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Meet the Natives: Bahama Cassia
Cloudless sulphur butterfly caterpillars (Phoebis sennae) on Bahama cassia (Senna mexicana var. chapmanii)
Bahama cassia is one of Florida’s native cassia species. These native shrubs are members of the pea family (Fabaceae), and typically reach about 4 to 5 feet in height.
The plants bloom several times a year and are considered evergreen in south Florida. Flowers produce showy, five-petaled yellow flowers, and the leaves are oval and pinnately compound. Because they are members of the pea family, their fruits resemble those of a typical bean pod.
“Bahama cassia are excellent pollinator plants, as the showy yellow flowers attract a variety of native pollinators,” said SCCF Native Landscapes & Garden Center Assistant Sophie Carpenter. “Although the flowers are mainly pollinated by native bees — including, carpenter, sweat, and bumble bees — bahama cassia are also larval host plants for sulphur butterflies, including our native sleepy orange and cloudless sulphur butterflies.”
Bahama cassia has a limited natural range, found mainly in the Florida Keys and Miami/Dade county. Because of this, it is listed as a state-threatened species by the Florida Department of Agriculture and Consumer Services.
Typically, its native habitats are pine rocklands, rocky hammocks, and dunes. Bahama cassia will grow in full sun to part shade, and prefers dry to slightly moist, well-drained soil.
“Something to note when considering these shrubs for your landscape is that they tend to be relatively short lived, oftentimes only living four or five years,” Carpenter said. “However, they grow relatively quickly and self-seed readily, so they can be easily replaced with a new specimen.”
These plants also have a unique adaptation to help ward off caterpillars — they contain glands at the bases of their leaves that attract ants, which then attack caterpillars feeding on their foliage.
For a similar, longer-lived option, Carpenter suggests the native Privet senna (Senna ligustrina).
“The privet senna occupies similar habitats to Bahama cassia, but can tolerate more shade and gets a bit taller, reaching up to 8 feet. It is also an excellent pollinator plant and larval host plant for sulphur butterflies,” she said.
Purchase Bahama cassia at SCCF’s Native Landscapes & Garden Center, open 9 a.m. to 3 p.m. Tuesday through Thursday at 1300 Periwinkle Way, Sanibel, FL.