222 ROCK GARDENS 



A. Pyrenaica. — It bears rich yellow flowers on all the branches 

 of its slender stems in April. 



A. walziana. — This is a hybrid : A. vernalis and A. volgensis. 

 It requires same treatment and position as the last named. It bears 

 narrow-petalled, yellow flowers in April that expand very fully. 

 The stems, which are stiffly erect, and about 12 inches high, are 

 clothed with finely cut pale green foliage. 



^THIONEMA (CrUCIFERAE) 



A charming family of dwarf-growing rock plants, forming rather 

 untidy little bushes, with leaves mostly of a glaucous blue colour. 

 The flowers are borne in crowded terminal racemes. All the 

 species can be cultivated on the warmer slopes of the rock garden, 

 and increased by seed or cuttings in the summer. They are all 

 deep-rooted, and dislike disturbance or damp soil. 



AL. armenum. — Warm, sunny position, requiring a deep root-run 

 of a light, dry, stony nature. It does well in hmestone. It is of 

 dwarf habit, growing only 3 or 4 inches high, with dense spikes 

 of small, purplish-rose-coloured flowers. Dislikes damp, and is 

 liable to perish in a wet winter. 



^. capitatum. — Same position and soil as the last. Numerous 

 thick stems, growing only a few inches high, with somewhat acute 

 linear leaves rather scattered. Small and inconspicuous flowers. 

 It is chiefly remarkable for its dense heads of boat-shaped seed- 

 vessels with entire wings. 



^. cepeaefolium (syn. Hiitchinsia rotiindifolid). — Requires 

 a deep, dry root-run in a sunny position. Densely tufted 

 stems, rising 3 to 6 inches, with glaucous, green, fleshy leaves f 

 to I inch long, those from the root obovate, those on the 

 stem sessile. Flowers pale lilac, with a yellow eye, half an inch 

 across, in cylindrical, crowded, erect racemes. A pretty and 

 attractive plant. 



^. cordatum. — Sunny position ; deep root-run. A shrubby 

 little plant, growing 9 inches high, with rather large sulphur-yellow 

 flowers in dense heads in August. Propagated by cuttings or seed. 

 A good rock plant for a dry bank. 



jE. cordifolium. — Sunny position and dry, deep root-run 

 required. A compact, shrubby little plant, growing only about 6 

 inches high. Short, crowded leaves, and rather large, rosy-pink 

 flowers in clusters. Blooms in June and July. Hardy in dry 

 situation, and propagated by seed or cuttings. A handsome 

 species. 



yE. grandifiorujn. — Demands same position and soil. Forms 

 quite a little bush about 12 inches high, with rather long slender 



