HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. Ill 



B. — Taxonomy. 



92. Hackel separates two species mainly by 

 the following characters :— 



Andropogon monticola, Schult. — Glume II of sessile spikelet keeled, the keel from 

 base to f or | its length densely pectinate ciliate with long rigid rufous hairs, shortly white 

 hispid in upper J. 



Andropogon Trinii, Steud. — Glume II of sessile spikelet keeled below the apex only, 

 keel white ciliate. 



Remaining § or f of the glume dorsally, not keeled, glabrous. 



In F. B. I., both of the above are included as varieties in one species named A . monti- 

 cola, Schult, and the author remarks : " I am unable to classify the varieties of this common 

 and variable plant in accordance with geographical areas on other considerations. This, if 

 possible, must be effected by field botanists in India. There is every gradation from the 

 coarsely hirsute keel of monticola, to the perfectly smooth of some states of Trinii." The 

 author, however, differentiates and describes an additional variety which he names robustus. 

 The latter is founded on a plant collected by Strachey and Winterbottom which shows the 

 basal § or -f of glume II of sessile spikelet more or less pectinately ciliate with white 

 hairs. All these three described forms appear to vary greatly, as regards their habit and 

 vigour of growth, in response to the moisture conditions of the habitat and also according 

 as whether, or not, the plants are habitually grazed, cut for fodder, or periodically burnt. 

 The colour of the cilia of glume II of the sessile spikelet (pale or white in robustus and 

 rufous in monticola), accordingly, appears to be the chief difference between monticola and 

 robustus, rather than any difference in the habit, and these forms appear to have different 

 and fairly defined areas of distribution (monticola occurring chiefly in Central and Southern 

 India, while robustus is mainly found in N. India, in the outer N. W. Himalayas and Sub- 

 Himalayan tract). In the F. B. I. the author includes under robustus a plant (No. 555 col- 

 lected by King at Goona, Central India), glume II of the sessile spikelet of which is dorsally 

 ciliate in the basal f with long rufous hairs and which appears to be referable rather to 

 monticola. In the locality with which the present paper is chiefly concerned the forms of 

 this plant which occur are robustus (taken in the narrow sense of Strachey and Winter- 

 bottom's plant alone) and Trinii. Both when studied with herbarium specimens and also 

 in the field, however, the local plant gradually and imperceptibly passes from typical 

 robustus to typical Trinii. It is believed that a similar passage takes plaee between monti- 

 cola and Trinii in Central and S. India. Further research, however, in the field is required 

 to establish this and also to decide whether monticola can be separated from robustus. For 

 the present it seems desirable to follow the F. B. 1. and to unite these forms into a single 

 species and this has been done in (A) above. So far as the local plant is concerned specimens 

 with the more hairy glume II tend to occur in localities where there is a scarcity of available 



[ HI 1 



