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.
Enjoy the Oslo Riverfront Conservation Area 