Smooth rattlebox is an odd looking perennial member of the legumes. It caught my eye immediately. Like most legumes, it’s good for the soil and makes good compost. Unlike the other members of the crotalaria genus, this one is considered somewhat edible…I think.
Wikipedia claims the flowers can be eaten and the seeds used in two ways: fermented or roasted & boiled. Of course, I always take Wikipedia with a large lump of salt, so I went looking for original sources. Wild South Florida has almost the same information, but no citation. The Wikipedia citations lead to an Australian publication and a French publication. Je ne parle pas français. Anyone want to help?
The Australian publication states
The species is suspected of being poisonous to stock, the foliage containing a toxic alkaloid which is lost when the plant is dried. The seeds have been used as a coffee substitute, and although they contain an alkaloid, they may be eaten after careful preparation. The half-ripe seeds are boiled for 2 hours, washed, wrapped in a banana leaf and left to ferment for a couple of days, subsequently being used, either directly or fried, as a flavouring for rice. It has also been used as a green manure on tea and rubber plantations.DuPuy, D.J. & Telford, I.R.H. (1993) Flora of Austalia 50 Oceanic Islands 2: p236