100 CRUCIFER.E. 



3. THYSANOCARPUS. Flowers small. Sepals ovate, rounded, spreading. Petals spat- 

 ulate. Stamens as in the last. Style slender, short or rarely absent ; stigma simple. 

 Ovule solitary. Fruit winged. Pubescence simple or none. 



* * * Fruit orbicular or nearly so, 2-celled, dehiscent, 2-several-seeded : filaments often 

 dilated and toothed or appeudaged near the base. 



4. BERTEROA. Sepals oblong, rounded at the apex. Petals obovate, bifid, cuueate 

 below. Stamens 6 ; filaments somewhat appeudaged upon the inner surface near the base. 

 Stvle slender, rather long. Stigma essentially simple. Pods flat, often tomentose. Seeds 

 several in each cell, winged or margined. Pubescence stellate, not appressed. 



5. LOBULARIA. Sepals short, ovate, spreading in anthesis. Petals obovate, cuneate, 

 entire. Stamens 6 ; filaments slender, rarely dilated below, not toothed. Silicel small ; 

 valves flat or slightly convex. Style slender ; stigma subsimple. Cells few-seeded. Hairs 

 2-parted and appressed. 



6. ALYSSUM. Sepals short, ovate or oblong, more or less spreading. Petals obovate, 

 cuneate to spatulate or linear, entire or slightly retuse at the summit. Stamens 6 ; fila- 

 ments commonly more or less dilated at the base and toothed. Capsule with valves convex. 

 Pubescence densely stellate. 



Tribe II. PHYSARIEiE. Fruit a silicel, 2-cell8d, completely dehiscent, either very 

 turgid with broad partition and almost hemispherical valves, or didymous, or 

 strongly obcompressed with narrow partition and conduplicate. Cotyledons 

 accumbent. Pubescence stellate. 



# Silicel subglobose ; partition broad, suborbicular. 



7. LESQUERELLA. Sepals oldong or elliptical, rather short, equal at base, erect or 

 spreading, usually pubescent. Petals longer, spatulate to oblong-obovate, entire. Stamens 

 6; anthers linear, sagittate; filaments rarely dilated or winged at the base. Style slender; 

 stigma entire or nearly so. Pods mostly very turgid; cells 2-16-seeded; septum uerved 

 from the top to the middle. Seeds rarely margined. 



* * Silicel didymous or obcompressed ; partition narrow, elliptical, oblong or linear. 



-1— Seeds several to many. 



8. PHYSARIA. Floral envelopes and andrcecium of the preceding. Style slender. Fruit 

 more or less strongly didymous and inflated or sometimes rather strongly obcompressed, but 

 the cells at least somewhat turgid at maturity. 



9. SYNTHLIPSIS. Sepals oblong, spreading in anthesis. Petals longer ; blade flat, obo- 

 vate ; claw rather short. Stamens 6, unappendaged. Style slender ; stigma simple. 

 Capsule elliptic-oblong, very strongly obcompressed ; valves sharply carinate, not auriculate 

 or wing-appendaged. Seeds about 10 iu each cell, neither margined nor winged. 



10. LYROCARPA. Sepals linear or linear-oblong, acute or acutish, erect, equal at base. 

 Petals long, linear to obovate, sometimes twisted. Stamens six, free, unappendaged. Style 

 short or none ; stigma rather large, entire or somewhat lobed ; the lobes lying over the 

 valves. Capsule very strongly obcompressed, oblong and biauriculate at the apex, or short, 

 broad and obeordate. Septum narrow, linear. 



-i— H— Seeds solitary in each cell. 



11. DITHYREA. Sepals ovate or oblong, erect or spreading, pubescent. Petals conspicu- 

 ous, broadly spatulate, with spreading blades and slender claws. Stamens 6, free and 

 unappendaged ; anthers linear, sagittate. Pods very strongly obcompressed and didymous ; 

 cells suborbicular ; septum very narrow and shorter than the cells. Style almost none ; 

 stigma rather large, somewhat ovate, simple. 



Tribe III. LEPIDINEiE. Fruit a 2-celled silicel, strongly obcompressed (except in 

 the aquatic genus Subularia). Cotyledons incumbent or accumbent. Pubescence 

 wholly simple or none. 



* Fruit strongly obcompressed, dehiscent ; cells 2-several-seeded ; cotyledons accumbent : 

 terrestrial and glabrous. 



