Asclepias verticillata
| Asclepias verticillata | |
|---|---|
| |
| Photo taken by Gil Nelson | |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta - Flowering plants |
| Class: | Magnoliopsida - Dicotyledons |
| Order: | Gentianales |
| Family: | Asclepiadaceae |
| Genus: | Asclepias |
| Species: | A. verticillata |
| Binomial name | |
| Asclepias verticillata L. | |
| |
| Natural range of Asclepias verticillata from USDA NRCS Plants Database. | |
Common names: Whorled Milkweed
Contents
Taxonomic notes
Description
In general, with the Asclepias genus, they are perennial herbs usually milky sap. The stems are erect, spreading or decumbent and usually are simple and often solitary. The leaves are opposite to subopposite, are sometimes whorled, and rarely alternate. The corolla lobes are reflexed and are rarely erect or spreading. The filaments are elaborate into five hood forming a corona around the gynosteguim. The corona horns are present in most species. (Radford 1964).
Specifically, for A. verticillata, the stems are simple or there is branching in the upper third portion. Grows approximately 3-8 dm tall and is pubescent in lines. There are numerous leaves that are whorled or subverticillate, are linear, and grow to be 3-7 cm long and 1-2 mm wide. The leaves are pubescent or glabrate and usually revolute. There ae 2-8 umbels coming from the upper nodes, they are 2.2-5 cm broad. The peduncle is 1.5-2.5 cm long. The corolla is greenish white in color. The lobes are 3.5-4.5 mm long and have rose-purple tint at the tip of the lobes. The corona is 3-5 mm in diameter. The acicular horns are exserted. The follicles are erect and are 4.5-8.5 cm long and 4-6 mm broad. Flowers June to September; September to October. (Radford 1964).
Distribution
It is found from Massachusetts, south to Texas, east to Florida, and west to Arizona (Weakley 2015).
Ecology
Habitat
Native upland pine and pine-hardwood communities, loblolly pine plantations (Ultisols), borders of wetland depressions within pine communities, sandhills and sand ridges, (Entisols), open calcareous glades, bluffs along Apalachicola River (FSU Herbarium). It can be found in bluestem prairie (Hover and Bragg 1981). It increases with spring burning (Hover and Bragg 1981). It is a warm-season grass (Hover and Bragg 1981). Can occur in areas with soil disturbance (FSU Herbarium). Thrives in frequently burned areas and flowers within two months of burning in the growing season (Robertson observation). Tolerates full sunlight to partial shade. Tolerates moist to xeric conditions but seems to be limited to sandy or calcareous soil. Found barrens of thin soils of rock outcrops (mafic rocks), also in woodlands and sandhills (Weakley 2015) and in flatwoods (Wunderlin and Hansen 2011).
Associated species include Pinus palustris, Quercus laevis, Q. margaretta, Q. rubra, Tragia, Setaria, Panicum, Hedyotis, Euphorbia floridana, Gaillardia aestivalis, Rhynchospora globularis, Pteridium aquilinum, Polianthes, Fraxinus, Melanthera nivea, sweetgum, poison oak, mockernut hickory, and others (FSU Herbarium).
Phenology
It flowers and fruits from April to September (FSU Herbarium; Weakley 2015). It resprouts and flowers within a few weeks of being burned from early spring through summer, but it also flowers in years when it is not burned up to at least five years following fire, primarily in July and August in northern Florida and southern Gerogia (KMR[1]).
Seed dispersal
Asclepias verticillata has seed pods that extend vertically from meristems near the top of the stem. Seeds are dispersed by wind after pod dehiscence. Seeds are up to 4 mm in diameter but have a large white coma facilitating distant seed dispersal (KMR[2]).
Seed bank and germination
Fire ecology
Pollination
Use by animals
Diseases and parasites
Conservation and Management
Cultivation and restoration
Photo Gallery
References and notes
Robertson data. Dataset compiled at Pebble Hill Fire Plots from 2005 to 2015.
Hover, E. I. and T. B. Bragg (1981). "Effect of season of burning and mowing on an eastern Nebraska Stipa-Andropogon prairie." American Midland Naturalist 105: 13-18.
Weakley, Alan S. Flora of the Southern and Mid-Atlantic States: Working Draft of 21 May 2015. University of North Carolina Herbarium (NCU). PDF. 933.
Wunderlin, Richard P. and Bruce F. Hansen. Guide to the Vascular Plants of Florida. Third edition. 2011. University Press of Florida: Gainesville/Tallahassee/Tampa/Boca Raton/Pensacola/Orlando/Miami/Jacksonville/Ft. Myers. 271. Print.
