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Floristic Inventory of the Florida Keys Database Online

Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult.

Heteropogon contortus
Copyright by: Frank Ridgley, 2014
Miami Metrozoo

Family: Poaceae

Group: Monocot

Substrate: Terrestrial

Habit: Herb

Perennation: Perennial

Native Range: Southern United States, the West Indies, Mexico, Central America, South America and the Old World.

Map of select IRC data for peninsular Florida

SOUTH FLORIDA Occurrence: Present

SOUTH FLORIDA Native Status: Doubtfully Native

SOUTH FLORIDA Cultivated Status: Not Cultivated

Comments: This is a perennial bunch grass of nearly worldwide distribution between 35º N latitude and 35º S latitude (USDA Plant Fact Sheet). Wunderlin (1998) treated it as native to Florida, and IRC has traditionally done so as well. However, the Flora of North America (2003) suggested that this was "probably native" to the Old World and introduced here, and that view has gained traction over the last decade. The Atlas of Florida Vascular Plants (2015) currently treats it as not native to Florida, but Calflora and USDA PLANTS considers it native to California and other parts of North America. Regardless of the debate about its nativity in North America, Heteropogon contortus is not historically known from the southeastern United States, including Florida. John Kunkel Small's (1933) Manual of the Southeastern Flora did not include it, and A.S. Hitchcock and Agnes Chase's (1950) Manual of the Grasses of the United States listed its range as Texas to Arizona. It was also not included in Robert Long and Olga Lakela's (1971) A Flora of Tropical Florida, but was collected in South Florida as early as 1963 by Frank Craighead (s.n. USF) on Cape Sable in Everglades National Park and in 1968 by George Avery (419A USF) in Miami-Dade County. It appears to be a recent arrival spreading mostly from road edges and railroad rights-of-way, and may not be a native component of the South Florida flora. As such, we are reclassifying this as doubtfully native to South Florida (3 Nov 2015).

FLORIDA KEYS Occurrence: Present

FLORIDA KEYS Native Status: Not Native, Naturalized

Map of select IRC data for the Florida Keys

Florida Keys History and Distribution: Not reported for the Florida Keys by John Kunkel Small in 1913. First collected in 2000 by Keith A. Bradley (2059, FTG) on a roadside on Key Largo. We consider this an introduced weed in the Florida Keys.

Other data on Heteropogon contortus available from :

Heteropogon contortus has been reported from the following conservation area in the FLORIDA KEYS :
Occurrence Native Status
Snake Creek Hammocks, Florida Keys Wildlife and Environmental Area Present Doubtfully Native

Heteropogon contortus has been reported for the following habitat in THE FLORIDA KEYS :
Disturbed Upland

All Images:

Heteropogon contortus
Copyright by: Frank Ridgley, 2014
Miami Metrozoo

Heteropogon contortus
Copyright by: Frank Ridgley, 2014
Miami Metrozoo

Heteropogon contortus
Copyright by: Shirley Denton