154 GLENN y"s handbook 



ill sand in a gentle heat. /. tuhulosa, flowers violet purple, 

 ill July. 



lONOPSIDUM. Violet Ckess. [CruciferfE.] A pretty 

 dwarf hardj annual, forming a beautiful plant for rockwork 

 in a shady situation, or an under-growth for a peat border or 

 for pot culture. It forms close to the soil a compact tuft, 

 studded with numerous lilac cross-shaped flowers. /. acaule, 

 flowers lilac. 



IPOM^EA. [Convolvulaceae.] A large genus of showy 

 Convolvulus-like plants, consisting mostly of climbing species, 

 of which the greater number require a stove temperatm'e. 

 The sub-shrubby and perennial kinds are increased by cut- 

 tings of the short lateral shoots in sandy soil under glasses. 

 Those which have fleshy roots are more difficult to propagate, 

 unless cuttings of the young shoots whicli break from the 

 crown of the tuber are taken : they require brisk bottom 

 heat. The tuberous fleshy-rooted sorts may sometimes be 

 increased by division, but not readily. Portions of the roots, 

 however, of the commoner sorts serve as stocks, on which the 

 rarer and more difficult may be grafted with success by what 

 is called herbaceous grafting, a good heat and a close frame 

 being indispensable. The annuals are raised by seeds sown 

 in a hotbed only in spring. The soil for them should be 

 turfy peat and sandy loam, with plenty of gritty sand added, 

 and the roots well drained. The fleshy-rooted kinds require 

 to be kept moderately dry in winter. Their habit is various. 

 Some bloom in the axils along the branches ; and others, in- 

 cluding I. HorsfalUcB, which is one of the best, bloom only at 

 the end of the shoots. With these latter it is a practice to 

 top the shoots when five or six feet long, to cause several 

 laterals to branch out ; and the result is that, though the 

 blossoming is retarded, there are many more flowers pro- 

 duced in the end. Stopped in this way, and trained over the 

 roof or the wall of a stove, this is one of the finest of all 

 creepers. I. JicifoUa, stove tw'ining perennial, flowers rosy 

 purple, in August. I. HorsfallicD, stove twining shrub, 

 flowers crimson, in October. I. imndiirata, hardy twining 

 perennial, flowers white and purple. I. ruhroccBridea, half- 

 hardy twining annual, flowers blue, fading red. There are 

 numerous other varieties. 



