170 TETRADYNAMIA— SILICULOSA. Thlaspi. 



roundish, compressed ; cotyledons, according to DeCan- 

 doUe, accumbent, nearly orbicular. 

 Annual herbs, of humble growth, with numerous, pinnati- 

 fid, radical leaves, and several simple stalks, of which the 

 central one only is quite leafless. FL small, white, in 

 simple corymbose tufts, becoming long clusters oi pouches. 



1. T. ?mdicaulis. Naked-stalked, or Irregular, Tees- 



dalia. 



Petals unequal. 



T. nudicaulis. Br. in Ait. H. Kew. v. 4. 83. Comp.ed. 4. 1 10. Tr. 



of Linn. Soc. ?j. 1 1 . 286. Hook. Scot. 1 94. 

 T. Iberis. DeCand. Syst. v. 2. 392. 



Iberis nudicaulis. Linn. Sp. PI. 907 . Pf'ilkl. v. 3. 458. Fl. Br. 692. 

 , Engl. Bat. v. 5. i. 327. Curt. Lond.fasc. 6. t. 42. Dicks. H. Sice. 

 /asc. 1.10. Fl. Dan. t. 323. 

 I. n.52I. Hall. Hist. v.\. 224. 

 Nasturtium petraeum. Uaii Syn. 303. 

 Bursa pastoria minima. Ger. Em.276.f. Lob. Ic.22l.f. 

 Shepherd's Cress. Petiv. H. Brit. t. 50./. 2, 



In dry barren gravelly fields. 



About London, Norwich and Bury. Ray, and Engl. Bot. InWcr- 

 cestershire and Cumberland. Withering. Near Sheffield. Mr. 

 J. Salt. In cornfields near Easingwold, Yorkshire. Rev. Arch- 

 deacon Peirson. In several parts of the lowlands of Scotland. 

 Hooker. Abundant in Anglesea. Rev. H. Davies. 



Annual. May. 



Root slender, tapering. Leaves numerous, spreading on the 

 ground, partly undivided, but mostly pinnatifid in a lyrate man- 

 ner, often downy at the edges, otherwise smooth. Stems se- 

 veral, slightly leafy, erect or spreading, the central one quite 

 straight and always naked. Fl. in little white corymbs. Two 

 outer petals thrice the size of the others. Stam. always 6, re- 

 markable for their large white scales, first observed in this spe- 

 cies by the late Mr. Sowerby. 



TeesdaUa is named after the late Mr. Robert Teesdale, F.L.S., 

 formerly gardener to the Earl of Carlisle at Castle Howard, an 

 excellent British botanist, who died atTurnham Green, Dec. 25, 

 1804. T. regularis, the only species known besides, is Lepi- 

 dium nudicaule of Linnaeus, exactly like our plant in habit, but 

 distinguished by having equal petals, and often only 4 stamens. 



324. THLASPI. Shepherd's Purse. MIthridate 

 Mustard. 



Linn. Gen. 334. Juss. 24 1 . Fl. Br. 683. DeCand. Syst. v. 2. 373. 

 Tonrn.t.]Ol,F—L. DiU.Gen.t.6. Lam. t. 557. Gartn.t.l4]. 



