904 ARABIS. [CLASS XV. ORDER 11. 



simple hairs, and sometimes they are scattered over the under side, 

 ovate or ovate oblong, the radical ones numerous, crowded, tapering 

 at the base into a short footstalk, often tinged, of a purplish hue, the 

 upper ones sessile, rounded at the base. Inflorescence a terminal sub- 

 corymbose raceme, becoming elongated. Pedicles slender. Calyx 

 ovate oblong, with a narrow membranous margin, smooth. Corolla 

 of four ovate erect or slightly spreading white petals, about as long 

 again as the calyx. Fruit an erect slender linear siliqua, with a pro- 

 minent dorsal rib and longitudinal veins, crowned by the obtuse 

 stigma. Seeds " linear, impressed with numerous dots." 



Habitat. — Gravelly beach near the sea, at Rynville, Cunnamare, 

 on the western point of Bear Island, County of Kerry ,'and on the shore 

 at Derrinane, Ireland ; rocks near Loch Lea, in Glen Esk, Scotland. 



Biennial ; flowering in July and August. 



4. A. hirsu'ta, Broivn. (Fig. 1044.) Hairy Rock-cress. Stem erect, 

 hairy below; leaves oblong, hispid, and toothed, the radical ones 

 tapering into a footstalk, the upper sessile, auriculated or cordate at 

 the base ; siliqua erect, linear, compressed, with a prominent dorsal 

 rib and longitudinal slender veins. 



English Flora, vol. iii. p. 213. — Hooker, British Flora, ed. 4. vol. 

 i. p. 252. — Lindley, Synopsis, p. 24. — Turritis hirsuta, Linn. — English 

 Botany, t. 587. 



Root long, tapering, branched. Stems mostly several, erect, simple, 

 or branched, about a foot high, round, clothed in the lower part with 

 spreading hairs, nearly smooth above. Leaves oblong, rough, with 

 forked hairs, the lower ones numerous, crowded, spreading, tapering 

 into a footstalk of greater or less length, more or less toothed or entire, 

 often purplish, those of the stem sessile, heart-shaped or auriculated at 

 the base, the auricles spreading, mostly more deeply toothed than the 

 lower leaves, /w^orescewce terminal sub-corymbose racemes, becoming 

 much elongated. Pedic/es slender, swollen at the top. Calyx smooth, 

 of four oblong pieces, with a narrow membranous margin. Stamens 

 with slender filaments and small ovate anthers. Stigma sessile, 

 obtuse. Fruit an erect linear compressed smooth siliqua, the valves 

 with a prominent dorsal rib and slender longitudinal veins. Seeds 

 small, brown, with membranous base. 



Habitat. — Walls, dry banks, or rocks; frequent in many parts of 

 England, Scotland, and Ireland. 



Biennial ; flowering in May and June. 



This is an extremely variable plant in the hairiness of the leaves and 

 stem, and the hairs are sometimes all simple, at others all forked, and 

 often both o.n the same plant. The leaves are someiimes quite entire, 

 at others slightly toothed, and often deeply toothed, almost pinnated ; 

 the lower leaves are sometimes spatulate, and the upper linear oblong. 

 These variations seem to depend upon the situation of its growth being 

 dry or moist,^and its greater or less exposure to the sun. 



