Asclepias cryptoceras
| Asclepias cryptoceras | ||||||||||||
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Asclepias cryptoceras subsp. cryptoceras in Utah |
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| Scientific name | ||||||||||||
| Asclepias cryptoceras | ||||||||||||
| S. Watson |
Asclepias cryptoceras is a species of silk plants ( Asclepias ) in the subfamily of the silk plants (Asclepiadoideae). It is common in western North America.
description
Vegetative characteristics
Asclepias cryptoceras is a perennial, herbaceous plant . The prostrate to recumbent, simple or directly branched at the base stems are somewhat stiffened, flattened, 10 to 30 cm long and are essentially bare. The leaves are arranged opposite one another on the stem. The leaf stalks are usually hardly developed, but can also be up to about 5 mm long. The simple leaf blades are with a length of 4 to 9 cm and a width of 4 to 8 cm broadly or approximately round with a broadly rounded or slightly heart-shaped base and a rounded or broadly blunt tip. They are bare, gray-green in color and have a waxy coating that can be easily rubbed off.
Generative characteristics
The terminal or laterally at the uppermost nodes ( nodes ) over a barely developed or up to about 7 cm long inflorescence stem, golden inflorescences contain a few to several flowers. The flower stalks are slender, glabrous and up to 4 cm long.
The relatively large flower is hermaphroditic, radial symmetry and five-fold. The five sepals are narrow lanceolate with a length of 6 to 7 mm. The five petals bend back and are greenish to yellowish in color. The corolla lobes are 1 to 1.5 cm long. There are five stamens . The gynostegium is sessile and purple in color. The corolla lobes are deeply hollowed out and have two distinct tips. They are 6 to 9 mm long and thus about the same length as the stylus or even a little longer and firmly attached over the entire length of the stylus. The stylus has a length of 3 to 3.5 mm and a diameter of 4 to 5 mm. The flowering period extends from April to June, depending on the location.
The outside bare follicles stand upright on upright stalks. With a length of 4 to 7 cm and a diameter of 1.5 to 2.5 cm wide, they are spindle-shaped and provided with a short tip. The seeds are egg-shaped with a length of about 1 cm and have a light brown, 1.5 to 2.5 cm long head of hair.
Occurrence
Asclepias cryptoceras is common in western North America . It occurs in the US states of Arizona , Colorado , Nevada , Utah , Wyoming , Oregon , Idaho and California . It occurs at altitudes between 1400 and 1700 meters. It grows there in higher desert-like areas (altitudes around 1500 meters) and in the chaparral .
Systematics
The first description of Asclepias Cryptoceras was made in 1871 by Sereno Watson in Botany , 283, pl. 28, f. 1-4 in Clarence King : United States Geological Exploration of the 40th Parallel , Volume 5. The specific epithet cryptoceras is derived from the Greek words cryptos for hidden and keras for horn and refers to a horn-like structure in the flower.
There are two subspecies of Asclepias cryptoceras :
- Asclepias cryptoceras S. Watson subsp. cryptoceras : It is found in Colorado, Wyoming, California, Nevada, Utah and Arizona.
- Asclepias cryptoceras subsp. davisii (Woodson) Woodson : It occurs in Washington, Oregon, Idaho, Wyoming, California and Nevada.
swell
- Eric Sundell: Asclepiadaceae Milk Weed Family , In: Journal of the Arizona-Nevada Academy of Sciences , 27, pp. 169-187, Tempe, Ariz. 1994: PDF
- Robert E. Woodson, Jr .: The North American Species of Asclepias L. , In: Annals of the Missouri Botanical Garden , 41 (1), pp. 1-211, St. Louis, Mo., 1954 URL
- Jepson Manual Treatment - Asclepias cryptoceras .
Individual evidence
- ^ Asclepias cryptoceras at Tropicos.org. Missouri Botanical Garden, St. Louis
- ↑ a b Rafaël Govaerts (ed.): Asclepias. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved January 3, 2020.