880 THLASPI. [CLASS XV. ORDER 1. 



arrow-shaped lobes at the base, embracing the stem, unequally waved 

 or toothed. Inflorescence terminal many flowered paniculated racemes. 

 Flowers small, white. Calyx of four ovate equal pale segments, with 

 a narrow white membranous margin. Petals white, ovate, small, with 

 a slender claw. Fruit an ovate siliqua, on a round slender hairy 

 pedicle, swollen on the lower side, somewhat cupped above, the keel 

 winged, the apex notched. ^Slyle slender, much longer than the lobes 

 of the notch, two celled, each cell containing a single pendulous dark 

 brown ovate seed, the valves smooth, or sometimes rather rough, with a 

 few depressed scales at the back. 



Habitat. — Cultivated fields and under hedges. Norfolk, Suffolk, 

 Nottinghamshire, Lincolnshire, frequent; common in Caernarvonshire 

 and Anglesea, and not uncommon in Scotland and Ireland. 



Perennial ; flowering in June. 



This, though having the general appearance of the last species, is 

 readily distinguished by its smooth fruit, and the slender style being 

 much longer than the lobes of the notch. Jt, like all the other species 

 of this genus, possesses warm stimulating properties ; the L. sativum 

 is well known as the common garden cress, which in a young state 

 with fSinapisJ mustard forms one of our earliest and most whole- 

 some spring salads. By cultivation, several varieties are obtained, as 

 the curled and broad leaved ; the former is an elegant plant for the 

 table ; the latter is chiefly used for feeding turkies. 



GENUS VI. THLAS'PL— Linn. Penny-cress. 



Nat, Ord. Crucif'eu^. Juss. 



Gen. Char. Silicula laterally compressed, the apex notched, of two 

 or many seeded cells, valves keeled or winged at the- back. Calyx 

 equal at the base. Petals equal. Filaments simple. Cotyledons 

 accumbent. — (c Fig. 1, page 871. — Name from 6xaw, flattened or 

 compressed ; so called on account of the shape of the seeds. 

 1. T. arven'se, Linn. (Fig. 1015.) Mithridate Mustard or Penny- 

 cress. Leaves oblong, smooth, toothed, those of the stem sessile, 

 arrow-shaped at the base ; silicula large, flat, with a broad winged 

 keel ; seeds numerous, circular, striated. 



English Botany, t. 1659.— English Flora, vol. iii p. 171.— Hooker, 

 British Flora, ed. 4. vol. i. p. 246. — Lindley, Synopsis, p. 27. 



Root small, tapering. Stem erect, about a foot high, branched 

 above, leaf}-^, smooth, a glaucous green. Leaves smooth, unequally 

 toothed on the margin, the radical ones obovate, obtuse, the upper 

 oblong lanceolate, arrow-shaped at the base, sessile, and embracing the 

 stem. Inflorescence terminal and lateral elongated many flowered 

 racemes, smooth. Calyx equal, ovate, concave, pale green. Corolla 



