Big caltrop

Appearance

Big Caltrop's ant-attracting, yellowish-cream blossoms at first glance are uninterestingly similar to a host of other five-petaled, yellowish flowered, weedy herbs, mostly members of the Hibiscus Family. Arising at the right of the flower is a pinnately compound leaf with six leaflets.
It's a little unusual for a pinnately compound leaf to bear an even number of leaflets, for usually there's a "terminal leaflet" arising at the tip of the leaf's rachis, making an odd leaflet number. Also, note the form of the two terminal leaflets, something like a cloven hoof. This is one of those rare times when a plant's leaves are more distinctive than the flowers. The fruits, if we had them, would be seen to be covered with blunt tubercles, not sharp spikes as the word caltrop implies.

Naming

Hook & Arn.

Distribution

Greater Caltrop occurs along the coast in the US from South Carolina to Florida, in Mexico, Central America, northern South America and the West Indies.

Behavior

Annual

Habitat

Moist thickets or plains, often in sand or a weed in cultivated ground, mainly near sea level, but also extending to elevations of 1,500 metres

Uses

Young plants - cooked and eaten as a potherb. In some places it's regarded as marginally edible, and has been receiving attention because it's reported to contain the presteroid diosgenin, which means that some would regard it as an herbal Viagra.