324 



ROCK GARDENS 



PoLEMONiuM (Polemoniaceae), Jacob's Ladder 



Only the dwarfer species of this genus are suitable for the rock 

 garden. 



P. confertum. — Requires a warm position in well-drained, deep, 

 loamy soil. It has slender and deeply cut leaves, and clusters of 

 clear blue flowers, borne on stems about 6 inches high. Of easy 

 culture, but dislikes disturbance. Can be raised from seed, 

 mellitujn is a white form. 



P. ^«?;/z7^.— Requires a dry, light soil. Forms tufts of pale green 

 leaves and bears numerous pale blue flowers on stems a few inches 

 high. Blooms in June. Hardy in a well-drained position, but a 

 damp subsoil will prove fatal. Propagated by seed or division. 



P. reptans. — Is of creeping habit, and has loose panicles of slaty- 

 blue flowers, borne 6 or 8 inches high. Propagated by division or 

 seed. Slugs are very partial to this plant. 



PoLYGALA (Polygalaceae), Milkwort 



Interesting little plants, and some most suitable for the rock 

 garden. 



P. Chafnaebuxus. — Likes a half-shady position in sandy peat and 

 loam, well drained. It is evergreen, and forms compact tufts. 

 Flowers cream-coloured, and borne in profusion. The variety 

 purpu7'ea is better, having purple flowers with a yellow centre. Of 

 easy culture, and increased by division. Both are most attractive 

 plants. 



P. Rhodoptera and P. Vayredae are of the same type, with 

 crimson flowers. They are both of recent introduction. 



P. calcarea. — Very similar to the common Milkwort of our hills, 

 and is also a native. It will grow easily in calcareous soil, and is 

 a pretty little plant. 



PoLYGONATUM (Liliaceae), Solomon's Seal 



Attractive plants for growing amongst shrubs or on the higher 

 parts of the rock garden, where their graceful arching stems will 

 show to advantage. All are of easy culture in any light, well- 

 drained soil in partial shade, and are readily increased by division. 

 They are all deciduous. 



P. biflorum. — Grows i to 3 feet high, with arching stems, and 

 small greenish-white flowers in pairs. 



P. japonicum. — Grows about 2 feet high, and has white flowers 

 tinged with purple. 



P. latifoliu77i. — Bright green leaves on arching stems 2 to 3 feet 



