''Allium tribracteatum'', known by the common name Threebract onion, is a species of

wild onion Wild onion can refer to * any uncultivated species in the genus ''Allium'', especially: **''Allium bisceptrum'' ** ''Allium canadense'' ** ''Allium tricoccum'' ** ''Allium validum'' ** ''Allium vineale'' * ''Asphodelus tenuifolius'' * ''Cyperus bulb ...

Jepson Treament, University of California, Berkeley
. accessed 3.20.2013 found in

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

Distribution and habitat

The plant is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

, where it is known only from the slopes of the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

in Tuolumne and Calaveras Counties.Flora of North America v 26 p 269, ''Allium tribracteatum''
/ref>

Description

''Allium tribracteatum'' is a small onion plant producing a stem only a few centimeters long from an oval-shaped

bulb In botany, a bulb is structurally a short stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...

. There are two leaves which are usually much longer than the stem. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

contains up to 30 petite white to purple flowers, each less than a centimeter long.

Tepals A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

are white to pink with red or purple midveins;

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

purple;

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

gray.Torrey, John. 1857. Reports of explorations and surveys : to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean, made under the direction of the Secretary of War 4(5): 148.
/ref> Flowers bloom March to May.

References

External links

* tribracteatum Endemic flora of California Flora of the Sierra Nevada (United States) Natural history of the California chaparral and woodlands Natural history of Calaveras County, California Natural history of Tuolumne County, California Onions Taxa named by John Torrey Threatened flora of California {{Allium-stub