200 TEtRADYN. SIL1GI. 



Six to ten inches long, slender, with few leaves, and those mostly 

 radical. 



3. A. ciliata (alpine Tower 'Mustard) leaves subdentate oval 

 glabrous ciliated, radical ones nearly sessile obtuse, cauline 

 ones semiamplexicaul, stem simple. Br. E. B. t. 1746 

 (Turritts alpina}. 



HAB. Rocks near Loch Lea, in Glen Esk, G. Don. Fl. July. <? . 

 Four to six inches high. Radical leaves several, oval or obovato- 

 oblong, obtuse. Cauline ones small. Pods nearly erect. 



4. A. kirsula (hairy Tower -Mustard), leaves all hispid dentate, 

 cauline ones semiamplexicaul, pods straight. Br. Lightf. 

 p. 358, and E. B. t. 587 (Turritis hirsuta). 



HAB. Dry rocks, frequent ; as upon the rocks in the King's park, 

 Edinb., Lightf. Habbies How and Pentland hills, Maugh. Bot- 

 tom of Cartlane Crags, Glasg., plentiful, Hopk. Fl. June. < . 

 (V, Sm.) 



One foot or more high, very straight, stiff. Stem rough with spread- 

 ing hairs, with many leaves. Flowers small, white. Pods nearly 

 erect. 



5. A. Turriia (Tower Wall-Cress), leaves amplexicaul, pods 

 recurved flat and linear with the margins incrassated, brae- 

 teas foliaceous. E. B. t. 1/8. 



HAB. Old walls, very rare. Castle of Cliesh, Mr. Arnott. FL May. $ . 



One foot or more high. Leaves many upon the stem, oblong, toothed, 

 a little rough, with short pubescence, especially the lowermost, spa- 

 thulate ones large, but gradually smaller upwards, and the upper- 

 most ones become bracteas, each bearing in its axil a single flower- 

 stalk. Flowers small, yellowish white. Pods very long, bent 

 backward when ripe. 



13. TURRITIS. 



1. T. glabra (long-podded Tower -Mustard] radical leaves 

 dentate hairy, cauline ones amplexicaul entire glabrous. . 13. 



t.777. 



HAB. Dry pastures, rare. In the wood opposite the inn at Bowling- 

 Bay, sparingly, Hopk. Fl. May, June. . 



One to two feet high. Leaves oblongo-lanceolate, glaucous ; radical 

 ones toothed or sinuated at the base ; cauline ones sagittate. Flow- 

 ers yellowish white. Pods long, erect. Whole plant very erect, 

 and traight. 



14. BARB AREA. 



1. B. vulgaris (Miter Winter. Cr ess] ^ lower leaves lyrate the 

 terminal lobe rounded the superior ones obovate toothed. 

 Lightf. p. 355, and. J5. /. 443 (Erysimum Barlared), 



HAB. Banks of ditches and rivers, but not very common. By the side 

 of the water of Leith, Dr. Parsons. Very frequent in hedges and 

 waste ground, and banks of rivers, about Gilasg., Hopk. Fl. May, 

 Aug. if.- 



