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ORDER XXXIV. ERICACEAE 



This order is not of great importance in Indian forestry, though two 

 species, Rhododendron arboreum, Sm., and Pieris ovalifolia, T>. Don., are famihar 

 trees in the Himalaya and other hill regions, where they are useful in clothing 

 hill-sides and acting as nurses to more valuable species. All the Indian species 

 of this order, of which at least forty belong to the genus Rhododendron, are 

 trees or shrubs of the hills, many ascending to high elevations. 



Genera 1. Rhododendron, Linn. ; 2. Pieris, D. Don. 



1. RHODODENDRON, Linn. 



Rhododendron arboreum, Sm. Vern. Chahan, Haz. ; Chiu, burdns, 

 W. Him. ; Zalatni, Burm. 



A small evergreen tree, often with a somewhat crooked or gnarled trunk. 

 Bark soft, easily cut through with a pocket-knife, 0-5-1 in. thick, old bark 

 grey, exfoliating in irregular longitudinal plates, exposing the smooth pinkish 

 new bark beneath. The wood is of inferior quaUty, both as timber and as fuel. 



Distribution and habitat. This is a common tree in the western 

 Himalaya, occurring chiefly at 5,000-8,000 ft. in association with Quercus 

 incana and Pieris ovalifolia, and at the lower elevations with Pinus longifolia, 

 but ascending to 11,000 ft. or even higher. It is somewhat rare in Hazara, 

 being commonest in the Siran Pinus longifolia forests at 4,000 ft. and upwards 

 in moist ravines. It extends to the eastern Himalaya, where, however, it is 

 less common ; it is also found in the Khasi hills and the hills of Burma, 

 southern India, and Ceylon. 



Flowering and fruiting. The large showy crimson, sometimes pink, 

 flowers in dense corymbs appear usually from March to May, but in certain 

 years only partial flowering takes place then, and a second flowering takes 

 place in June or July ; this happened in the Simla hills in 1916, following 

 an exceptionally dry winter and spring, and the flowers of the second bloom 

 were paler in colour than usual. Similar late flowering is also said to take 

 place if the first bloom is checked by hail or other injury. Occasionally trees 

 may be seen in flower in January-February. The fertilization of the flowers 

 is carried out partly by insects. Mr. G. B. F. Muir notes an interesting case 

 observed in Tehri Garwhal of Indian martens {Martes flavigula) visiting one 

 cluster of flowers after another and thrusting their noses into the flowers to 

 lick up the nectar ; fertiHzation is thus carried out by their agency, and 

 possibly birds may also be agents in cross-fertilization. 



The capsules (Fig. 242, a) are 0-8-M in. long by 0-3-0-4 in. in diam.eter, 

 oblong, curved, greenish brown when ripening, then turning brown. They 

 contain a large number of minute dark brown compressed oblong seeds about 

 0-05 in. long, with a fimbriate tuft at either end (Fig. 242, 6). The capsules 

 open and shed their seeds chiefly from January to March (western Himalaya). 

 The open capsules as a rule remain many months on the tree. 



Germination (Fig. 242, c-e). Epigeous. The radicle emerges from one 

 end of the seed and descends. The hypocotyl elongates, arching slightly, and 



