April Plant of the Month - Partridge Pea

By Laurie Sheppard

Partridge Pea is a valuable member of the Leguminosae (Pea) family. From the bottom up, it returns nitrogen to the soil, provides nectar for crawling insects as well as to pollinators, and food for butterfly larvae. Its seed pods are eaten by grassland birds and field mice and occasionally, by deer. It can be planted along roadsides and stream banks to control soil erosion and often grows in dense stands that produce litter and plant stalks to furnish cover for upland birds, small mammals, and waterfowl. It is considered an important honey plant as it frequently grows where few other honey plants are available. It has also been used as a medicinal by Native Americans to quell nausea or to combat fainting spells, although, in large amounts, it can be toxic.

Sensitive Plant or Sleeping Plant are other names by which the Partridge Pea is known. It earns those alternates, not by its effects on wildlife or humans but because when lightly touched, the Partridge Pea’s leaves will fold in on themselves. They also fold shut at night, hence the name “Sleeping Plant”. The leaves are pinnate, which means each stem that extends from the stalk is a single leaf and the narrow, inch-long, blue-green structures extending from the stem are called leaflets. There are 5-18 pairs of leaflets on each leaf, staggered alternately along the leaf stem.

Partridge Pea Emerging, by Laurie Sheppard

Partridge Pea produces small clusters of yellow flowers, each an inch across with five equal petals, and blooms from summer to fall throughout most of the eastern United States. Each flower has a bright red blotch at its base and features two types of anthers, which are the pollen-producing structures of the flower. Yellow anthers produce reproductive pollen while dark red or purple anthers produce food pollen.

Photo credit: Space Coast Wildflowers

One of the more unusual characteristics of the Partridge Pea is the presence of small nectar-producing glands on the leaf stalks called nectaries. It is here that nectar feeders congregate, leaving the blooms to be pollinated by long-tongued bees seeking food pollen. Those nectaries also attract ants and other crawling and flying insects looking for a free lunch.

Nectarie on Partridge Pea, by Laurie Sheppard

Partridge pea is a short-lived perennial plant that will reseed itself and is a larval and nectar food source for many of our Butterfly Garden’s most common butterflies. Cloudless Sulphur, Sleepy Orange, and Little Yellow butterflies will lay eggs on this plant to produce several broods of butterflies in a single season. Cloudless Sulphur caterpillars, in particular, will feed on both the Partridge Pea’s leaves and its flowers. It is said that you can tell which the caterpillar concentrated on by its color, which may be yellow or green. Late last year, we had Ceraunus Blue butterflies (a south Texas species, normally found in the Rio Grande Valley) visit the Butterfly Garden at Hagerman National Wildlife Refuge and they likely produced at least one brood on our Partridge Pea. Gray Hairstreaks also include Partridge Pea among their many caterpillar food sources.