Senna mexicana var. chapmanii (Chapman’s wild sensitive plant)

Senna mexicana (Jacq.) Irwin & Barneby var. chapmanii (Isely) Irwin & Barneby

Cassia chapmanii Isely

Chapman’s wild sensitive plant, Bahama cassia

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Rosidae	Roses, legumes, proteas, dogwoods, hydrangeas, mistletoes, euphorbias, grapes, many more
Order	Fabales	Legumes (pea and bean families)
Family	Fabaceae	Legume family (peas and beans)
Genus	Senna	From the Arabic name Sana
Species	mexicana	Of or from Mexico
var.	chapmanii	For Alvan Wentworth Chapman (1809–99), American physician and pioneering botanist in the study of flora of the American Southeast

About plant names...

Chapman’s wild sensitive plant is native to Miami-Dade County Florida, and the Florida Keys. It is found in pinelands, hammocks, and dunes, in calcarous, sandy, or loamy soils. It is considered a threatened species, due to its limited range.

Plants: Plants reach 3-9' (91-274 cm) in height, producing rounded clumps, with multiple stems.

Leaves: Leaves are even pinnate and alternate. Leaflets are linear to elliptic, and less than 2" (5 cm) long. A gland at the base of each leaflet attracts ants that attack marauding caterpillars, as described in an article in The Florida Entomologist.

Flowers: Flowers are yellow, ½-1" (1.3-2.5 cm) around, with five petals.

Fruits: Shaped like beans, 3-6" (7.6-15 cm) long and about ¼" (6.3 mm) in diameter. They turn brown and persist in the winter.

Online References:

Senna mexicana var. chapmanii on flawildflowers.org

Senna mexicana var. chapmanii at the University of Florida Institute of Food and Agricultural Sciences

Senna mexicana var. chapmanii on florida.plantatlas.usf.edu