MUSTARD FAMILY. 191 



Hillsides and valleys of the interior and of the inner Coast Ranges from 

 Colusa Co. to Livermore Valley and southward. A.pr. 



17. THYSANOCARPUS Hook. 

 Slender erect annuals with the stems commonly sparingly branched or often 

 simple, and minute white or purplish flowers. Sepals ovate, spreading. Petals 

 spatulate. Stamens 6, subequal, with slender filaments. Ovary 1-celled, 1- 

 ovuled. becoming an indehiscent fruit; this much flattened and winged, or- 

 bicular in outline, the body disk-shaped or plane on one side and convex on 

 the other, the wing with small holes or perforations or with radiating nerves 

 (rays) or toothed. (Greek thusanos, fringe, and karpos, fruit.) 



Fruiting pedicels more or iess recurved their whole length. 



Wing of the obovate fruit with radiating nerves, mostly without holes 



1. T. curvipes. 



Wing of the commonly roundish fruit perforated 2. T. elegans. 



Wing of fruit scarious, not perforated, the radiating nerves none or very short 



3. T. emarginatus. 



Fruiting pedicels straight or recurved only at the very tip; wing broad with conspicuous 



rays 4. T. radians. 



1. T. curvipes Hook. Frixge-pod. Slender, 1 to 1V 2 ft. high, more or 

 less pubescent or hirsute; cauline leaves linear or lanceolate, sessile and auricled 

 at base, the upper entire, the lower dentate or denticulate; radical leaves often 

 narrowed at base to a petiole, commonly sinuate-pinnatifid, with triangular 

 acute or acuminate lobes; fruit obovate varying to round-obovate, pubescent 

 or glabrous, 1% to 3 lines long, often very convex on one side; wing narrow, 

 rather crowded with broad rays; pedicels recurved. 



Frequent everywhere in the open hill country of California. Apr. -May. 



2. T. elegans F. & M. Lace-pod. Rather stout, with few branches; 

 lower leaves repand-toothed; fruit nearly orbicular, 3 to 4 lines long, the body 

 densely tomentose; wing with large ovoid perforations between the rays, the 

 margin membranaceous and entire. 



Middle Xorth Coast Ranges; Antioeh; Sierra Xevada foothills. 



3. T. emarginatus Greene. Freely branching from the base, 1% ft. high; 

 herbage ostensibly glabrous but the plant at the fruiting stage hispidulous under 

 a lens, at least on the lower parts; cauline leaves linear, lanceolate, sessile, not 

 auricled; flowers and radical leaves unknown; fruit 2 to 2% lines long, gla- 

 brous; the wing scarious, entire, destitute of radiating nerves or these very 

 short, sometimes deeply, always slightly emarginate at the apex. 



Mt. Diablo; Antioeh. Too near to and evidently passing into T. curvipes. 



4. T. radians Benth. Rarely branching, 1 to 1C. ft. high; radical leaves 

 runcinate-pinnatifid, the cauline ovate-lanceolate, auriculatc-clasping; fruit 

 orbicular, 4 lines broad, glabrous or tomentose, the edge of the body divided 

 into radiating spoke-like nerves which disappear abruptly just within the 

 margin of the white-membranaeeous wing; pedicels straight, abruptly recurved 

 at the very summit. 



Low hills or rolling plains, infrequent, but widely distributed in central Cali- 

 fornia-: Eealdsburg; Sonoma; Vacaville; Antioeh; Linden. Apr.-May. 



Alyssi'm makitimtm (L.) Lam. Sweet Alyssum. Low branching peren- 

 nial herb with narrowly lanceolate or linear leaves and white flowers l' lines 

 long; petals twice as long as the deciduous sepals; filaments not toothed; pod 



orbicular, 2-seeded. — An escape from the gardens. A. calycinum L. Small 



Alyssum. Annual with decumbent branches; petals yellowish white, scarcely 

 iing the sepals; sepals persistent about the base of the fruit; filaments 



