HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. 75 



interfered with, will flower and the clump will thus contain double the usual number 

 of flowering culms. A natural result of the presence of this unusual number of large old 

 culms is that less light is available for the healthy development of young culms of the 

 current season, of which therefore an unusually small number are produced. The natural 

 result is again an unusually small proportion of flowering culms the following year. 



As the commercial munj is only obtained from the upper leaf-sheaths of the flowering 

 culm, it would appear from the above that the areas worked for thatching grass and munj 

 should be kept distinct, in the former the grass should be cut over annually towards the 

 close of the season of vigorous growth and in the latter, damage to the leaves, by cutting or 

 otherwise, should be avoided as far as possible. 



The mode of growth and development of the culms in Erianthus Ravenna? is practi- 

 cally identical to that described above except that the basal scales are usually four in 

 number. In old clumps of Erianthus, however, it has been noticed that the culms which 

 originate from the buds of the rhizome frequently show an average of 20 short basal inter- 

 nodes measuring 2 — 4 inches and such culms apparently persist for three years, whereas 

 the axillary culms which originate at a higher level show the normal development. 



It is believed that such shoots commence their development at the break of the rains 

 in June, whereas the average shoot starts vigorous growth in February. This is possibly 

 on account of insufficient light being available, until the old dead leaves in the clump have 

 been beaten down by the rain and are more or less decayed. During the first season such 

 a shoot would be expected to show ten short internodes (four with scales and six with leaves 

 for the period June — November). During the second year, owing to the upper leaves reach- 

 ing a considerable height in the clump, activity might commence in February and an addi- 

 tional 10 short internodes might result for the period February — November. The flower- 

 ing culms eventually produced in the third season from these long persistent bases usually 

 show unusual vigour both as regards diameter, length and number of long internodes. It 

 is believed that similar development occurs in S. Munja. 



54. The remarks given under this head for SusceptMi- 



itv to Fire 



S. Narenga below apply also to this species as regards the kind of damage done by fire. Damage. 

 The present species however is far more liable to severe injury than S. Narenga from both 

 early and late fires for the following reasons : — 



(a) It usually occurs on sandy soil. In areas which are burnt, the rain washes away 

 such soil from the base of the clumps, more or less exposing the base of the 

 culms and the rhizome branches from which the young culms are developed. 

 Such soil also rapidly dries after the rains and the base of the clumps, which 

 as noted above are more or less exposed to the sun and wind, also become dry, 

 as do the dead leaves and debris contained in the clump. There is therefore 

 a far greater danger of the fire penetrating to the base of the clump and des- 

 troying not only the first year culms, but also the rhizome itself. On loam 



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