A trip to Kissimmee Prairie State Park today revealed beautiful Sesbanias to be the plants of the day John and George stopped the car to check on Danglepod, Sesbania herbacea, in a roadside ditch near the park. This species is probably native, although perhaps a little too weedy and widespread for its exact origins to be clear. The pod is long and skinny, in contrast with today’s featured species below, and the standout feature is underground, or better put, under water. The root mass looks like Santa’s beard, a bleached-white spongy mop studded with nitrogen-fixing nodules on steroids slurping nutrients so aggressively out of the stinky canal water you could almost hear it. If you ever need a plant to sop nutrients out of eutrophic water, here’s a candidate—or do all those nitrogen-fixing nodules put nitrogen back in? A water-lover for sure. Various species of Sesbania have “river hemp” as part of their names.
Being fast-growing, tolerant of hard times, and nitrogen-fixing, species of the large genus Sesbania have worldwide roles as green manures, fodders, and similar applications, although the seeds (and other parts?) are toxic. They are also showy, which no doubt is why Sesbania punicea with flame-colored flowers and winged pods has escaped cultivation to become a Category II invasive exotic in Florida and beyond. Why does somebody always have to sell every #$%^ weed with colorful flowers? And why does every species of Sesbania have its own weird pod?
Colorizing the lonesome prairie is Sesbania vesicaria with three-toned blossoms in lively salmon red shaded with deep maroon and with a sunny yellow eye. You can’t miss them. The name Bladderpod is self-explanatory upon encountering the bladder, and is reflected in the species name “vesicaria,” which means puffed up. Vesicants cause blisters. The mature legume is puffy, bloated, pointy at the ends, and dangling decoratively. Confession time: having seen the bladder dangling on bare twigs in the off-flowering months, the identity was not obvious until leaves and flowers illuminated the pretty truth. The pod could pass for a large insect pupa, except for being full of seeds.