500 XXVI. RHIZOPHORACEAE 



years, and the minimum felling limit being a girth of 1 ft. at 4| ft. from ground- 

 level. The system is said to be difficult to control, and when, as sometimes 

 happens, the crop consists mainly of stems 1 ft. in girth and over, clearings 

 may result, and artificial reproduction has to be resorted to.^ The retention 

 of seed-bearers in such places should help to regenerate the blanks naturally. 



Artificial reproduction. Artificial reproduction is a simple matte/;, 

 the embryos being collected off the ground after falling and stuck vertically 

 in the mud. In the Andamans mangrove plantations were commenced in 

 1897, the species employed being Rhizophora mucronata, R. conjugafa, Bruguiera 

 gymnorhiza, B. parvifiora, Kandelia Rheedii, and Ceriops Candolleana. These 

 plantations were extended until 1908, when the total area amounted to 685 

 acres, the cost of creation being Rs. 5,368 or slightly under Rs. 8 per acre. 

 The original spacing is said to have been 3 ft. by 3 ft., which proved to be 

 excessively close, and some years later alternate rows were cut out, as well as 

 alternate saplings in each row, leaving a spacing of 6 ft. by 6 ft. These planta- 

 tions have suffered much from the erection of bunds already referred to, whereby 

 the flow of fresh and tidal water was interfered with. 



In Burma in 1908 five acres in the Zapathwe fuel reserve in the Hantha- 

 waddy district were cleared of all undergrowth and species of little value and 

 planted 4 ft. by 4 ft. at the end of October with Rhizophora mucronata (2 acres), 

 R. conjugata (1 acre), and Kandelia Rheedii (2 acres). The overhead clearance 

 caused early drying of the mud, while hog-deer ate off the main shoots, with 

 the result that only about 30 per cent, of the seedlings survived until the 

 following May, and these were in poor condition. Similar experiments with 

 Rhizophora mucronata and R. conjugatu in the Mingalun fuel reserve in the 

 same district gave better results, about 30 per cent, of the former species and 

 40 per cent, of the latter being in good condition, with a height of about 

 2| ft., by the following May. In the Federated Malay States the embryos 

 are usually dibbled in 4 ft. by 4 ft. or 6 ft. by 4 ft., and the percentage of sur- 

 vivals is high, almost the only danger being from crabs, wliich eat through 

 the stem at its base. 



Rate of growth and out-turn. The rate of growth of mangroves is 

 said to be slow, but actual statistics are not available except in the case of 

 the Andamans plantations, where Rhizophora mucronata and Bruguiera gym- 

 norhiza attained a height of 30-35 ft. and a girth of 9-12 in. in fifteen years. 

 Sample plots in Arakan gave an average yield per acre of 3 tons of bark and 

 25 tons of wood in clear-felled coupes. 



Genera 1. Rhizophora, Linn. ; 2. Ceriops, Am.; 3. Kandelia, W. and 

 A. ; 4. Bruguiera, Lam. ; 5. Carallia, Roxb. 



L RHIZOPHORA, Linn. 



Species 1. R. mucronata. Lam. ; 2. R. conjugata,, Linn. 



1. Rhizophora mucronata, Lam. Vern. Bfutra, Beng. ; Randal, Mar. ; 

 Kamo, Sind ; Uppu pottm, Tel. ; Pyu, Burm. 



A small to moderate-sized evergreen tree with elliptical mucronate leaves 

 4-7 in. long, the young branches thick and prominently marked with the scars 

 of fallen leaves and stipules. Bark fairly smooth, brown. This tree produces 

 1 The Mangrove Forests of the West Coast, F.M.S., J. P. Mead, 1912. 



