i oo Encyclopaedia of Gardening 



suitable for the rockery (see Flower Garden). D. caryophyllus is 

 the Carnation, D. plumarius the garden Pink, D. barbatus the 

 Sweet William, and D. chinensis the Indian Pink. The following 

 are the best Alpines ; all thrive in sandy loam in crevices : alpinus, 

 red, June (Botanical Magazine, t. 1205), top-dress annually with 

 fresh soil; caesius, the Cheddar Pink, pale pink, July, enjoys lime- 

 stone chips; cruentus, scarlet, July; deltoides, the Maiden Pink, 

 pink, June; glacialis, red, June, likes a sunny aspect and a gritty soil 

 containing leaf mould; neglectus, rose, June; and superbus, white, 

 summer (Bot. Mag., t. 297). Atkinsoni, May, 9 ins., crimson, is 

 brilliant, and likes shade. 



Diascea (dia-scea, from diaskeo, to adorn, in reference to the 

 beauty. Ord. Scrophularineae) . One species is esteemed, both 

 for greenhouse and flower-garden Culture, and that is Barberae, a 

 half-hardy annual with rosy flowers in early summer, growing about 

 a foot high (see the Botanical Magazine, t. 5933). For culture, see 

 Annuals. 



Dibber. Dibble. A short pointed wooden tool useful for planting 

 greens. 



Dicentra (dicen-tra, from dis, twice, and kentron, spur, in reference 

 to the form. Ord. Fumariaceae) . The old and popular name is 

 Dielytra. Spectabilis, with its beautiful pink pendent flowers, is 

 much the most popular, and is good both for herbaceous borders 

 and pots (see Bulbs). Eximia and formosa are also worth growing 

 in the herbaceous border. The former is illustrated in the Botanical 

 Register, t. 50; and the latter in the Botanical Magazine, t. 1335. 



Dicksonia (dickso-nia, after Mr. J. Dickson. Ord. Filices). A 

 genus of handsome ferns, some of which are classed with the tree 

 ferns. They thrive in a compost of 2 parts loam, i leaf mould, and 

 .a liberal dash of sand. Propagation is by spores (see Ferns). Like 

 most ferns, they enjoy abundance of water. Antarctica is the 

 principal species. 



Dictamnus, Dittany (dictam-nus, Virgil's name. Ord. Rutaceae). 

 The species Fraxinella, the Burning Bush or Bastard Dittany, is 

 interesting on account of the stems being covered with resin, which 

 burns if touched with a lighted match at night. It is a hardy herba- 

 ceous plant, bearing its white flowers in late spring. It conforms 

 to the general treatment of its class, but does not lend itself to 

 division, and may therefore be propagated by seed. The purple is 

 .a variety, although the two are often grown in the reverse way, i.e., 

 the purple as the species. Giganteus (caucasicus) is a large form. 



Dieffenbachia (dieffenbach-ia, after Dr. Dieffenbach. Ord. 

 Aroideae). Handsome foliage plants, suitable for warm houses. A 

 compost of loam, with a third of peat and leaf mould, and some sand, 

 suits them. They have a distinct growing season, during which 

 they must have abundance of moisture, both at the root and in the 

 atmosphere; less water will be needed when they go to rest in 

 autumn. They should be shaded from hot sunshine. Cuttings of 

 young shoots will strike in heat in spring, and so will pieces of stem. 

 Three of the principal species are Chelsoni, Imperator, and picta. 



