CRUCIFERAE. 457 



few, in 2 rows in each cell of the pod, orbicular, flat, broadly winged, free from the 

 septum* Cotyledons accumbent. [Greek, moon, from the resemblance of this 

 genus to Lunaria. ] Two or three species, natives of the south-central United States 

 and northern Mexico. 



I. Selenia aurea Nutt. Selenia. (I. F. f. 1741-) Stems simple, numer- 

 ous, 0.5-2 dm. high. Basal leaves 2-5 cm. long, narrow, 1-2 pinnatifid into numer- 

 ous oblong dentate segments ; stem-leaves similar, smaller ; bracts of the raceme 

 pinnatifid, resembling the upper leaves; flowers 6-8 mm. high, numerous; pedicels 

 1-1.5 cm. long in fruit, spreading or ascending; pod 1-2 cm. long, 4-6 cm. broad; 

 style 4 mm. long, very slender. In open places, Mo. and Kans. to Tex. March- 

 April. 



23. LEAVENWORTHIA Torr. 



Low annual glabrous scapose herbs, with lyrate-pinnatifid persistent basal 

 leaves, and few or solitary terminal flowers. Petals wedge-shaped. Siliques flat, 

 broadly linear or oblong, short-stipitate, dehiscent ; valves nerveless, finely retic- 

 ulate-veined. Seeds in I row in each cell of the pod, flat, winged or margined; 

 radicle short, slightly bent toward the cotyledons. [In honor of Dr. M. C. Leaven- 

 worth, U. S. A.] A genus of about 4 species, natives of southeastern North Am. 



Pods not constricted between the seeds. 1. L. uniflora. 



Pods constricted between the seeds. 2. L. tornlosa. 



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

 (I. F. f. 1742.) Tufted, 7-15 cm. high. Basal leaves rosulate, 2-10 cm. long, the 

 segments 5-17, dentate or angled, 4-6 mm. long, the terminal one somewhat larger, 

 all narrowed near the base; stem-leaves none, or 1-3, smaller; flowers about 6 mm. 

 broad; petals white or purplish with a yellow base, about twice the length of the 

 sepals ; pods oblong or linear, 1-3 cm. long, 4 mm. wide when mature ; seeds 

 winged; style about 1 mm. long. In open, dry places, S. Ind. to Tenn. and Mo. 

 April. L. Michauxii Torr.] 



2. Leavenworthia torulosa A. Gray. Necklace Leavenworthia. (I. F. 

 f. 1743.) Closely resembles the preceding, but the pods are narrower and con- 

 stricted between the seeds. Style 3-4 mm. long ; seeds sharp-margined, barely 

 winged ; terminal segment of the basal leaves decidedly broader than the lateral 

 ones. Barrens of Ky. and Tenn. April. 



24. PHYSARIA A. Gray. (See Appendix.) 



Low perennial stellate-canescent herbs, with usually simple stems, spatulate 

 mostly entire leaves, the basal ones tufted, and yellow flowers in terminal racemes. 

 Petals longer than the sepals. Style filiform. Silicles membranous, stellate pubes- 

 cent, their cavities inflated, subglobose, the septum narrow. Seeds not margined; 

 cotyledons accumbent. [Greek, bellows, from the resemblance of the inflated fruit.] 

 About 4 species, natives of western N. Am. 



1. Physaria didymocarpa (Hook.) A. Gray. Double Bladder-pod. (I. F. 

 f. 1744.) Root long and deep. Stems slender, 0.7-3 dm. long; leaves spatula te, 

 the basal ones obtuse, entire, or few-lobed, narrowed into margined petioles; blade, 

 or terminal segment, 2-13 cm. long; stem-leaves nearly sessile, acute or subacute, 

 much smaller; flowers I— 1. 3 cm. broad; pods didymous, variable, often I cm. thick 

 through the strongly inflated cavities, emarginate at base and summit, commonly 

 broader than high; seeds numerous. In dry soil, N. W. Terr, to Br. Col., Neb., 

 Colo, and Nev. May-Aug. 



25. LESQUERELLA S. Wats. # 



Low herbs, with stellate pubescence, simple leaves, and racemose mainly yellow 

 flowers. Petals entire. Anthers sagittate. Pod generally inflated, globo c e or 

 oblong; valves nerveless; septum translucent, nerved from the apex to the middle. 

 Seeds several or many in each cell of the pod, flattened, marginless or narrow- 

 margined: cotyledons accumbent. [Dedicated to Leo Lesquereux, 1805 1889, 

 Swiss and American botanist.] About 35 species, natives of America, and mainly 

 of the western parts of the U. S. 



