356 



THE GARDENER'S ASSISTANT. 



Cypripedium. — The hardy species are mostly natives 

 of North America. One, C. Calceolus, is a rare British 

 plant. C. spectabile is the best of the genus, its large 

 pink-and-white pouch-like flowers being very lovely, and 

 freely produced. Their chief requirements are a moist 

 situation and shade. If cultivated in pans a covering of 

 moss should be given to prevent too much evaporation, 

 and the soil should be of peat and loam, and kept moist 

 always. 



C. acaule. Rose, 6 inches. North America. 



C. Calceolus. Brown and yellow, 1 foot. Europe (Britain). 



C. candidum. White, 6 inches. North America. 



C. macranthon. Deep-purple, 9 inches. Siberia. 



C. pibe <cenx. Purple and yellow, 9 inches. North America. 



C. spectabile. White and rose-pink, 1£ foot. North America. 



Dahlia. — This important genus is dealt with specially 

 elsewhere. The several species, if not so showy as their 

 garden progeny, are bright and pretty, and deserve to be 

 included in good collections. They require the same treat- 

 ment as the garden varieties ; they may be propagated 

 from seeds. 



D. coccinea. Scarlet, 4 feet. Mexico. 

 D. Merckii. Mauve, 3 feet. Mexico. 



D. variabilis. B-ose-purple, 4 feet. Mexico. 



Delphinium. — The many beautiful species, varieties, 

 and hybrids of this genus in cultivation are invaluable as 



Fig. 431.— Delphinium nudicaule. 



garden plants. Their colours range from white to all 

 shades of blue and purple and red. They are easy of 



cultivation in ordinary garden soil, although they well 

 repay rich treatment. The improved garden forms are 



Fig. 432.— Dianthus neglectus. 



dealt with specially elsewhere. Propagation can be 

 effected by root division, which should be done in spring 

 or summer. Good varieties and hybrids should be in- 

 creased in this way, or by cuttings and seeds. 



L. cardinale. Bright-scarlet, 2 to 3 feet. California. 

 D. cashmirianum. Pale-blue, 18 inches. Himalaya. 

 D. grandijlorum. Deep rich blue, 1 to 1J foot. Siberia. 

 D, nudicaule (fig. 431). Bright-red, 1J foot. California. 

 D. Zalil. Sulphur-yellow, 4 feet. Afghanistan. 



Dianthus. — A charming genus, which, besides contri- 

 buting the Carnation, Pink, and Sweet William, with 

 their numerous forms, contains some species of high 

 garden value. They are essentially plants for sunny 

 positions in the rock garden, provided there is moisture 

 enough at the roots. Their flowers generally possess 

 the charm of fragrance as well as beauty, and their 

 foliage, of glaucous hue, and evergreen, is another good 

 point. Several of the most beautiful, such as D. glacialis, 

 are difficult to cultivate, and are therefore omitted here. 

 Propagation by seeds, division, and cuttings. 



D, alpinus. Deep-rose, 4 inches. Europe 

 D. barbatvs. Pink and red shades, 



D. ccesius (Cheddar Pink). Rose, 6 inches. Europe (Britain). 

 D. callizonus. Rich rose, 2 inches. Transylvania. 

 D. chinensis. Rose, 3 feet. China. 



D. neglectus (fig. 432). Rose, with darker spots, 3 inches. 

 Europe. 

 D. petrceus. White, 6 inches. Eastern Europe. 

 D. plumarius. Pink, 6 inches. Europe (Britain). 

 D. superbus. Rose, 1 foot. Europe. 



Di centra. — Elegant plants with pretty fern-like foli- 

 age, and gracefully drooping racemes of heart or lyre- 

 shaped flowers. The best known is Z>. {Dielytra) specta- 

 bilis, "Solomon's Tears", which has pink and white 

 flowers, and besides being suitable for the border and 



