Allium tribracteatum

Common Names

Three-Bracted Onion, Threebract Onion, Three Bracted Onion

Summary

Threebract onion is a California-endemic perennial herb with a bulbous geophyte growth form; a stem only a few centimeters tall arises from an oval bulb, and two leaves are usually longer than the stem. The inflorescence contains 10–30 small flowers, white to purple, with tepals white to pink and red or purple midveins; anthers are purple and pollen gray; flowering occurs from March through May. It is known from Sierra Nevada slopes in Tuolumne and Calaveras Counties and grows on volcanic slopes at elevations around 1300–1900 m (up to about 3000 m).

Conservation status is Global Rank G2 (imperiled) and California Rare Plant Rank 1B.2, reflecting its rarity and restricted distribution in Tuolumne and Calaveras Counties on volcanic slopes; elevation range and endemism highlight the need for habitat protection.

Lifecycle

Perennial

Height

1-3 inches

Sunlight Requirements

Ideally partial shade.

Soil Type

Thin volcanic soils composed of Andocite and Rhyolite.

Bloom Color

White to Purple

Bloom Time

Spring

Leaf Lifecycle

Deciduous

Seasons of Interest

Spring

Attracts Wildlife

Attracts butterflies