wet (Wagner et al's Manual of the Flowering Plants of Hawaii (1990)). The growing habit of the species tends to differ depending on the natural environment; in open areas, the trunk is short (4-6m) and the crown is wide and large, while in rainforests, the bark is smoother and the trunk is straight and reaches a height of about 12m before branching occurs (Rock's The Indigenous Trees of the Hawaiian Islands (1974)).

The sickle-shaped "leaves" of this species are actually phyllodes, modified petioles that function as leaves and perform photosynthesis. The true leaves are bipinnately compound and are only present on saplings; adult trees usually only possess phyllodes, and not the true leaves. For a comparison of a phyllode and the true leaf, see this photograph via The Maui Plant Chronicles.

Acacia koa wood is expensive and much in demand. It is arguably the most commercially valuable tree of the Islands. The Hawaiian name koa has several translations including "warrior", "brave", or "fearless" and historically, native Hawaiians carved the trees into war canoes. Today, it is known for its use in construction work, furniture and cabinet making, and the crafting of musical instruments.

Another entry written by Alexis today for the Hawaiian endemic plant series:

Today's photo was taken by Karl Magnacca, who has several interesting photo collections on his website. Thank you very much, Karl! This species is also known as Hawaiian tree cotton or koki'o.

Kokia drynarioides is a tree in the hibiscus family, Malvaceae. Its flowers appear similar to those of a typical hibiscus, but have petals that are curled and twisted. Additionally, the staminal column is curved, likely to suit the curved bills of honeycreepers that feed on the nectar and pollinate the flowers. Kokia is endemic to Hawaii and includes three other species, Kokia kauaiensis, Kokia cookei, and the extinct Kokia lanceolata, found respectively on Kauai, Molokai, and Oahu. Kokia drynarioides is only found on the Big Island.

Listed as Critically Endangered, fewer than ten plants in three populations of Kokia drynarioides are known to exist in the wild (as of 1998), though more can be found in cultivation. Invasive species, overgrazing, human development and forest fires have all played a role in reducing the numbers of this species, and consequently the numbers of honeycreepers that rely on Kokia drynarioides and other nectar-rich species for food have also been reduced.

Alexis is the author of today's entry:

Thank you to Forest and Kim Starr for their photographs of Capparis sandwichiana (photo 1 | photo 2), in order to continue the series on endemic plants of Hawaii.

Capparis sandwichiana is Hawaii's only native caper. Capparis is the Greek word for "caper", while sandwichiana is a reference to the Sandwich Islands--a name James Cook gave the Hawaiian Islands in the 1770s after the fourth Earl of Sandwich, John Montagu (supporter of Cook's voyages). The flowers are night-blooming, emerging white in the evening and slowly turning to pink as they wilt with the rising sun. Despite its Hawaiian name maiapilo, which means "bad smelling banana", the white flowers of Capparis sandwichiana are said to possess a pleasant lemony fragrance (though, the pulp of the fruit is smelly). Moths, e.g., Manduca blackburni, feed on the nectar and pollinate the flowers. The fruits are in turn eaten by birds.

This species can be found on all eight major Hawaiian Islands and also some of the northwestern Hawaiian Islands, specifically the Midway, Pearl and Hermes atolls and the island of Laysan. Capparis sandwichiana grows on volcanic rock, old corals, rocky cliffs and ravines in dry conditions near the coast, but it is still a relatively rare species and is listed as Vulnerable on the IUCN Red List.

Traditionally, native Hawaiians crushed the maiapilo plant and used it to heal broken bones, while its sap was a treatment for boils.

Alexis wrote today's entry:

This species is the first in a series that will feature plants endemic to the Hawaiian Islands. Thank you to Chlorophil7@Flickr who took this photograph and Brian (aeranthes@Flickr) who shared it with our Flickr pool. This particular plant of Brighamia insignis, also known by its Hawaiian name olulu, was growing at the Como Conservatory in Saint Paul, Minnesota, USA.

Brighamia insignis is a tree-like shrub that usually grows 1 to 2m tall but sometimes can reach 5m in height. Its shiny leathery leaves create a rosette formation at the top of the stem, giving it a unique appearance described by its common name, cabbage-on-a-stick. This shrub has a succulent stem that fattens towards the bottom of the plant; usually, it is unbranched.

Currently, Brighamia insignis is only found on the island of Kauai, though in the past it was also present on Niihau. It has not been observed on Niihau since 1947, however. The island of Molokai is host to a related species, Brighamia rockii, whose flowers are white instead of yellow and whose seeds are smooth, not bumpy. Both species are adapted to grow on windy sea cliffs, as their thickened stems support them in strong winds and their roots can grow in rocky crevices.

Listed as Critically Endangered by the IUCN, only seven individuals were reported to be alive in the wild as of 2003. In 1992, Hurricane Iniki wiped out 60 to 70 Brighamia insignis individuals, half of the known individuals at the time. Brighamia insignis continues to be threatened by herbivory and habitat degradation by goats, human disturbances, invasive plants, fires, landslides, and the loss of pollinators (a sphingid moth). Though they are extremely rare in the wild, many tropical botanical gardens and conservatories around the world have this species in their collections. They are favoured for their yellow flowers that give off a sweet honeysuckle-like fragrance.

Alexis wrote today's entry:

Sergio Niebla (sergioniebla@Flickr) took this photograph of two plants of Nolina nelsonii plants (with Agave americana on the right) in La Reforma, Tamaulipas, Mexico. Thank you, Sergio! This species is native only to the state of Tamaulipas, though it is also cultivated, especially in Texas.

Blue nolina or Nelson's bear grass goes by the scientific name Nolina nelsonii. Its physical appearance is often compared to species of Yucca, another genus in Asparagaceae. Nolina nelsonii leaves are narrow and long, up to about 80 cm in length, with miniscule teeth lining their margins. Plants resemble a small trees, with a head of the rigid, blue-green leaves sitting atop a 1-3.7m tall trunk. The inflorescence that protrudes from the foliage can measure 2-3.4m in length, adding to the plant's already unusual appearance.

Nolina nelsonii prefers well-drained soils and sunny environments. Not only is it drought tolerant, but it can also survive freezing temperatures down to -12°C. (Irish & Irish's Agaves, Yuccas, and Related Plants (2000))