Asclepias amplexicaulis

Asclepias amplexicaulis
photo by Gil Nelson
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta - Flowering plants
Class:	Magnoliopsida - Dicotyledons
Order:	Gentianales
Family:	Asclepiadaceae
Genus:	Asclepias
Species:	A. amplexicaulis
Binomial name
Asclepias amplexicaulis Sm.
Natural range of Asclepias amplexicaulis from USDA NRCS Plants Database.

Common names: Clasping Milkweed, Sand Milkweed

Description

Weakley (2015) mentions that the aroma of the inflorescence smells of cloves and roses.

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 Asclepias amplexicaulis, the stem are 1-3 from a root crown, simple, stout, erect, 4-10 dm tall and are glabrous. The leaves are opposite and usually in 4-6 pairs, are widely ovate to ovate-elliptic in shape, and are 8-15 cm long and 4-8 cm wide. The leaves are mucronate, crispate, auriculate-clasping, glaucous and sessile. The umbel corona is 5-8 mm in diameter. The horns are 1.5 times as long as the hood that are arching over the gynostegium. The follicles are erect, are 8-14 cm long, and are 1.2-2.3 cm broad. Flowers from May to July. (Radford 1964).

Distribution

It is found as north as New Hampshire and New York, then west to Kansas, south to Texas and Florida (Weakley 2015). In Florida, it’s found in south to central peninsula (Weakley 2015).

Ecology

Habitat

Asclepias amplexicaulis is found on the upper slopes of longleaf pine-wiregrass flatwoods, and in mixed pine-hardwood habitat, open sand pine woodlands, and longleaf pine-oak-wiregrass sandhill communities (FSU Herbarium). It prefers high light levels associated with open woodlands and dry sandy soils such as loamy sand (FSU Herbarium). It can also appear in human disturbed areas like clearings and roadsides (FSU Herbarium).

Associated species include Pinus palustris, Aristida stricta, Quercus laevis, and Baptisia lecontei (FSU Herbarium).

Phenology

It flowers from spring to summer (Wunderlin and Hansen 2011). In Florida, it has been observed flowering in April and May, specifically (FSU Herbarium). Fruiting has been observed in June and July (FSU Herbarium).

Kevin Robertson has observed this species flower within three months of burning. KMR

Fire ecology

It is present in burned areas (FSU Herbarium).

References and notes

Florida State University Robert K. Godfrey Herbarium database. URL: http://herbarium.bio.fsu.edu. Last accessed: June 2014. Collectors: Loran C. Anderson, Robert K. Godfrey, Sidney McDaniel, R. A. Norris, Richard R. Clinebell II, Travis MacClendon, Karen MacClendon, and G. Wilder. States and Counties: Florida: Washington, Franklin, Leon, Okaloosa, Holmes, Wakulla, Calhoun, and Jackson. Georgia: Thomas.

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.

Weakley, Alan S. Flora of the Southern and Mid-Atlantic States: Working Draft of 21 May 2015. University of North Carolina Herbarium (NCU). PDF. 931.

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. 270. Print.