Flower:

Blossoms are single in the upper leaf axils, only a few opening at a time in ascending progression up the stem. The yellow flowers are 1/3 to ¾ inch across with 4 round petals, notched at the tip, and several veins radiating from the base. 8 yellow stamens surround a 4-parted style in the center. The green to reddish calyx tube behind the flower resembles a stalk and is about as long as the ovary nestled in the leaf axil. The raceme-like cluster nods to one side, becoming erect where each flower blooms. The leaf-like bracts at the base of each flower are narrower and more sharply tapered at the tips than leaves lower on the stem. Flowers open during the day and close at night.

Leaves and stems:

Leaves are 1 to 2¼ inches long and up to ¾ inch wide, generally lance-elliptic, toothless, blunt at the tip, tapered to a narrow base, and stalkless. Both surfaces are covered with short appressed hairs. Stems are green to reddish, variously covered in very short hairs, usually erect and unbranched or with some branching on mature plants.

Fruit:

Fruit is an upright, club shaped capsule up to ½ inch long with four prominent, reddish, length-wise ridges and covered in short, glandular hairs.

Notes:

Small Sundrops is easy to identify from the nodding tip of the stem and club-shaped fruit. While it can be found on drier sites, it is a decidedly eastern species requiring adequate annual moisture to persist. It is rarely encountered in great numbers, typically a scattered plant here or there within its habitat. While not as showy as the more garden popular Southern Sundrops (Oenothera fruticosa), there is little reason it shouldn't persist well in a backyard native garden.