Asclepias humistrata

Common name: Pinewoods Milkweed; Sandhill Milkweed

Asclepias humistrata
Asclepias humistrata
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta - Flowering plants
Class:	Dicots
Order:	Gentianales
Family:	Apocynaceae
Genus:	Asclepias
Species:	A. humistrata
Binomial name
Asclepias humistrata Walter
Natural range of Asclepias humistrata from USDA NRCS [1].

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).

More specifically, for A. humistrata, the stems are glabrous, simple, stout, and rarely solitary; they spread ascendingly, and grow 2-7 dm tall. The leaves are opposite, about 5-8 pairs, ovate in shape, and 6-10 cm long, 4.5-8.5 cm wide. The leaves are widely acute to obtuse, the margins are flat, auriculate, more or less amplexicaul, subsucculent, glaucous, the veins are pink to lavender in color, and are sessile. There are 2-5 or more umbels beginning from the upper 2-5 nodes, and are 3-5 cm broad. The corolla is pale rose or lavender in color, the lobes are reflexed, and are 5-6.5 mm long. The corona is 3-5 mm in diameter. The horns are shorter than the hood. The follicles are erect and are 9-14 cm long, 1.3-1.8 cm broad. Flowers May to June; June to July. (Radford 1964).

Ecology

Habitat

In the Coastal Plain in Florida and Georgia, A. humistrata can occur in scrub oak sand ridges, longleaf pine-scrub oak ridges, pine-palmetto thickets, turkey oak scrubs, low sand dunes, and mixed pine hardwood associations. It can occur in disturbed areas such as sandy fallow fields and roadsides (FSU Herbarium). Associated species include Coreopsis basalis, Hymenopappus scabiosaeus, Liatris, Panicum, Leptoloma cognatum, Q. laevis, Q. incana, Q. geminata, Aristida stricta, Vaccinium stamineum, V. myrsinites and Licania michauxii (FSU Herbarium). Soil types include loamy sand and coarse sand (FSU Herbarium).

Phenology

Flowers March through October and fruits April through October (FSU Herbarium).

Fire ecology

It has been observed growing in burned over, longleaf pine forests (FSU Herbarium).

References and notes

Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: November 2015. Collectors: Loran C. Anderson, M. Boothe, Edwin L. Bridges, Richard Carter, Jack P. Davis, Elmer, J.P. Gillespie, Robert K. Godfrey, R.D. Houk, Lisa Keppner, Gary R. Knight, Robert Kral , H. Larry, Robert L. Lazor, Karen MacClendon, Sidney McDaniel, R.A. Norris, Steve L. Orzell, C. Prichard, Grady W. Reinert, Annie Schmidt, E. Stipling, D.B. Ward, S.J. Ward, Rodie White, Mary Margaret Williams, Jean W. Wooten. States and Counties: Florida: Baker, Bay, Calhoun, Clay, Dixie, Escambia, Franklin, Gadsden, Gilchrist, Hamilton, Jackson, Leon, Levy, Liberty, Marion, Nassau, Okaloosa, Pasco, Polk, Santa Rosa, Taylor, Volusia, Wakulla, Washington. Georgia: Grady. Compiled by Tall Timbers Research Station and Land Conservancy.

Radford, Albert E., Harry E. Ahles, and C. Ritchie Bell. Manual of the Vascular Flora of the Carolinas. 1964, 1968. The University of North Carolina Press. 848-852. Print.