RHODODENDRON 349 



selection and hybridisation to the most valuable group of evergreen garden 

 rhododendrons in existence the group which flowers at the end of May and 

 in June. The characteristics of this group, as compared with the companion 

 group derived from R. ponticum, are their broad foliage and greater hardiness. 

 The rhododendrons known in gardens as EVERESTIANUM and FASTUOSUM, 

 the former with a frilled corolla, the latter double-flowered, are forms of 

 catawbiense. 



R. CAUCASICUM, Pallas. * 



An evergreen, low shrub, usually under 2 ft. in height, with slightly downy 

 young shoots. Leaves sometimes rather leathery, smooth and dark green 

 above, more or less clothed with brownish red felt beneath ; narrowly oval or 

 slightly obovate ; 2 to 4 ins. long, f to i^ ins. wide ; stalk stout, \ in. long. 

 Flowers yellowish white or with a pale lilac tinge, produced during June in 

 terminal clusters. Corolla 2 ins. across ; stamens ten ; calyx very small ; 

 flower-stalk slightly downy, about i- ins. long. 



Native ofjthe Caucasus ; introduced in 1803. Although its hybrid progeny 

 is numerous in gardens, the true species is itself nd'w scarcely ever seen. It 

 is an interesting dwarf bush, remarkable for its dense habit and slow growth. 

 As it approaches 8000 ft. altitude in a wild state it is very hardy. Nearly 

 allied to it is 



R. CHRYSANTHUM, Pallas, found in Siberia and N.E. Asia. It has yellow 

 flowers and differs in its smaller leaves, quite smooth on both surfaces. 

 Although closely allied botanically to R. caucasicum it is very unsatisfactory 

 under cultivation, so much so, that from my experience with it I should say 

 it was. not worth growing. I have never seen it in flower. 



Many of the garden varieties of Rhododendron with a blotch of yellow on 

 the otherwise white corolla are derived in part from R. caucasicum. Amongst 

 the more notable hybrids are the following : 



CAUCASICUM PICTUM. A compact bush up to 6 ft. high, with thinner 

 branches and freer habit than caucasicum. Flowers soft, pale rose, spotted 

 on the upper side, opening in early May or even late April. 



CUNNINGHAM'S WHITE. Raised by James Cunningham of Comely Bank 

 nurseries, Edinburgh, about 1830, from R. caucasicum crossed with ponticum 

 album. According to information received from Mr James Smith of the 

 Darley Dale nurseries, this variety thrives well in a limestone district, in 

 evidence of which are a large number of thriving plants planted by his firm 

 near Buxton. A robust shrub 10 ft. high, flowers white. 



NOBLEANUM (g.v.\ caucasicum x arboreum. 



PULCHERRIMUM (see under Nobleanum). 



ROSA MUNDL Very near caucasicum in leaf and habit, being a dwarf 

 rounded bush, only 2 or 3 ft. high in twenty years ; flowers white with a slight 

 flush and a yellow spot. 



STRAMINEUM (Bot. Mag., t. 3422). A shrub, 5 or 6 ft. high, with the foliage 

 of caucasicum, and pale yellow or straw-coloured flowers. 



SULPHUREUM. Raised at^ Comely Bank nurseries from caucasicum and 

 arboreum album. Flowers of a pretty sulphur yellow, produced in April and 

 May. One of the best yellow hardy rhododendrons. 



VENUSTUM. A hybrid between caucasicum and R. arboreum, raised by 

 Mr W. Smith, of Norbiton, near Kingston. It flowers in April, and is a beautiful 

 variety, the corolla pale in the centre, deeply suffused towards the margin with 

 rose and blotched with dark purple on the upper side. It is of spreading 

 habit, and grows 4 to 6 ft. high. A very similar plant (R. JACKSONI), said to 

 come from caucasicum crossed with Nobleanum, was raised by Mr Jackson, 

 also of Kingston. 



The caucasicum group of rhododendrons is distinguished by the cluster of 



