Desmanthus virgatus (Linnaeus) Willdenow. Phen: (Jan-) Apr-Nov (-Dec). Hab: Longleaf pine sandhills, shell middens, hammocks, scrub, mesquital, disturbed areas. Dist: FL peninsula (north to Levy County); West Indies; nw. LA and c. Texas south through Mexico and Central America to South America. The location in nw. LA (Caddo Parish) is adventive (MacRoberts & MacRoberts 2011b).
Origin/Endemic status: Native
Taxonomy Comments: There is a case to be made for recognizing (at least at varietal rank) two taxonomic entities, but the choice is complicated by the lack of available names with correct application. One entity, the usual one in our region, is decumbent to prostrate, with petiolar gland erect, circular, and < 0.5 mm in diameter, leaflets in 8-16 pairs, and fruits 2-3.5 (rarely to 5 cm) long; this has been called "depressus", but the type of "virgatus" applies to this entity. More tropical and present in our area only as a waif, is an erect shrub (to 1.5 m tall), with a large (> 1 mm long), flattened, sessile, elliptical petiolar gland, 10-20 leaflet pairs, and fruits 3-7 cm long; this has been called "virgatus", but with that epithet accurately applied to the "depressus" entity (see Luckow 1993), this entity is apparently without a name if recognized separately.
Synonymy: = Fl3, K3, K4, Mex, NcTx, WH3, Luckow (1993); > Acuan depressum (Humb. & Bonpl. ex Willd.) Kuntze – S; > Acuan virgatum (L.) Medik. – S; > Desmanthus virgatus (L.) Willd. var. depressus (Humb. & Bonpl. ex Willd.) B.L.Turner – SE3, Tx, Isely (1998); > Desmanthus virgatus (L.) Willd. var. virgatus – SE3, Isely (1998)