CRUCIFER^E 71 



species of Arabis are. In August, 1911, the writer found A. alpina 

 growing as high as 10,500 feet on the north ridge of the Diablons 

 in Valais. 



Arabis arenosa Scop. 



Biennial. Stems 6-12 inches high, slender, branched, hairy like 

 the whole plant. Root-leaves lyrate - pinnatifid ; upper leaves 

 few, dentate or entire. Flowers pale pink or lilac or rarely white. 

 Sepals gibbous. Siliquas spreading, slender, forming a loose, 

 spreading raceme. 



Sandy places among rocks, local. Rare in Switzerland ; got at 

 Engelberg in 1910. April to July. 



Distribution. Northern and Central Switzerland, Central Jura, 

 Vosges, Central France, Bulgaria. 



A few Swiss specimens with pale lilac flowers have developed 

 pure white blossoms in a West of England garden. 



Arabis stricta Huds. (A. scabra All.) Bristol Rock-cress. 



Stem 310 inches, erect, simple, covered with hispid hairs like 

 the leaves. Leaves leathery, shining, dark green and occasionally 

 purplish, ciliated, wavy, with a few rounded teeth ; radical leaves 

 in a dense rosette ; cauline leaves 1-3, sessile, not auricled. Flowers 

 a dirty white. Sepals as long as the pedicels. Fruiting-spike short, 

 with widely erect pedicels. Siliqua erect, compressed. Seeds 

 truncate and slightly winged at the summit. 



Rocks, cliffs, and debris on limestone in the lower Alps and plains. 

 May to July. 



Distribution. East and South of France, Switzerland (Common 

 on the Saleve near Geneve), Jura, Pyrenees, Spain. On carbon- 

 iferous limestone rocks and screes near Bristol on both sides of the 

 Avon. 



Arabis bellidifolia Jacq. 



A glabrous and shining plant, or sometimes sparsely covered 

 with simple hairs. Stem 6-20 inches high, erect, simple, leafy. 

 Leaves thick ; the root-leaves oblong-spathulate, slightly wavy ; 

 the stem-leaves oval or oblong, entire or toothed, half-embracing 

 the stem. Flowers white. Side sepals 'swollen at the base, shorter 

 than the pedicel. Anthers oblong. Fruiting-spike elongated, with 

 erect pedicels. Siliquas long, numerous, erect, much compressed, 

 seeds broadly winged. 



Springs and damp pastures in the high mountains, commonest 

 at about 5000-6000 feet. June to August. 



Distribution. Carpathians, Eastern, Central, and Western Alps ; 

 Pyrenees, Norway. 



