Anisocoma is a monotypic genus of flowering plants in the family Asteraceae, containing the single species Anisocoma acaulis, commonly known as the scale bud. The genus is native to the desert regions of the southwestern United States and adjacent Mexico, where it grows in sandy soils and dry washes of the Mojave Desert, Colorado Desert, and California's Owens Valley.
The plant has a distinctive low-growing habit, producing a flat rosette of jagged, lobed leaves that lie close to the ground. From this basal mat it sends up slender stalks reaching up to 20 centimetres (8 inches) tall, each topped by a solitary flower head that blooms between April and June. Flowers are yellow or white with yellow centers, and the frilly ray florets are characteristically rectangular with flat or slightly toothed tips. Like many members of the Asteraceae family, Anisocoma acaulis exudes a milky latex sap when its tissues are cut. Plants grow in colonies and tend to favour sandy, open habitats including desert washes.
The common name "scale bud" derives from the appearance of the closed flower bud, whose overlapping bracts give it a distinctly scaly texture. As the sole representative of its genus, Anisocoma acaulis occupies a unique position within the tribe Cichorieae of the Asteraceae, the large sunflower family that also includes dandelions, chicory, and lettuce.
Etymology
The common name "scale bud" refers to the scaly, overlapping bracts that cover the closed flower bud of Anisocoma acaulis, giving it a notably textured appearance before the flowers open.
Distribution
Anisocoma acaulis is found in the Mojave Desert, Colorado Desert, and Owens Valley of California, with its range extending into Arizona, Nevada, and the Mexican states of Baja California and Sonora. It occupies elevations from approximately 610 metres (2,000 ft) up to about 2,100 metres (7,000 ft).
Ecology
The scale bud grows in colonies in sandy soils and dry desert washes. It blooms from April to June, producing yellow or white composite flower heads attractive to pollinators active during the desert spring season.
