RHODOTYPOS ROMNEYA. 311 



and R. maximum, are probably best. R. Ponticum is ex- 

 tensively used in Europe, but it is not hardy enough for the 

 north, unless worked low and planted deep. See Azalea. 



Rhodotypos. Seeds ; or like Kerria. 



Rhubarb. See Rheum. 



Rhus (Sumach). Anacardiacece. 



Seeds, layers, suckers, root cuttings, and cuttings of 

 green or ripe wood. Suckers are oftenest used. 



Rhynchospermum. See Trachelospermum. 

 Ribes (Currant, Gooseberry). Sojcifragactiz. 



Seeds, which should be sown as soon as ripe, or else 

 stratified for new varieties. Commonly from ripe cut- 

 tings. See Currant and Gooseberry. 



Richardia (Calla). Aroidece. 



Offsets, which should be removed and potted off when 

 the plants are at rest. Old crowns may be divided. 



Ricinus (Castor Bean). Euphorbiacece . 



Seeds, which in the north are started indoors. 



Rivina (Hoop Withy). Phytolaccacecz. 



Readily propagated by seeds ; also by cuttings, inserted 

 during spring in heat. 



Robinia (Locust, Rose Acacia). Leguminostf. 



Seeds, sown in fall or spring, and which usually germi- 

 nate better if soaked in hot water previous to sowing. 

 Also grown from layers and root cuttings. Named varie- 

 ties are grafted or budded, the common locust stock 

 ( R. Pseudacacia) being preferred, even for the rose acacia 

 (R. hispida}. 



Rocambole (Allium Scorodoprasum). Liliacetf. 



"Cloves," or division of the bulb. 

 Rocket, ornamental sorts. See Hesperis. 

 Rocket Salad (Eruca sativa). Crucifercz. 



Seeds, sown where the plants are to grow. 

 Rock-Rose. See Cistus. 

 Romneya. Papaverace&. 



Propagated by seeds in spring. 



