POLYPETALOUS EXOGENOUS PLANTS. 161 



naked peduncle; petals emarginate, much longer than the 

 calyx ; silides oblong-linear, minutely hairy, longer than 

 the horizontal pedicels. March, April. 



LEPIDIUM, L. Pepper Grass. 



Silich rounded or obcordate, compressed contrary to the 

 narrow partition ; valves carinate ; cells 1-seeded. Coty- 

 ledons accumbent and incumbent. Petals sometimes 

 wanting. Stamens 2, 4, or 6. Leaves entire, toothed, or 

 pinnately divided. Floivers minute. Very common. 

 March- June. l°-2° high. 



STREPTANTHUS. 



Silique very long, compressed or somewhat quadran- 

 gular. Style short or none. Seeds in a single series, flat, 

 marginal. Sejmls erect, colored. Claivs of the petals 

 canaliculate, usually twisted. Filaments subulate, those 

 of each pair of the longer stamens sometimes united; 

 anthers linear; annual or biennial, rarely perennial herbs, 

 with purple, rarely white or yellow flowei's. 



* Petals narrow, calyx closed. 



S. HTACINTHOIDES, Hook. Glabrous ; leaves oblong, 

 linear, acuminate, 2^6tals spatulate-linear, the limb re- 

 flexed ; filaments of the longer stamens united by pairs. 

 Near San Felipe de Austin. — Driimmond. 



** Limb of petals broad, calrjx slightly spreading. 



S. MACULATUS. Leaves ovate-oblong, broad, clasping, 

 entire, or minutely and remotely repand-denticulate ; petals 

 obovate, purple ; siliqnes somewhat four-sided. Stem l^°-2° 

 high, sometimes much taller, usually simple, sometimes 

 branched, glabrous, glaucous terete. Leaves 3-6' long, 

 1^' broad, glaucous, rather acute. Floivers in simple or 

 paniculate racemes, very showy. Petals deep purple, 



