132 TETRADYNAMIA SILICULOSA. [CI. 15. 



*** Cotyledons folded, incumbent. 



342. BRaSSICA. Pod nearly cylindrical, beaked, with 2 valves. 



Seeds nearly globular. Calyx closed. 



343. SINAPIS. Pod nearly cylindrical, somewhat beaked, with 2 



valves. Seeds nearly globular. Calyx spreading. 



344. RaPHANUS. Pod tumid, imperfectly jointed, without valves. 



Seeds globular. 



TETRADYNAMIA SILICULOSA. 



316. VeLLA. Cress-rocket. 



1. V. annua, 21. 1442. (Annual C.) Leaves doubly pinnatifid. Pouches 

 deflexed. 

 Sandy fields, rare ; not native. © . 6. Stem erect, rough. Pet. yell. 



317. SUBULaRIA. Awlwort. 



1. S. aqudtica, 11. 732. (Water A.) 



Alpine lakes, under water. 0.7. L. awl-shaped. Fl. white. 



318. DRABA. Whitlow-grass. 



1. D. verna, 9. 586. (Coaimon W.) Stalks radical, naked. Petals 



deeply cloven. Leaves lanceolate, somewhat notched, hairy. 

 Walls, banks, &c. 0.3,4. Hairs some simple, someforhed. Fl. white. 



2. D. aizoides, 18.1271. (Yellow W.) Stalks solitary, naked. Petals 



slightly notched, twice the length of the calyx. Leaves lanceo- 

 late, rigid, keeled, fringed. 

 Walls and rocks, near Swansea. 11. 3. Tufted. Fl. few, yellow, 

 corymbose. 



3. D. hirta, 19.1338. (Simple-haired W.) Stalk nearly leafless. Pe- 



tals undivided. Pouch elliptic-oblong. Leaves lanceolate, slightly 

 toothed, fringed with simple hairs. — D. rupesli'is, Br. 

 Ben Lawers. If.. 5,6. Fl. small, white. Pet. with a shallow notch. 



4. D. incdna, 6. 388. (Hoary W.) Stem-leaves numerous, hoary, like 



the stem, with close starry pubescence. Pouch elliptic-oblong, 

 oblique, or twisted, longer than the hairy partial stalks. 

 Alpine rocks. £ . 5,6. Hoary. Fl. numerous, white. Pet. obcord. 



5. D. murdlis, 13. 912. (Speedwell-leaved W.) Stem branched. 



Leaves heart-shaped, toothed, hairy. Pouch elliptical, obtuse, 

 flat, shorter than the partial stalks. 

 Shady mt. pi. . 5. Fl. numerous, sjnall, white. Pet. obov. entire. 



319. ALYSSUM. Alyssum. 



1. A. maritimum, 25. 1729. (Sweet A.) Stem somewhat woody, much 

 branched, spreading. Leaves lanceolate, acute, entire, hoary with 

 close hairs. Stamens simple. 



