64 CRUCIFERiE. Thlaspi. 



Tribe VI. THLASPIDEJE. DC. 



Silicle dehiscent, compressed contrary to the very narrow septum; valves boat-shaped. 

 Cotyledons plane, accumbent, contrary to the septum. 



12. THLASPI. Dill. ; Endl. gen. ^885. penny cress. 



[From the Greek, thlao to flatten ; probably from the compressed form of it* seed-vessel.] 



Silicle emarginate at the apex ; valves vringed on the back ; cells 2- or many-seeded. Petals 

 equal. Calyx equal at the base. — Flowers white. 



1. Thlaspi arvense, Linn. Mithridate Mustard, or Penny Cress. 



Leaves oblong, toothed ; silicles orbicular-obovate, shorter than the pedicels ; style scarce- 

 ly any.— Pursh, fl, 2. p. 435 ; DC. prodr. 1. p. 175 ; Hook.Jl. Bor.-Am. 1. p. 58 ; Torr. 

 ^ Gr.fl.N.Am. 1. p. 113. 



Cauline leaves somewhat sagittate ; auricles minute. Valves of the sihcle much com- 

 pressed, furnished with a conspicuous wing. 



In the State of New- York {Fursh). I have never seen specimens of this plant collected 

 within the limits of the State. It is doubtless an introduced species in North America. 



Tribe VII. LEPIDINE^. DC. 



Silicle usually dehiscent, compressed contrary to the narrow septum {sometimes l-celled) ; 

 valves boat-shaped, or rarely ventricose. Cotyledons plane, incumbent, parallel to the 

 septum. 



13. LEPIDIUM. R. Br. in hort. Kew. 4. p. 85 ; Endl. gen. 4932. PEPPER-WORT. 



[From the Greek Upis, a scale; the fruit being in the form of little scales.] 



Silicle ovate or somewhat cordate ; valves carinate or rarely ventricose, dehiscent ; cells one- 

 seeded. Seeds compressed, or somewhat 3-sided. Flowers small, white. 



1. Lepidium campestre, R. Br. Mithridate Pepper-wort. 



Silicles ovate, winged, emarginate, scaly-punctate ; cauline leaves sagittate, denticulate. — 

 DC. syst. 2. p. 535 ; Torr. <^ Gr.jl. N. Am. \.p. 115. Thlaspi campestre, Linn. 



Annual or biennial. Plant 8-12 inches high, simple, or paniculately branched above, 

 clothed with a short soft and mostly simple pubescence. Racemes much elongated in fhiit; 

 pedicels diverging horizontally. Silicles 3 lines long. 



Waste places and road-sides ; rather rare. Long Island and Staten Island. Introduced. 

 June - July. 



