CRUCIFER.E. 103 



27. SISYMBRIUM. Flowers usually small, and mostly yellow or yellowish. Sepals oblong 

 to linear, usually spreading in anthesis, equalling or exceeding the claws of the obovate or 

 spatulate petals. Stamens 6, free, unappendaged. Style short or none ; stigma simple 

 or slightly bifid. Pods linear, short or long, nearly terete. Leaves from entire to bipiu- 

 uatifid or multifid. Pubescence hirsute with simple hairs, or stellate, or glandular, or none. 

 6. Septum nerveless or nearly so ; its cells smaller, thicker-walled, elongated transversely : 



boreal and arctic plauts with hairs branched, and leaves (in American species) entire 

 or merely dentate. 



28. BRAY A. Calyx, corolla, and audrcecium of ^((^/-rmrt. Style present but short ; stigma 

 more or less distinctly 2-lobed. Fruit oblong to linear-oblong ; valves flattish or convex, 

 faintly 1 -nerved, not keeled. 



•H- ++ Capsule strongly obcompressed, at least the upper part, or anomalous and 4-valved ! 



29. TROPIDOCARPUM. Sepals ovate-oblong, spreading. Petals obovate, cuneate. 

 Stamens 6, free and uuappeudaged. Style slender, sometimes short ; stigma circular and 

 entire or slightly emarginate. Silique partially or completely 2-celled, with a very narrow 

 partition, or 1 -celled. Seeds 2-4-seriate. Pubescence chiefly simple, a few branched hairs 

 being mixed with the others. 



-t— -t— Stigma (anomalous in tribe) bifid with short lobes over the valves. 



30. GREGGIA. Sepals oblong, spreading. Petals obovate, entire, cuneate. Stamens 6, 

 free, unappendaged; anthers olilong, cordate at base. Stigma somewhat ovate or conical; 

 the stigmatic surface elongated above the valves of the capsule not over the placentas. 

 Style slender. Seeds nearly uniseriate. Pubescence densely stellate. 



-!—•)—-(— Stigma subconical, with short lobes erect and approximate or connate. 



31. HESPERIS. Flowers showy, mostly purplish. Sepals erect, oblong; the lateral 

 saccate at base. Petals with loug and slender exserted claws and broad obovate or nearly 

 orbicular blades. Stamens 6, free and unappendaged. Pods very loug, spreading, torulose, 

 beaked ; valves 3-nerved. Leaves mostly undivided. Pubescence in part branched. 



* * Cauline hairs bifid and closely appressed. 



32. ERYSIMUM. Sepals oblong to linear-oblong, erect, equal at the base or the lateral 

 somewhat saccate. Petals commonly large, with broad obovate blades and slender elongated 

 claws. Stamens 6, free and unappendaged. Pods strongly compressed, broadly linear with 

 flat 1-nerved valves, or narrow and quadrangular with convex and more or less distinctly 

 keeled valves. Seeds numerous, oblong and turgid or suborbicular and flattened or winged. 

 Cotyledons incumbent or accumbent or the radicle not infrequently very oblique. 



Tribe VIII. ARABIDEJi]. Stigma when lobed prolonged over the placentae. 

 Fruit 2-celled, sometimes incompletely so, regularly dehiscent, short or long, 

 flattened parallel to a broad partition, terete or prismatic. Cotyledons accumbent 

 (in some species of Leavenworthia the embryo straight or nearly so). Pubescence 

 simple, branched, or absent. 



* Pods globose, terete, or prismatic, at least not compressed parallel to the partition, 

 •t— Flowers (in North American species) white : pods subglobose to short-oblong, often 

 somewhat obcompressed : leaves entire, augulate, or shallowly toothed, not pinnatifid. 



33. COCHLEARIA. Sepals short and broad, rounded at apex. Petals obovate, cuneate, 

 or very shortly unguiculate. Stamens straight, free. Style slender, sometimes very short ; 

 stigma simple or nearly so. Capsule (in North American species) very turgid ; valves dis- 

 tinctly 1-nerved. Seeds 2-several, biseriate in the cells. 



-f— -I— Flowers yellow, rarely white • pods short-oblong to linear : some or all of the leaves 

 usually pinnatifid. 



34. NASTURTIUM. Flowers small. Sepals ovate to elliptic-oblong, spreading in 

 anthesis, often colored. Petals obovate or spatulate, cuneiform at base ; scarcely clawed 

 sometimes minute or wanting. Pods terete or nearly so; valves thin, nearly or quite nerve- 



