ON TREES AND SHRUBS, 



455 



are : vioiacea, with deep violet-coloured flowers ; those of flore-albo 

 are white ; azurea^ deep blue ; the leaves of foliis-argenteis are 

 beautifully striped and mottled with silver ; while those of foliis- 

 aureis are marked with yellow. The Vincas are readily propagated 

 by division and by cuttings. 



Yucca. — This is a very orna- 

 mental group of Liiiace(E, com- 

 prising about a score of species, 

 tender and hardy, but not more 

 than nine or ten can be con- 

 sidered suitable for culture 

 out of doors in this latitude. 

 Yuccas are amongst the most 

 graceful of all hardy plants, 

 and delight in a fairly rich, 

 moist, and well-drained soil. 

 Those here mentioned are 

 perfectly hardy, and produce 

 charming effects planted either 

 singly or in groups on the lawn. 

 They are also well adapted for 

 planting on or near the rockery, 

 on sloping mounds, and look 

 well in the centre of beds, 

 with dwarf shrubs or suitable 

 bedding plants grouped round 

 them. Tliey have few equals for 

 winter bedding, 

 and for filling 

 vases for decora- 

 tion during winter. 

 Y. recurvi- 

 folia (Fig. 

 287) can be 

 well recom- 

 mended. Y. 

 gloriosa 

 (Adam's 

 Needle) 

 is a well- 

 known species, 

 having been intro- 

 duced from North 

 America upwards 

 of 300 years ago. 



It is of a vigorous growth, with flat and sharply-pointed leaves, 

 and on warm soils throws up its great flower-spikes in July and 

 August. The pendent bell-shaped flowers are white, tinged with 



Fig. 287. — Yucca recurvifolia. 



