Hecastocleis

Hecastocleis shockleyi is the only species of the monotypic genus Hecastocleis alone forms the subfamily Hecastocleidoideae in the sunflower family ( Asteraceae). The genus was erected in 1882 by Asa Gray. The specific epithet honors the American mining engineer and plant collector William Hillman Shockley ( 1855-1925 ).

Description

Hecastocleis shockleyi grows as a shrub or bush with plant height usually 40 to 80 (rarely over 150 ) centimeters. Hecastocleis shockleyi forming processes ( stolons ) and deeply rooted. The bark is initially light green, then whitish- brown and finally ash brown. The trichomes ( hairs) are simple and white. In the leaf axils are usually clumps of hair. The alternate, sessile leaves are simple. The linealische leaf blade is 1 to 4 inches tall. The leaf base is wedge-shaped and more or less amplexicaul. The leaf surface is tomentose hairy to glabrous. The thickened leaf margin is smooth or reinforced in the lower section with three to six spines.

One to five bloom conditions are first order in basket- shaped inflorescences second order combined (double basket). The second-order inflorescences have a diameter of 15 to 25 mm and are surrounded by ovate to rounded, reinforced bracts. The 20 to 30 unequal, ovate to lanceolate bracts are in two to five rows. The inflorescence base is flat and hairless. Each flower heads first order contains only one flower. The radiärsymmetrische flower is hermaphrodite. The five initially reddish purple, later greenish white, smooth petals are fused Roehrig and about 10 mm long. The five Kronlappen are about equal in length to the corolla tube. The five stamens are purple to light pink. The two style branches are relatively thick (0.1 to 0.5 mm). The flowering period extends from April to June.

The brown to black, smooth achene is more or less flattened, obscurely four - to five annoying and 5 mm. The 1 to 2 mm large pappus consists of only six unequal scales, which have a smooth or multidentate edge; sometimes they form a torn wreath.

Occurrence

The home of Hecastocleis shockleyi is located in the southwestern United States. The species occurs there before in the southwestern Nevada and adjacent areas of California. In arid regions Hecastocleis shockleyi grows at altitudes 1700-2000 meters. It thrives in areas over granite or basalt and " caliche " soils ( soils with hard = lime crusts ). It also grows directly on rocks or very permeable soils.

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