Hecastocleis shockleyi

Hecastocleis shockleyi
	Hecastocleis shockleyi , inflorescence with flower heads
Systematics
	Euasterids II
Order :	Astern-like (Asterales)
Family :	Daisy family (Asteraceae)
Subfamily :	Hecastocleidoideae
Genre :	Hecastocleis
Type :	Hecastocleis shockleyi
Scientific name of the subfamily
	Hecastocleidoideae
	Panero & Funk
Scientific name of the genus
	Hecastocleis
	A.Gray
Scientific name of the species
	Hecastocleis shockleyi
	A.Gray

Hecastocleis shockleyi is the only species of the monotypical plant genus Hecastocleis and alone forms the subfamily Hecastocleidoideae in the sunflower family (Asteraceae).

description

illustration

Vegetative characteristics

Hecastocleis shockleyi grows as a shrub or shrub with stature heights of usually 40 to 80 (rarely more than 150) centimeters. Hecastocleis shockleyi forms runners ( stolons ) and has deep roots. The bark is initially light green, then becomes whitish-brown and finally ash-gray to brown. The trichomes (hairs) are simple and white. There are mostly tufts of hair in the leaf axils.

The alternate leaves are sessile. The simple leaf blade is linear with a length of 1 to 4 centimeters . The leaf base is wedge-shaped and more or less encompassing the stem. The leaf surface is tomentose hairy to bald. The thickened leaf edge is smooth or reinforced in the lower area with three to six thorns.

Generative characteristics

The flowering period extends from April to June. One to five cup-shaped inflorescences of the first order are grouped together in cup-shaped inflorescences of the second order (double basket). The second-order inflorescences have a diameter of 15 to 25 millimeters and are surrounded by egg-shaped to rounded, reinforced bracts . The 20 to 30 unequal, egg-shaped to lanceolate bracts are in two to five rows. The inflorescence base is flat and hairless. Each first-order flower head contains only one flower. The radially symmetrical flower is hermaphrodite. The five initially reddish purple, later greenish white, smooth petals are fused tubular and about 10 millimeters long. The five corolla lobes are about the same length as the corolla tube. The five stamens are purple to light pink in color. The two branches of the style are relatively thick with a diameter of 0.1 to 0.5 millimeters.

The brown to black, smooth achenes are more or less flattened, indistinct four to five nerves and 5 millimeters in size. The 1 to 2 millimeter large pappus consists of only six unequal scales that have a smooth or multi-toothed edge; sometimes they form a torn wreath.

The basic chromosome number is x = 8; there is diploidy with a chromosome number 2n = 16.

Distribution of Hecastocleis shockleyi

Occurrence

The home of Hecastocleis shockleyi is in the southwestern United States . Hecastocleis shockleyi owns areas in southwestern Nevada and adjacent areas in California . In arid regions, Hecastocleis shockleyi grows at altitudes of 1700 to 2000 meters. It thrives in areas over granite or basalt and with "caliche" soils (soils with hard limestone crusts). It also grows directly in rocks or highly drained soil.

Systematics

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

literature

The subfamily in the Asteraceae family on the AP website. (English)
Beryl B. Simpson: Hecastocleis. In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico . Volume 19: Magnoliophyta: Asteridae, part 6: Asteraceae, part 1 (Mutisieae – Anthemideae). Oxford University Press, New York / Oxford a. a. 2006, ISBN 0-19-530563-9 , pp. 71 (English). , online.
Jose L. Panero, Vicki A. Funk: Toward a phylogenetic subfamilial classification for the Compositae (Asteraceae). In: Proceedings of the Biological Society of Washington. Volume 115, No. 4, 2002, pp. 909-922, online .

Individual evidence

↑ ^a ^b ^c ^d ^e Beryl B. Simpson: Hecastocleis. : In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 19-21, New York and Oxford: Hecastocleis shockleyi , p. 71 - online with the same text as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 19: Magnoliophyta: Asteridae, part 6: Asteraceae, part 1 (Mutisieae – Anthemideae). Oxford University Press, New York and Oxford 2006, ISBN 0-19-530563-9 .

Web links

Commons : Hecastocleis shockleyi - collection of images, videos and audio files

Jose L. Panero: Hecastocleidoideae: Hecastocleis shockleyi , April 4, 2008 version in The Tree of Life Web Project. (English)

[FoNA-1] Beryl B. Simpson: Hecastocleis. : In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico , Volume 19-21, New York and Oxford: Hecastocleis shockleyi , p. 71 - online with the same text as the printed work , In: Flora of North America Editorial Committee (Ed.): Flora of North America North of Mexico. Volume 19: Magnoliophyta: Asteridae, part 6: Asteraceae, part 1 (Mutisieae – Anthemideae). Oxford University Press, New York and Oxford 2006, ISBN 0-19-530563-9 .