CRUCIFER^E. 25 



Section I. SILICULOSiE. Pod short and broad. 

 1. TIILASPI. Linn. Penny Cress. 



Gr. thlao; to compress or flatten: on account of the flattened silicles. 



Calyx equal at the base. Petals equal. Silicle short, 

 flat, emarginate at the apex, many-seeded j valves, bract-form, 

 winged on the back; cells 2, many seeded. Cotyledons 

 accumbent. — Annual herbs with undivided leaves and whits 

 or p urplish flo wers. 



1. T. aryense, L. Penny Cress. 



Leaves oblong-sagitate, coarsely toothed, smooth; silicle (pouch) roundi?h-ob- 

 ovate, shorter than the pedicel, its wings dilated longitudinally: stigma subsessile. 



Cultivated stony field?. June. Stem a foot high, erect, and somen hat branched. 

 Leaves 1 to 2 inches long, % as wide. FU/wers small, white in terminal racemes. 

 The plant has a disagreeable flayer of garlic. 



2. T. tuberosum, Nutt. Tuberous Penny Cress. 



Leaves rhomboid-ovate, obscurely dentate, smooth and sessile : radical ones 

 petiolate ; silicle suborbicular. April and May. Stem i to 5 inches high. Flowers 

 rather large, rose-colored. 



2. CAPSELLA. DC Shepherd's Purse. 



Diminutive of capsa, a chest or box : in allusion to the fruit. 



Calyx equal at base. Silicles triangular, wedge-form, 

 obcordate, compressed laterally ; valves carinate, not winged 

 on the back. Style short. Seeds many. Annual. Flowers 

 white. 



C. Bursa-pastoris, DC. Shepherd's Purse. 



Radical leaves pinnatifid, hairy; cauline ones oblong, more or less toothed, 

 sagitate at base. 



Cultivated grounds. April — Oct. A troublesome weed. Stem 6 to 12 inches 

 high. Flowers small) in racemes, which are finally 3 to 12 inches long. Intru- 

 duced from Europe. 



3. ERIOPHILA. DC 



Gr. er, eros, spring; KOAphileo, to love : in allusion to its early flowering. 



Calyx equals Petals 2-parted. Stamens without teeth. 

 Silicle oval or oblong; valves flat. Seeds many, not mar- 

 gined. — Annual. Flowers small. 



E. VULGARIS, DC. Whitlow Grass. 



Leaves oblong-lanceolate, acute subscrrate, hairy : scape naked : petals bifid ; 

 stigma sessile: silicle flat, oval, shorter tban the pedicel. 



Fields. March — May. Scape 2 to 6 inches high. Flowers minute, whit«. Pouch 

 on long pedicels. 



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