166 THE FLORA. 



S. pinnatif^ida. A prostrate, weed-like plant, common at the South, in fields and ii\ 

 river-banks. Leaves divided in a pinnate manner, into oblong, toothed lobes. 

 Flowers obscure, with scarcely any petals. Silicles flattened, notched at apex, 

 wrinkled on the surface. Feb. -July, 



6. DRA'BA. V/hitlow- grass. 



Calyx equal at base. Petals equal. Filaments without teeth. Siliclo 

 oval-oblong, entire, flattened parallel to the broad partition. Cells 2, 

 many-seeded. Seeds not margined. — Low herbs, with small white or 

 yellow flowers in racemes. (See Fig. 396.) 



§ Petals 2-cleft, white. Leaves all radical 1 



I Petals entire or merely notched. Stems more or less leafy. . . .a 



a Style present. Plants perennial 2,3 



a Style none. Plants annual or biennial b 



b Pedicels as long or longer than the pod. . . .4, 5 



b Pedicels shorter than their pods 



1 D.verna. Spring W. Leaves oblong, hairy. Scape 1-5'' high. Q (See Fig. 396.) 



2 D. arabi'sans. Rock W. Leaves minutely toothed. Silicle twisted, longer than 



the pedicel, oblong-lanceolate, 4-6'''' long. Lake shores. (Figs. 155-159.) 



3 D. ramosis'sima. Bushy W. Leaves with remote and slender teeth. Silicle as 



long as its pedicel, style half as long. Flowers white. Kocks. 

 4 D. nemora'lis. Wood W. Petals notched at end. Pod half as long as iis 



pedicel. Seeds near 30. Flowers yellowish-white. N-W. 

 4 D. brachycar'pa. Short-fruited, W. Petals entire. Pod as long as pedicel, 



10-12-seeded. Leaves round-ovate. S. W. March, April. 



5 D. Carolinia'na. Leaves round-ovate, entire. Pods linear, in a £ort of corymb. 



Flowers white. Plant hispid, 1-3' high. E. S. April-June. 



6 D. cuneifo'lia. Wedge-leaved W. Leaves wedge-oblong. Pods lance-oblong, 20- 



30-seeded, racemed. Plant 3-S' high. S-W. 



7. AR'ABIS. Rock Cress. Sickle-pod. 



Sepals erect. Petals clawed, entire. Silique linear, flattened, valves 

 one-veined in the middle. Seeds in a single row in each cell. Flowers 

 white. April-June. 



§ Leaves all (or at least the radical) pinnatifid. . . .1, 2 

 § Leaves all undivided ; toothed or entire, often clasping.... a 

 a Siliques short (6-12'''') and straight. Seeds not winged. . . .3, 4 

 a Siliques longer (1-2''), straight or curved. Seeds not winged. . . .5, 6 

 a Siliques long (3''), curved, hanging. Seeds winged 7, 8 



