172 TETRADYNAMIA-SILICULOSA. Thlaspi. 



2. T. perfoliatum. Perfoliate Shepherd's Purse. 



Pouch inversely heart-shaped. Stem-leaves heart-shaped, 

 rather sharp at the base, clasping the branched stem. 

 Style very short. 



T. perfoliatum. Linn. Sp. PL 902. JVilld. v. 3. 446. Fl. Br. 685. 

 Engl Bot. V. 33. t. 2354. Hook. Land. t. 46. DeCand. Syst. 

 v.2.378. Jacq.Austr.t.337. 



T. alpestre. Huds. 282. Dicks. H. Sicc.fasc. 6. 5. 



T. arvense perfoliatum minus. Raii Sijn. ed. 2. J 76. 



T. arvense perfoliatum majus. Bauh. Pin. 106. Moris, v. 2. 294. 

 sect. 3. t. \7.f. 15 i also minus. f.]6. 



T. perfoliatum minus. Bauh. Pin. 1 06. Raii Syn. ed. 3. 305. 



T. alterum mitius rotundifolium. Bursas pastoris fructu. Column. 

 Ecphr.v. J. 278. t. 276./. 2. 



T. cordatum minus, flore albo, insipidum. Barrel. Ic. ^ 815. 



T. tertium pumilum. Clus. Hist. v. 2. 131./. 



T. minus Clusii. Ger. Em. 268./ 



T. rotundifolium. Ger. Em. 266./ good. 



Nasturtium n. 5 10. Hall. Hist. v. 1 . 220. 



Small Thorow Cress. Petiv. H. Brit. t. 50. f. 12. 



In limestone pastures, rare. 



Abundant among the stone-pits about Burford, Oxfordshire. Bo- 

 bart and Sibth. I believe it has not been found In any other 

 part^ of Britain. The north-country stations introduced into 

 Ray's Synopsis by Dillenius, certainly belong to T. alpestre. 



Annual. April, May. 



Root fibrous. Herb glaucous, smooth. Stem branched from the 

 very bottom, spreading, leafy. Leaves slightly toothed ; radical 

 ones stalked, ovate, obtuse ; the rest sessile, arrow-shaped, 

 clasping the stem, either rounded or acute at the base. Fl. 

 densely corymbose, small, white. Cal. often purplish, with white 

 membranous edges. Pouches on horizontal stalks, in not very 

 long clusters, the keels of their valves much dilated and rounded 

 at the upper part, rising high above the very short style. Seeds 

 numerous in each cell, oval, yellowish. 



Morison's/ ] 6, and T. tertium pumilum of Clusius, copied in Ger. 

 Em. clearly belong to this, as they faithfully express the short- 

 ness of the style. I have starved specimens very nearly answer- 

 mg to those figures. The great Ray was aware that authors had 

 here made two species out of one. 



3. T. alpestre. Alpine Shepherd's Purse. 



Stem-leaves arrow-shaped. Stems simple. Style promi- 

 nent beyond the margin of the obovate abrupt pouch. 



T. alpestre. Linn. Sp. PL 903. M'illd.v.3.447. FLBr.OSG. EngL 

 Bot. v.2.t.S\. DeCand. Syst. v. 2. 380. 



