Low winter-annual glabrous scapose herbs, with lyrate-pinnatifid basal leaves, and few or solitary terminal flowers. Petals wedge-shaped. Siliques flat, broadly linear or oblong, short-stipitate; valves dehiscent, nerveless, finely reticulate-veined. Seeds in 1 row in each cell of the pod, flat, winged or margined; embryo straight, or nearly so, the redicle short, slightly bent toward the cotyledons. [In honor of Dr. M. C. Leavenworth, U. S. A.]

A genus of about 4 species, natives of southeastern North America. Type species: Leaven-worthia aurea Torr.

1. Leavenworthia Uniflòra (Michx.) Britton. Michaux's Leavenworthia

Fig. 2097

Cardamine uniflora Michx. Fl. Bor. Am. 2: 29. 1803. Leavenworthia Michauxii Torr. Ann. Lyc. N. Y. 4: 89.

L. uniflora Britton, Mem. Torr. Club 5: 171. 1894.

Tufted, 2'-6' high. Basal leaves rosulate, numerous, 1'-4' long, the segments 5-17, irregularly dentate or angled, 2"-3" long, the terminal one somewhat larger, all narrowed near the base, but slightly expanded at the junction with the rachis; stem-leaves none, or 1-3, similar, but smaller; flowers about 3" broad; petals white or purplish with a yellow base, about twice the length of the sepals; pods oblong or linear, 6"-15" long, 2" wide when mature; style stout, about i" long.

In open dry places, southern Indiana to Missouri and Tennessee, west to Missouri. April.

2. Leavenworthia Torulòsa A. Gray. Necklace Leavenworthia

Fig. 2098

Leavenworthia torulosa A. Gray, Bot. Gaz. 5: 26. 1880.

Closely resembles the preceding species, but the pods are narrower and distinctly constricted between the seeds. Style conspicuous, 1 1/2"-2" long; seeds sharp-margined, barely winged; terminal segment of the basal leaves decidedly broader and larger than the lateral ones; petals notched.

Barrens of Kentucky and Tennessee. April.