114 CRUCIFERAE. [Voi,. II. 



i. Thlaspi arvense I,. Field Penny-cress. (Fig. 1692.) 



Thlaspi arvense L,. Sp. PI. 646. 1753. 



Annual, erect, glabrous, 6'-i8' bigb, sim- 

 ple or branching above. Basal leaves 

 petioled, oblanceolate, early deciduous; 

 stem-leaves oblong or lanceolate, sparingly 

 dentate, the upper clasping the stem by an 

 auricled base, the lower merely sessile; 

 flowers white, about i" long, ^ // broad; 

 pedicels spreading or curved upward, slen- 

 der, *>"-<)" long in fruit; pods nearly orbicu- 

 lar when ripe, 4 // -6 // broad, very flat, 

 broadly winged all around, notched at the 

 apex, in long racemes; style minute, or 

 none; seeds rugose, about 6 in each cell. 



In waste places and on ballast, sparingly 

 adventive or fugitive from Europe in the East- 

 ern and Middle States, but abundant in Que- 

 bec and a bad weed in Manitoba and the 

 Northwest Territory. Native also of northern 

 Asia. June-Aug. Called also Bastard Cress. 



a. Thlaspi perfoliatum L,. Perfoli- 

 ate Penny-cress. (Fig. 1693.) 



Thlaspi perfoliatum L. Sp. PI. 646. 1753. 



Annual, glabrous, branched at the base, 

 stems commonly simple, slender, ascending 

 or erect, 3 X -7 X tall. Basal leaves ovate 

 or suborbicular, often petioled; stem-leaves 

 oblong or oblong-lanceolate, sessile, auricled 

 at the base and clasping the stem, #'-i' 

 long, $"-6" wide, obtuse or acute at the 

 apex; pedicels filiform, spreading; silicic ob- 

 ovate-orbicular, 2 // -3 // broad, rather nar- 

 rowly winged, broadly notched at the sum- 

 mit; style short but manifest; seeds usually 

 4 in each cell. 



Near Hamilton, Ontario. Fugitive or adven- 

 tive from Europe. May-Aug. 



7. COCHLEARIA L. Sp. PI. 647. 1753. 



Annual or perennial maritime herbs, with simple alternate mostly fleshy leaves, and 

 white or rarely purplish or yellowish racemose flowers. Silicic inflated, oblong or globose. 

 Valves very convex, dehiscent. Stigma nearly simple, or capitate. Seeds several in each 

 cell of the pod, usually in 2 rows, marginless. Cotyledons mainly accumbeut. [Greek, 

 spoon, from the shape of the leaves.] 



A genus of about 25 species, not well understood, all natives of the colder parts of the noith 

 temperate zone. Besides the following, about three others are found on the arctic and northern 

 Pacific coasts of North America. 



