HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. 7& 



These culms vary in size from the largest which have had the benefit of a complete season 

 of vegetative activity to the young buds which commenced their development towards the 

 close of the season of vigorous growth in September — November. 



If one of the larger of these shoots is looked at more closely it will be found to consist 

 of a short hard basal portion of mature culm measuring usually I — 2 inches in length and 

 with as a rule 12 (9 — 16) short internodes which are clearly defined by the insertions of the 

 leaves. The leaves inserted on the nodes of this piece of culm are more or less dead and 

 withered and can be readily stripped from the nodes of the hard culm on which they are 

 inserted. Inside these we find one or two not yet fully developed green leaves and finally in 

 the centre is the terminal growing point of the culm situated about 0-25 inch about the 

 upper node of the mature basal portion of the culm. 



The first two leaves produced at the extreme base of the culm are scales, or at all 

 events, have no obvious green lamina and omitting these it will be seen that the short piece 

 of culm matured during the first season's growth carries, as a rule, 10 leaves. Growth is 

 resumed with more or less vigour in February and towards the end of that month young 

 culms may often be found in which the apical bud of the culm has been raised some 3 inches 

 above the surface of the ground owing to the growth and elongation of the upper immature 

 internodes. Towards the end of April culms have been collected in which all the inter- 

 nodes of the flowering culm can even then be clearly distinguished and in which the apical 

 bud has been raised 8 — 9 inches above the ground by the elongation of these internodes. 

 It is interesting to note also that this vigorous growth is taking place at a period when the 

 rainfall is very scanty. 



The total number of long internodes developed in the flowering culm is usually 10, 

 excluding the apical segment which terminates in the panicle. Thus we have here each 

 year an apparently constant average rate of growth corresponding to a single leaf for each 

 month of the season of vigorous growth from February — November. 



As an average culm which dies after flowering thus persists through two growing- 

 seasons the culms may be described as biennial. No case has been seen in which a flower- 

 ing culm has been produced in one season and the time of flowering is as a rule very con- 

 stant. 1 At the same time the exact period which an individual culm takes to complete its 

 cycle varies, owing to the fact that young culms may commence their development at any 

 time during the period of vegetative activity. For this reason also if a clump is examined 

 in the season of rest, the immature culms are found to vary in age and size from young 

 buds which havje recently commenced development to the culms of one full season's growth. 



An exceptional type of development is very frequently seen in this species as follows. 



After the usual number of short basal internodes which as a rule immediately precede 

 the production of the long internodes of the flowering culm, only a few long internodes are 

 found and then a second series of short internodes, after which follow the long internodes 



1 Rare cases of culms of this species and also of Erianthus Ravennce flowering in November, December and Jsmuarv have been 

 met with which indicate that under exceptional circumstances these species are capable of vigorous growth practically throughout the vear 



[ 73 ] 



