Amianthium

Amianthium muscitoxicum blooms between May and July with small white flowers that turn greenish or purplish with age.^[8] Its flowers form an indeterminate bracteate raceme inflorescence.^[11] It blooms from the bottom of the inflorescence upwards, eventually forming small, bright orange fruits in the late summer or fall.^[12]

A. muscitoxicum can grow 1–4 feet tall.^[8] Its main leaves are at the base of the plant; they are thin and can grow more than 12in long.^[8] It also has leaves along the length of the stem, but they are very reduced.^[8]

Amianthium muscitoxicum is native to the eastern United States from New York to Florida and can be found as far west as Missouri and Oklahoma.^[5] Its native habitats include oak forests, bogs, low pinelands, savannas, meadows, and sandhills.^[7]

It does best in partial shade, with 1–2 hours of direct sunlight.^[12] Companion plants include: longleaf pine, willow oak, mountain laurel, blueberries, galax, heartleaf, foamflowers, smilacina, Soloman's seal, dwarf iris, jack-in-the-pulpit, black cohosh, grasses.^[12]

Amianthium muscitoxicum is self-incompatible and is mainly pollinated by five species of beetle, predominantly Strangalepta abbreviata.^[13][14] These beetles are rewarded by nectar produced within each flower, with beetles spending significantly more time at flowers with higher nectar volumes.^[14]

A. muscitoxicum exhibits partial dichogamy, meaning there is a separation in the timing of male and female reproductive function.^[11] Specifically, it is protandrous, which means that the pollen is produced before the stigma becomes receptive to other pollen.^[11] Nectar production varies with the sexual phase of each flower, accumulating through the lifecycle and peaking just after anthesis, when the flower blooms and is functional.^[14] This species has a high potential for multiple mating, which generally increases fitness due to greater genetic diversity of seeds and a higher likelihood of a compatible cross.^[15]

Amianthium muscitoxicum contains toxic alkaloids, and as such, is highly poisonous when ingested to livestock, humans and other animals.^[7] Four toxic alkaloids, which are similar to neurotoxins,^[7] have been isolated from the plant: jervine, two unknown ester alkaloids, and amianthine.^[16] These alkaloids are found in all parts of the plant, with especially high concentration in the bulbs.^[9]

Historical experiments tested the toxicity on sheep and cattle.^[17] Observed symptoms included cessation of eating and excess production of saliva, nausea followed by vomiting, rapid pulse, rapid and irregular respiration, weakness, and difficulty walking.^[17] When fatal, death occurred in about an hour.^[17] This is the origin for "stagger grass" as a common name for this plant.^[7]

Amianthium muscitoxicum's common name "fly poison," comes from its use by early colonists as a way to control flies.^[12] The bulbs can be ground down and mixed with something sweet, such as molasses or honey, to attract flies.^[17] When flies drink it, they become unstable and have difficulty moving.^[17] After 24 hours or so, if the flies have not been removed, the poison will wear and off and they are seemingly fine.^[17]

Amianthium muscitoxicum is a member of the family Melanthiaceae and the tribe Melanthieae.^[2] Melanthieae contains seven genera, including Melanthium and Amianthium.^[6] A. muscitoxicum, sometimes spelled muscaetoxicum,^[8] was first classified in the genus Melanthium by Thomas Walter in 1788.^[10] More recent molecular and genetic research has firmly classified it in the genus Amianthium, which is characterized by a unique alkaloid that it contains: amianthine.^[18] A. muscitoxicum is the only species within this genus.^[6] (See also Phylogeny of Melanthieae.)

Amianthium species which have been placed in other genera include:^[2]

• Amianthium angustifolium A.Gray now called Stenanthium densum (Desr.) Zomlefer & Judd
• Amianthium aspericaule A.Gray) now called Triantha glutinosa (Michx.) Baker
• Amianthium leimanthoides A.Gray) now called Stenanthium densum (Desr.) Zomlefer & Judd
• Amianthium nuttallii A.Gray now called Toxicoscordion nuttallii (A.Gray) Rydb.
• Amianthium texanum (Bush) R.R.Gates now called Stenanthium densum (Desr.) Zomlefer & Judd