CRUCIFEU^E. 103 



27. SISYMBRIUM. Flowers u.siuilly small, anil iiio.'<tly yellow or yellowwh. SojialH oMoug 

 to linear, usually s))ri'adiufi; iu anthesis, etiualliiij^ or exit'Ciliii;^ the dawn of the olKjvate or 

 spatulate jietals. Stamens 6, free, unappendaged. Style sliort or none ; Htigma cimjilo 

 or slightly bifid. I'ods linear, short or lon}^, m-arly terete. Leaves fmni entire to hipin- 

 natifid or multitid. Pubescence hirsute with simple hairs, or «t<llate, or f^landular, or none 

 h. Septum nerveless or nearly so; its cells smaller, thicker-walled, elongated transven««-l\ 



horeal and arctic plants with hairs branched, and leaves (in American speeieH) eniir«- 

 or merely dentate. 



28. BRAY A. Calyx, corolla, and andriecium of A'tir/cma. Style present but shi>rt; stij;ina 

 more or less distinctly 2-lobed. Fruit oblong to linear-oblong ; valv<'s Hattish or convex, 

 faintly 1-nerved, not keeled. 



++ ++ Capsule strongly obconipressed, at least the upper part, or anomalous and 4-valve«i ! 



29. TROPIDOCARPUM. Sepals ovate-oblong, spreading. I'etals obovaU', cuneate. 

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

 entire or slightly emarginate. Silique partially or completely 2-celle<l, with a very uarmw 

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

 being mixed with the others. 



-*- -(- Stigma (anomalous in tribe) bifid with short lolies over the valves. 



30. GREGGIA. Sepals oblong, spreading. I'etals obovate, entire, cuneate. Stamens 6, 

 free, unappendaged ; anthers oblong, cordate at base: Stigma somewhat ovate or conical ; 

 the stigniatic surface elongated above the valves of the capsule not over the placenta:. 

 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 ere<t, oblong; the lateral 

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

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

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



* * Cauline hairs bifid and closely appressed. 



32. ERYSIMUM. Sepals oldong 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, oblung and turgid or suborbicular and flattened or winged. 

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



Tribe VIIL ARABIDE^. Stigma when lobed prolonged over the placentne. 

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

 flattened parallel to a broad partition, terete or prismatic. Cotyledons aecuml>ent 

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

 simple, branched, or absent. 



* Pods globose, terete, or prismatic, at least not compresse<l parallel to the partition. 

 ^- Flowers (in North American species) white: pods subgloboso to short-oblong, often 

 .somewhat obconipressed : leaves entire, angulate, or shallowly toothed, not pinnatifid. 



33. COCHLEARIA. Sepals short and broad, ronnded at a])ex. Petals obovate. cuneate, 

 or very siiurtly unguiculate. Stamens straight, free. Style slender, aometinip.s very short : 

 stigma sinq)le or nearly so. Capsule (in North AmVrican sjiecies) very turgid ; valves dii»- 

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



^_ 4_ Flowers yellow, rarely white ■ pods short-oblong to linear : some or all of the leaves 

 usually pinnatifid. 



34. NASTURTIUM. Flowers small. Sepals ovate to elli|.tic-old<ing, gpreadJiiK in 

 anthesis. often colored. Petals obo.ate or spatulate, cuneiform at base; wnn-cly clawed. 

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



