Asclepias viridis
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Asclepias viridis |
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Asclepias viridis is a species of silk plants ( Asclepias ) from the subfamily of the silk plants (Asclepiadoideae). It is native to the south-central and southeastern United States .
features
Appearance, root, stem and leaf
Asclepias viridis is a perennial herbaceous plant that sprouts every year from the strong, spindle-shaped "rhizome" and reaches heights of 15 to 60 cm. A large plant forms up to ten strong, essentially bald stems that are independently erect, ascending, or prostrate. They branch directly on the rhizome or are unbranched. All parts of the plant secrete a white milky sap if they are broken off or injured.
The irregularly alternating leaves are divided into a petiole and a leaf blade. The petiole is relatively short with a length of 3 to 10 mm. The firm-skinned leaf blades are ovate to elongated-lanceolate with a length of 4 to 13 cm and a width of 1 to 6 cm with a pointed to rounded blade base and a pointed to obtuse-angled outer end. The leaf margins are often wavy.
Inflorescence and flower
The flowering period extends from April to August. The inflorescence shafts are 3 to 6 cm long and sparse, with fine, downy hairs. The umbel-like inflorescences stand individually and terminally on the stem axes, or more often several inflorescences arise laterally at the uppermost nodes . About ten flowers are close together in the inflorescences, which have a diameter of 7.75 to 12.75 cm. The slender, 1 to 3 centimeters long flower stalks are sparsely haired, very finely downy.
The hermaphrodite flower is zygomorphic , five-fold with a double flower envelope . The five essentially bare sepals are lanceolate with a length of 4 to 5 mm. The comparatively large, showy corolla is wheel-shaped and pale green. The petal lobes are 1.3 to 1.5 cm long and usually with ascending tips. The secondary crown is pale purple-pink. The 4 to 6 millimeter long tips of the secondary crown are hood-shaped; they bend downwards from the stylus head , then upwards again from about the middle of the length and the tips are rounded and club-shaped. The stylus head is broad-frustoconical, about 2 mm long (high) and 2 mm wide.
Fruit and seed
The follicles stand upright on curved stems. The finely downy hairy to bare follicles are 6 to 13 cm long and 2 to 3 cm in diameter and are spindle-shaped to ovate and short-beaked. The seeds are egg-shaped and about 7 millimeters long. The white to yellow-brown head of hair is up to 4 cm long.
Ecology and toxicity
Asclepias viridis , like (almost) all Asclepias species, is poisonous. Grazing animals usually avoid the plants. Nevertheless, poisoning of sheep has been documented.
Asclepias viridis belongs to the diet of the caterpillars of the monarch butterfly ( Danaus plexippus ) like most other North American species of the genus silk plants . When they eat, the caterpillars absorb the heart glycosides contained in the plants and store them. This makes the caterpillars inedible for birds.
Occurrence
Asclepias viridis is found in the US states of Alabama , Arkansas , Florida , Georgia , Illinois , Indiana , Kansas , Kentucky , Louisiana , Mississippi , Missouri , Nebraska , Ohio , Oklahoma , South Carolina , Tennessee , Texas and West Virginia .
It grows in clearings, prairies , on dry slopes and dry pine wasteland. The plants are found on almost all types of soil, with the exception of deep sandy soils and very wet soils. In Texas it seems to prefer moist loamy soils. Here is Asclepias viridis the most common species of the genus Asclepias .
Taxonomy and Phylogeny
Asclepias viridis was first published in 1788 by Thomas Walter .
Some populations of Asclepias viridis vary widely in the size and shape of the leaves. Overall, however, this species is fairly constant, so no subspecies are eliminated.
According to the phylogenetic analysis by Fishbein et al. 2011, based on non-coding chloroplast - DNA - sequences is Asclepias viridis the sister species of Asclepias asperula .
supporting documents
literature
- Robert E. Woodson, Jr .: The North American Species of Asclepias L. In: Annals of the Missouri Botanical Garden , Vol. 41, No. 1, 1954, pp. 1-211, St. Louis, Mo. URL (pp. 191–193)
- Lee Davis: Green Milkweed Asclepias viridis Walt. Plant symbol = ASVI2. USDA NRCS Plant Guide - PDF
Individual evidence
- ↑ RA Smith, P. Sharko, D. Bolin, CB & Hong: Intoxication of sheep exposed to Ozark milkweed (Asclepias viridis Walter). In: Veterinary and Human Toxicology , Vol. 42, No. 6, 2000, pp. 349-350, PMID 11111941 .
- ↑ Lee Davis: Green Milkweed Asclepias viridis Walt. Plant symbol = ASVI2. USDA NRCS Plant Guide PDF
- ↑ Tonya Van Hook, Myron P. Zalucki: Oviposition by Danaus plexippus (Nymphalidae: Danainae) on Asclepias viridis in northern Florida. In: Journal of the Lepidopterists' Society , Volume 45, Part 3, 1991, pp. 215-21 PDF .
- ↑ United States Department of Agriculture Plants Profile - Asclepias viridis Green Antelopehorn - USDA data sheet with distribution map
- ^ Thomas Walter, J. Frazer, J. Wenman: Flora Caroliniana, secundum Systema vegetabilium Linnæi digesta, characteres essentiales naturalesve et differentias veras exhibens; cum emendationibus numerosis, descriptionum antea evulgatarum adumbrationes stirpium plus mille continens, necnon generibus novis non paucis, speciebus plurimis novisq. ornata. Londini: Sumptibus J. Fraser Prostant venales apud J. Wenman, in Vico vulgo dicto Fleet-street, 1788. Online at www.biodiversitylibrary.org (p. 107)
- ↑ Mark Fishbein, David Chuba, Chris Ellison, Roberta J. Mason-Gamer, Steven P. Lynch: Phylogenetic Relationships of Asclepias (Apocynaceae) Inferred from Non-coding Chloroplast DNA Sequences. In: Systematic Botany , Volume 36, No. 4, 2011, pp. 1008-1023 doi : 10.1600 / 036364411X605010
