The Partridge Pea
MISSOURI NATIVE SPECIES | August 25, 2020
While jogging through my favorite native grassy field, I noticed a little pop of yellow well-hidden behind some other tall grasses. I stopped to observe a delicate and floppy little flower, and later learned it is actually a native legume! Up next in my Missouri Native Species Collection is the vibrant and cheerful Partridge Pea plant.
Characteristics of the Partridge Pea
Chamaecrista fasciculate, commonly known as the Partridge Pea, is a showy hermaphroditic annual that blooms from June through September. Standing erect at 1-3 feet tall, flowers grow stacked along the vertical stem. Each flower contains five rounded petals and ten stamen. Extrafloral nectaries on the leaf stems produce the plant’s nectar, as opposed to the flower itself. While the Partridge Pea grows upright it tends to sprawl outwards in bunches, creating a thicket-like shelter for small animals.
I find the plant’s fern-like leaves particularly interesting. Growing in a pinnate-compound fashion, leaves are attached to both sides of the rachis (extended petiole). When touched the tiny leaves will usually curl upward giving way to another common name, the Sensitive Plant.
Self-Seeding and Erosion Control
The Partridge Pea is hermaphroditic and therefore self-seeds. This method does not require human nor animal intervention and is considered to be an invasive method of reproduction as it can multiply very quickly. Needing very little assistance and maintenance from the outside world, this is a plant that stands well on its own.
Being so prolific does have its advantages to the environment. Farmers and gardeners often plant Partridge Pea in disturbed areas to improve both soil quality and combat erosion.
Because the plant has a tendency to sprawl outward, Partridge Pea is considered a great cover crop. Sprawling outward creates thickets of plants that aid in erosion control and bank stabilization.
Biological Nitrogen Fixation
Farmers and gardeners also plant Chamaecrista fasciculate to improve soil quality. Legumes like the Partridge Pea possess a symbiotic relationship with bacteria in the soil. As bacteria feed gaseous nitrogen from the soil to the legumes, the legumes in turn offer carbohydrates to the bacteria. This special, mutually beneficial relationship works to “fix” nitrogen levels in the surrounding soil. To read more technical information about the process, you can visit this interesting article by New Mexico State University: https://aces.nmsu.edu/pubs/_a/A129/
An Important Source of Food
Partridge Pea provides a source of honey nectar for insects. Interestingly the plant’s nectar is not located in the flower, but rather in small orange glands located at the base of each leaf. Produced by glands in extrafloral nectaries, the nectar also attracts sweat bees, flies, and wasps in addition to pollinators.
The Partridge Pea not only provides nectar; the plant’s seeds are a crucial staple in the diet of the Alabama bobwhite quail (hence the name, “partridge”). In early Autumn plants will develop highly coveted seed pods. Because the seeds are present throughout the wintering months, it provides a dependable and necessary food source for field mice, mallards, and other prairie birds and waterfowl.
Chamaecrista fasciculate is a hardy, resilient and independent plant that thrives across a variety of mediums. As a native legume, Partridge Pea is an effective combatant of soil erosion, a champion of nitrogen fixation, and provides an important food source for a variety of birds and small mammals.
I will have to visit this plant again in the early Fall season, to observe its very important seed pods.
EDIT: Image of seed pods added in after a return visit.
Sources: Missouri Department of Conservation, Missouri Botanical Garden, United States Department of Agriculture, New Mexico State University.
Technical: Canon 5D mk4 + 100mm f/2.8L, Fujifilm x100V