Tephrosia spicata, the Spiked Hoarypea, is a small, native perennial that is found in scattered communities throughout North Carolina. In the Falls Lake area, it is usually found in open areas along roadsides and power lines, in ditches, and in open fields. It matures in the heat of the summer and blooms June through August, seemingly immune to high temperatures and drought. The compound leaves of T. spicata can be hard to see when in thick vegetation, so the summer pink or red blooms draw attention to the plant. In the photo below, the pink flower is in the center, surrounded by its compound leaves, indicated by small, yellow arrows.
The small plant below is growing in the open dirt at the edge of a roadway, allowing a better look at the sparse leaves and the sprawling growth habit. A flowering spike can be seen forming at one of the leaf axils. It is indicated by a red pointer. The long, thin flowering stalk is the origin of the “Spiked” part of the common name. In older references, the plant was once called “Spike-flowered Tephrosia”.
The leaves are covered by coarse brown, rusty hairs, and the tips of the leaflets end in a sharp point. The coarse, rusty hairs explain the “hoary” part of the common name.
Below are photos of the flowers as they typically appear. Although red flowers usually predominate, most have white flowers as well. The flowers tend to be closed most of the time, but sometimes open in the morning after a hard rain at night. They usually open in the mid to late afternoon, but they rarely open completely.
In the side view of this flower, the long, green, stalked structure extending from the flower is the style. The stamens can also be seen – smaller, white, and above the style.
The picture of the white flower below shows the green style protruding up from the flower, with the white stamens below it, mostly to the left. The stigma can be seen at the tip of the style. Note that even the style is covered with tiny hairs.
Tephrosia spicata is a member of the pea family, the Fabaceae. After the bloom, a typical legume or pod is formed. In the next two photos, the individual seeds can be seen forming along the top of the pod.
When not in flower, Tephrosia spicata can be confused with vetch (Vicia sp.), which also has compound leaves and similar habitat. The easiest way to differentiate the two in the field is to examine the terminal part of the leaf. The leaf of T. spicata terminates in a leaflet not a tendril; the plant drapes across foliage but does not climb. See below.
The leaf of a vetch terminates in a tendril that helps support the plant and allows it to climb.