Jane Schnee (Class of 2010) identified purple bushbean (Macroptilium atropurpureum) growing up a cabbage palm at the Ansin Tract Conservation Area, before she led a walk for us there on 4/6/2019. This perennial vine with a swollen taproot can grow to be 9′ long and is native to Texas, Mexico, and parts of central American and south America.
It was brought to Florida as a forage plant for cows. If you are a cow, this plant is not a weed but a fabulous food source. But, this plant is a weed in non-grazed areas in the U.S. and even in Australia.
Yes, its flowers are stunning in color — a dark, dark purple — shown below in a photo taken by George Bollis.
Its pods twist open to expel seeds a considerable distance.
Purple bushbean has trifoliate leaves with a densely hairy underside. Its leaflets are slightly lobed.
The genus, Macroptilium, is derived from the Greek words macro (large) and ptilon (feather). The species name, atropurpureum, means very purple.
A related species, phasey bean (Macroptilium lathyroides) grows at the Oslo Riverfront Conservation Area (ORCA), and the derivation of the genus name is more evident in its trifoliate foliage …
Its flowers have a similar shape but are much pinker and lighter in color.
Both of these members of the pea family, Fabaceae, are weedy in habit and should be removed from natural areas.