HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. 97 



number may vary from 8 — 18), then four long internodes and finally the apical length which 

 terminates in the panicle. 



The leaves on the basal nine internodes are usually scales with no green lamina, so 

 that the average culm produces nine leaves, with a more or less perfectly developed green 

 lamina. 



The average period of vigorous vegetative activity is believed to extend from February 

 to October and the majority of the young culms appear to commence their growth at the 

 beginning of the rains in June. 



During November — January there is, as a rule, a well-marked period of rest and if an 

 average culm is examined during this period it will be found to consist of a short hard 

 mature basal portion of about 18 short internodes, the upper four or five of which carry 

 more or less dead and withered large leaves. 



Within and above these are one or two not yet fully developed green leaves and finally 

 in the centre at the apex of the culm is the terminal growing point situated close above the 

 upper node of the mature basal portion. 



During the season November — January, therefore, the local grasslands of this species 

 show a multitude of short immature culms each of which looks like a tuft of leaves. 



The blades of the majority of the leaves of these culms are mature, spreading, fully 

 expanded, and reddish, or brownish, yellow in colour, while only one or two interior and 

 apical leaves are still immature, with their blades convolutely folded and green in colour. 

 This is the cause of the characteristic reddish brown colour of the grasslands in the cold 

 season where this species is dominant. Vigorous vegetative activity is usually resumed 

 the following February and the flowering panicles are produced in May — June. 1 



As the aerial culm dies after flowering, its average duration is about 12 months and it 

 may be described as annual. 



It will be noticed that the number of green leaves produced on the culm, viz. 9, corre- 

 sponds to the number of months' vigorous vegetative activity, viz. June — October in the first 

 year and February to May in the following year, while the culm completes its cycle of 

 development in nine months of vigorous growth. 



The above represents what is believed to be the average development of the savannah 

 form in the forest, but individual culms of course vary to some extent in the period of their 

 life cycle and in a plant of this form which was cultivated at Dehra Dun, on moist soil, 

 where activity was not checked at the close of the rains, a culm, regarding which dates 

 were recorded, actually completed its cycle in seven months from June — December. 



In the dwarf form characteristic of areas regularly grazed or mown, and also in the 

 marsh form, the number of green leaves produced on the culm is usually greater, i.e. from 

 10 — 12 which is perhaps the result of vegetative activity being possible during a greater 

 number of months in the year. 



1 In areas where the grass has been cut, grazed, or burnt, vegetative activity commences earlier than usual and flowering usually 

 takes place in March — April. The swamp-form of this species also usually flowers at the close of the rains, or in the cold scson. 



[ 97 '] 



