THE NURSERY-LIST 409 



Retinospora, species of Chamsecyparis and Thuja (Japanese Arbor- 

 Vitse). Pmocece. 



The retinosporas do not constitute a distinct group of plants, but 

 are juvenile forms in other genera. They are grown sometimes from 

 seeds, which should be denuded of pulp. Layers of tender branches 

 are sometimes employed. Most commonly grown from cuttings. 

 These are made from tips of growing or ripened shoots, and are 2 or 

 3 inches long, with all the leaves left on. They are usually, from 

 necessity, variously branched. The soft cuttings are usually taken 

 from forced plants, and are handled in a close frame or under a bell- 

 glass, with bottom heat. In commercial establishments the cuttings 

 of ripe wood are preferred. Following is the practice of one of the 

 oldest nurseries in the country: Cuttings of the entire season's 

 growth, cut to a heel, are taken in October and November, and are 

 placed in sand in boxes in gentle heat, as in a propaga ting-house. By 

 February the roots will be formed, and the boxes are then placed 

 in a cool house where the temperature is about 50. Early in spring 

 (about April 1st) the boxes are placed outdoors in coldframes, where 

 they remain until May, until frost is over. The boxes are then 

 removed from the frames and are set on boards in a shady place, 

 where they are left until fall. In the fall having been nearly a 

 year in the boxes the plants are shaken out and are heeled-in in a 

 cellar. The next spring they are planted out in beds, and during the 

 following summer and winter they are given some protection from 

 sun and cold. Yews and arbor-vitses are handled in the same way. 

 Usually the retinosporas propagate easily from cuttings taken in 

 autumn if given shade ; good-sized pieces root in ordinary soil. 



Retinosporas are often grafted on retinospora or common arbor- 

 vitse stocks. This operation is usually performed on potted plants 

 in winter by the veneer method. 



Rhamnus (Buckthorn). Rhamnacece. 



The hardy kinds may be increased by means of seeds or by layers. 

 The greenhouse species may be multiplied by cuttings of growing 

 parts in summer. Seeds should be stratified or sown in fall. Rarer 

 kinds are sometimes grafted on related species, R. Frangula and R. 

 cathartica being mostly used as stocks. 



Rhapis. Palmacece. 



Propagated by suckers which are produced freely, or by imported 

 seeds. See Palms, page 377. 



