Asclepias viridis
Asclepias viridis
Asclepias viridis is a species of the genus milkweed ( Asclepias ) from the subfamily of milkweed plants ( Asclepiadoideae ). It is native to the south central and southeastern United States.
- 5.1 Literature
- 5.2 Notes and references
Features
Appearance, root, stem axis and leaf
Asclepias viridis is a perennial herbaceous plant that sends out new shoots each year from the strong, spindle-shaped " rhizome " and reaches stature heights of 15 to 60 cm. A large plant produces up to ten strong, essentially bare stems that are self erect, ascending or decumbent. You go directly to the rootstock or are unbranched. All parts of the plant but a white milky juice from when they are broken or injured.
The irregularly alternate arranged leaves are divided into petiole and leaf blade. The petiole is relatively short with a length of 3 to 10 mm. The fixed - membranous leaf blades are ovate with a length of 4 to 13 cm and a width of 1-6 cm to oblong - lanceolate with rounded tipped to Spreitenbasis and tipped to open-angle outer end. The leaf margins are often wavy.
Inflorescence and flower
The flowering period lasts from April to August. The Blütenstandsschäfte are 3-6 cm long and sparse, fine - haired fluffy. The umbel-like inflorescences appear singly and terminally on the stem axis, or more commonly arise from several inflorescences on the side of the uppermost nodes present. About ten flowers are close together in the inflorescences, which have a diameter from 7.75 to 12.75 cm. The slender, 1-3 cm long flower stems are sparsely hairy very fine fluffy.
The hermaphrodite flowers are zygomorphic, fünfzählig double perianth. 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 Kronblattzipfel are 1.3 to 1.5 cm long and usually with ascending tips. The corona is purple pink pale. The 4-6 mm long tip of the corona are hood -shaped; they turn up by the stylus head first down, then from about the mid-length back up and the tips are rounded lobe -shaped. The stylus head is broad - truncated cone, about 2 mm long (high) and 2 mm wide.
Fruit and seed
The follicles stand upright on curved stems. The fine fluffy hairy to bald follicles are wide - beaked fusiform to ovate and short with a length of 6 to 13 cm and a diameter of 2 to 3 cm. The seeds are ovate and about 7 millimeters long. The white to tan-colored head of hair is long and 4 cm.
Ecology and Toxicity
Asclepias viridis is like (almost) all Asclepias species toxic. Grazing animals avoid the plants mostly. Still Poisoning of sheep are documented.
Asclepias viridis heard like most other North American species of the genus silk plant for food of the caterpillars of the monarch butterfly (Danaus plexippus). The caterpillars take when eating on the part of the plant cardiac glycosides and store them. The caterpillars are thus unpalatable to birds.
Occurrence
Asclepias viridis is found in the U.S. 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 soil types, the only exception of deep sandy soils and very wet soils. In Texas, they seem to prefer moist loamy soils. Here Asclepias viridis is the most common species of the genus Asclepias.
Taxonomy and Phylogeny
The first publication of Asclepias viridis was performed in 1788 by Thomas Walter.
Some populations of Asclepias viridis have a wide variation in the size and shape of the leaves. Overall, this type is, however, fairly constant, subspecies are therefore not excreted.
According to the phylogenetic analysis by Fishbein et al. 2011, based on noncoding chloroplast DNA sequences is Asclepias viridis, the sister species of Asclepias asperula.