Toxicoscordion venenosum

Toxicoscordion venenosum is a bulb plant tall when flowering in the spring or early summer. The underground bulbs are egg-shaped () and , made of up of multiple layers protected by dried outer layers like an onion. The plant's leaves appear very early in the spring and are narrow. Most of the leaves are basal, springing directly from the ground, though a few much smaller ones may attach to the flowering stem. The length of the leaf blade is long while only being wide. The petals and sepals are very similar to each other and so are often called tepals. A diploid, its chromosome count is 2n=22. Similar species The closely related foothills death camas (Toxicoscordion paniculatum) has a very similar appearance, but with smaller flowers, more open clusters, and multiple flowers on each stemlet (a panicle). ==Taxonomy==

Toxicoscordion venenosum was given its first scientific name, Zigadenus venenosus, and described by Sereno Watson in 1879. The botanist Per Axel Rydberg proposed the new genus Toxicoscordion in 1903 and placed the species there. this is the accepted name according to Plants of the World Online and World Flora Online. However, many sources such as the Flora of North America still list it as Zigadenus venenosus. However, it was generally recognized as a separate species until the 21st century. This variety is differentiated by more often having branches on it flowering stems and the outer tepals being less curved (clawed) than in var. venenosum. It is found in the Pacific Northwest, Colorado, Canada, and the northern plains, much more widely spread than the other variety. Toxicoscordion venenosum var. venenosum The autonymic variety almost never has branches on its flowering stem, at most having just one branch. The outer tepals of the flowers are clawed and 5 millimeters long. It it found on the west coast of North America from British Columbia to Baja California in Mexico. It is not found further east than Nevada, Idaho, or Utah. In English it is often simply called "death camas", a name also applied to other species in the genus. More specifically it is known as "meadow death-camas" to distinguish it from other related plants. The variety gramineum is sometimes called "grassy deathcamas". The "camas" part of its name is due the resemblance of the bulbs to those of the edible Camassia flowers. Other common names include "poison onion" and "poison camas". In the Northern Pomo language all members of the genus including this species are called "tsim’bu" meaning "harmful bulb". Likewise in the Umatilla language from along the Columbia River this species is called "alapíšaš", but the related Toxicoscordion paniculatum and even Anticlea elegans may have also been called by this name. In the Ktunaxa language of British Columbia it is called "nupqasaquǂ" ("nup-ka-sa-qush"). In the Lushootseed language of South Puget Sound it is called "ba'q'a'". ==Distribution and habitat==

, Wyoming Meadow death camas is found through much of western North America. In Canada it is found in three western provinces: Alberta, British Columbia, and Saskatchewan. In the United States, it grows from the West Coast to the Rocky Mountains (with the exception of Arizona). This includes California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. The meadow death camas grows in more open, sunny habitats. The variety venenosum grows in grasslands and open pine woodlands of the interior from . The variety gramineum grows in well drained grasslands and coastal areas from sea level to as much as . They prefer wet areas, but can grow in much drier habitats than common camas (Camassia quamash) such as on hillsides in the Sierra Nevada. They may also be found in opening in coniferous forests and among the sagebrush of the interior. == Ecology ==

'') in British Columbia The nectar is also poisonous; controlled experiments have shown that honeybees can be fatally poisoned by the flowers, and it or its relative are suspected in a few cases of honeybee poisonings. The plant is visited by a specialist miner bee, the death camas miner bee (Andrena astragali), which is likely the only bee that can tolerate its toxins. In turn the bee is an oligolege, a species that specializes in the pollen of only a few species of flower. The death camas miner bee specializes in meadow death camas and the closely related Toxicoscordion paniculatum. Seed production for the plant is also significantly increased by bees visiting the flowers. Theories as to what advantages specialization and toleration of the toxicity of the nectar and pollen provide include that the lack of competitors for the food resources provided by the flowers and that, as with the monarch butterfly, ingesting toxic food protects the bees from predators and parasites by making them toxic. As a bulb plant, it survives fires easily. Though plants that are actively growing will be consumed in a fire the bulb will survive and regenerate. When dormant the bulbs are apparently entirely unaffected by fires. They grow in a variety of habitats with different fire intervals, from as infrequent as more than 400 years between fires to as frequent as yearly fires in some ponderosa pine forests. == Conservation ==

When evaluated by NatureServe in 2015 it was found to be "Secure" at the global level (G5). They also found it to be secure in British Columbia, Montana, and Wyoming (S5) and "Apparently Secure" (S4) in the provinces of Alberta and Saskatchewan. == Toxicity ==

Toxicoscordion venenosum has a well-deserved poisonous reputation. While they are not easily confused with other species while in bloom they can easily be mistaken for edible bulbs like those of the camas lily in the Pacific Northwest once the leaves and flowering stems have faded. The plant is also deadly to livestock, with sheep being most commonly poisoned. The lethal dose of green plant material is between 0.6% and 6.0% of an animal's body weight. In experiments with sheep it was among the most poisonous of members of its genus with just 0.4% of green material by body weight causing symptoms, close to the 0.2% of Toxicoscordion nuttallii. And material from T. venenosum var. gramineum was almost as equally fatal at just 0.6% compared with 0.5% for T. nuttallii. As a plant develops towards flowering the levels of zygacine decrease in the plant. The plants tend to have higher levels of poison in dry locations and in years with less rainfall. == Uses ==

Traditional uses Though well aware of the poisonous nature of the plants, the indigenous Paiute people have made use of crushed bulbs as poultices for a range of ailments in an identical manner to Toxicoscordion paniculatum, which they called by the same name. It was used for burns, rattlesnake bites, rheumatism, and swellings. The naturalist Ira Noel Gabrielson dismissed the species and all of its relatives (except for Toxicoscordion fremontii) as a cultivated plant due to lacking "charm enough to take up room in a garden when so many more beautiful things are available". Despite this, the species is occasionally grown in wildflower meadows or perennial borders for its spring flowers in either full sun or partial shade. Due to the toxic nature of it and all its relatives, caution is urged to avoid planting it where herbivores would have access. In the Manual of Bulbs from the Royal Horticultural Society it is listed as tolerating winter temperatures at least as cold as . It is hardy in USDA zones 3b–9b. ==References==