GOS 



XXIX. LYTHRACEAE 



The second of these plots is shown in Fig. 230. These figures show a veiy 

 rapid rate of growth and a high yield. Trees measured in 1915 in a plantation 

 in the Jalpaiguri district had attained a height of 18 ft. in five years. 



The rate of growth as deduced from measurements in two unthinned 

 sample plots in the Darjeeling division was as follows : ^ 



Duabanga sonneraiioides : girth increment in unthinned sample plots, 



Darjeeling division. 



The growth here is considerably slower than that shown in the first state- 

 ment : this is possibly due to the fact that no thinnings were carried out. 



Ring-countings in respect of 25 trees in the Tista valley gave an average 

 of 3-1 rings per inch of radius, rej)resenting a mean annual girth increment 

 of 2026 in. - 



Gamble's specimens averaged 5 rings per inch of radius (mean annual 

 girth increment 1-26 in.), while one specimen showed 2 rings per inch (mean 

 annual girth increment 3*14 in.). 



3. SONNERATIA, Linn. f. 



This genus comprises trees with opposite entire thick leaves, growing in 

 the mangrove swamps of littoral regions (see under ' Rhizophoraceae '). There 

 are four Indian species, of which two, S. acida, Linn, f., and S. apetala, Ham., 

 are fairly widelj^ distributed along the coasts and two, S. alba, Smith, and 

 S. Griffithii, Kurz, are far more local. 



Species 1. aS'. apetala, Ham.; 2. S. acida, Linn. f. ; 

 4. S. alba, Smith. 



1. Sonneratia apetala, Ham. Vern. Keora, Beng. 

 lanki, Tel. ; Marama, Tam. ; Kanbala, Burm. 



A small to moderate-sized evergreen tree with slender drooping branches 

 and light glaucous-green foliage. Bark black, smooth, with horizontal oval 

 lenticels. The tree produces thin upright rather sharp pneumatophores from 

 its superficial roots. It coppices vigorously. Wood moderately hard, used 

 for planking, furniture, knees of boats, and fuel. 



Distribution and habitat. Tidal forests of the coasts of India and 

 Burma. This is one of the chief constituents of the mangrove formation, 

 growing gregariously and springing up in more or less pure patches, usually 

 on new alluvial land thrown up in the form of islands or of flats in tlie bends 

 of tidal rivers and estuaries. It is a common tree in the Sundarbans, appearing 

 on newly formed land and gradually dying out on the higher ground, where 

 it tends to be replaced by Heritiera Fomes and other species. 



Flowering and fruiting. The Avhitish flowers appear from April to 

 June. Ripe fruits have been received from tlie Sundarbans in September. 



^ Statistics compiled in the Silviculturist's Office, 1916-17, Ind. For. Rec, vol. vi, pt. v. 

 - Working Plan for the Darjeeling Forests, J. W. A. Grieve, 1912. 



3. *S'. Griffithii, Kurz ; 

 ; Kandal, Mar. ; Ky- 



