*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.

Cupania glabra Sw.

American toadwood

South Florida Status: Critically imperiled. Three occurrences in two conservation areas (National Key Deer Refuge; Great White Heron National Wildlife Refuge), and one non-conservation area (Cupania Hammock).

Taxonomy: Dicotyledon; Sapindaceae.

Habit: Tree.

Distribution: Native to South Florida, the West Indies, and Central America.

South Florida Distribution: Monroe County Keys.

South Florida Habitats: Rockland hammocks.

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

Aids to Identification: Scurlock (1987) has color photos; Nelson (1994) has a color photo; Nelson (1996) has a color photo; Chafin (2000) has illustrations and a color photo.

References: Small, 1933a; Long & Lakela, 1976; Little, 1978; Ward, 1978; Tomlinson, 1980; Scurlock, 1987; Nelson, 1994; Nelson, 1996; Wunderlin, 1998; Chafin, 2000; Coile, 2000.

Synonyms: None.

Historical Context: John Loomis Blodgett first collected American toadwood between 1838 and 1853 on Big Pine Key (Blodgett s.n., NY). Blodgett’s specimen was unidentified until Nathaniel L. Britton studied the specimen and determined it to be Cupania glabra (Britton, 1901). It was not rediscovered until 1921 when Charles Torrey Simpson found it on Big Pine Key (Small, 1924). It was vouchered later that year by John Kunkel Small and others (10198, NY). T. Ann Williams observed plants on Big Pine Key from the 1970s through the 1990s (personal communication, 6 March 2001). American toadwood is present on Big Pine Key at Watson Hammock in National Key Deer Refuge. Ellsworth P. Killip made the first collection that can be definitely attributed to this station in 1951 (40877, US). Several other collections were made from Watson Hammock including one by Steven R. Hill in 1984 (13387, NY). Bradley and Woodmansee observed plants there in 2001.

The next station to be discovered was at Cupania Hammock, a privately owned site on Summerland Key, where George N. Avery found a few plants in 1964 (Avery’s Notes, 27 September 1963). Robert W. Long vouchered this station in 1967 (2470, USF). According to Kruer (1992), it is common here and this is the second largest population in the Keys, after Watson Hammock.

In 1965, a few plants were found by Lois and Stan Kitching on Johnston Key in the Great White Heron National Wildlife Refuge (Avery’s Notes, 20 February 1965). Avery observed a few plants at this station later that year. Kruer (1992) reported three small trees at this site. American toadwood is assumed to be extant at this station, but needs to be vouchered.

Major Threats: Habitat destruction; exotic pest plant invasions; sea-level rise.

Recommendations: • Voucher plants at Johnston Key. • Map and monitor known stations on a regular basis. • Acquire Cupania Hammock.