*The following is based on Gann, G.D., K.A. Bradley & S.W. Woodmansee. 2002. Rare Plants of South Florida: Their History, Conservation, and Restoration. The Institute for Regional Conservation: Miami. For updated species accounts, see Citation below. For the original text, follow the link in the Update field. If no Update field is displayed, then cite as the original publication.

Schizachyrium sericatum (Swallen) Gould

Silky bluestem


South Florida Status: Critically imperiled. One occurrence on a roadside on Ramrod Key.

Taxonomy: Monocotyledon; Poaceae.

Habit: Perennial terrestrial herb.

Distribution: Endemic to South Florida.

South Florida Distribution: Monroe County Keys.

South Florida Habitats: Original habitat unknown, but possibly in pinelands, openings in hammocks, or on coastal berms. Now confined to a single roadside.

Protection Status: Listed as endangered by FDACS and as critically imperiled by FNAI.

Aids to Identification: Hitchcock & Chase (1950) has an illustration.

References: Swallen, 1941; Hitchcock & Chase, 1950; Hall, 1978; Avery & Loope, 1980a; Wunderlin, 1998; Coile, 2000.

Synonyms: Andropogon sericatus Swallen.



Historical Context: W.A. Silveus first collected silky bluestem in 1940 on Ramrod Key (6633, US). This collection was designated as the type specimen when Jason R. Swallen described it as a new species in 1941. No habitat data was specified. It was not seen again until 1995, when Bradley made two collections on roadsides on Ramrod Key (269, FTG; 278, FTG). Fewer than 50 plants were seen. This species was erroneously reported for Key Largo (Hall, 1978).

Major Threats: Mowing; herbicide applications; dumping.

Comments: This is one of the state’s most imperiled plant species. It will be under constant threat of extinction until a population is established within an appropriate habitat in at least one conservation area.


Recommendations: • Survey additional areas on Ramrod Key, including the Ramrod Key Coastal Berm Site. • Map and monitor plants at least annually. • Develop conservation agreement with Monroe County to insure that maintenance personnel do not accidentally kill the Ramrod Key population. • Conduct conservation biology and conservation horticulture studies. • Consider establishing an ex situ collection of germplasm. • Assess appropriateness and study feasibility of introducing silky bluestem to other sites within its historical range, including Ramrod Hammocks, Florida Keys Wildlife and Environmental Area. • Review for listing by USFWS.