Weeds of Wednesday: Flowering Rosary Pea

Good Golly, its flowers are pretty. They stood out on our first post-hurricane IRMA group walk on 10-8-2017 at the Oslo Riverfront Conservation Area (ORCA). Pictured above are the flowers of rosary pea (Abrus precatorius), a Florida Exotic Pest Plant Council (FLEPPC) category #1 invasive species pest plant.

Increased sunlight due to the loss of canopy cover from Hurricane Irma and recent heavy rains have incited this invasive that hails from India to flower in multiple locations at ORCA. Take note of the tiny ants visiting the flowers in the photo above taken where the trail turns to cross the DOT culvert.

Usually, what we notice is the striking pods with their hard-coated red seeds with black eyes that give rise to the common name of crab’s eye …

For many years volunteers have “harvested” the pods to prevent the production of more plants and sought to free other plants from its rampant twining growth. The hard-coated seeds reportedly can last hundreds of years in the soil, unfortunately. Its population at ORCA has been much reduced by these ongoing volunteer efforts.

The seeds, which contain abrin (a substance more poisonous than the poison ricin made famous by Russian spies), were strung together to make rosary beads, bracelets, and necklaces, hence the common name of rosary pea. The species name, precatorious, comes from the Latin word precari, which means “to pray”, and also references this usage of the seeds.

Rosary pea grows quickly, especially when prompted by increased sunlight and water, and can quickly engulf other plants. Somewhere under the morass of rosary pea is a wild coffee (Psychotria nervosa) struggling …

The delicate twining foliage of this vine and its pretty pea-family (Fabaceae) flowers brought this plant into favor to shade porches in the bye gone days before air conditioning.

Its nectar seems to be especially attractive to ants of all sorts, including the (native) Florida carpenter ant (Camponotus tortuganus) pictured above on the trail heading to the Observation Tower. Perhaps, this vine also served to keep ants out of homesteads.