HOLE : SOME INDIAN GRASSES AND THEIR CECOLOGY. 81 



Glume II. — Subequal I. Oblong to oblong-lanceolate, brown, thinly coriaceous, apex 

 membranous, sub-acute or obtuse. 



A central keel, 3 — 5 nerved. 



Margins inflexed, ciliate. 



Dorsally glabrous or hairy below, puberulous above. Villi not overtop- 

 ping the glume. 



Glume III. — Subequal I. Oblong, hyaline, enerved, or with one or more partial 



basal nerves, ciliate. 

 Glume IV. — Similar to III, but slightly shorter, enerved or with a partial median 



nerve. 

 Pale — \ to \ IV, ovate to oblong, hyaline, enerved, ciliate. 

 Lodicules, two, cuneate, glabrous, 002 in. 



Anthers, three, 005 — 0-09 in. long, yellow or more or less spotted with purple. 

 Stigmas, two, 0-03 — 0-04 in. long, dark purple. 

 The hairy leaf -sheaths, the culms bearded at the leaf insertions, the narrow, purple, Field Ch arac- 

 very fragile, fruiting panicle and the dark green leaves readily distinguish this species in ters * 

 the field. 



B. — Taxonomy. 



59. Hackel divides the genus Saccharum 

 into four sub-genera, two of which contain all the Indian species. 



These two sub-genera (sections) have been adopted in the F. B. I. as follows : — 



I. Eusaccharum. — Rachis of spike (Hack, raceme) fragile. Spikelets of each pair 



subequal, sessile and pedicelled, both fertile (Hack. $ ). Stem solid. 



II. Sclerostachya. — Rachis of spike tenacious. Both spikelets of each pair pedi- 



celled. Stem fistular. 



Hackel places only one Indian species in the latter, viz. — 



S. fuscum Roxb. This is adopted in F. B. I. where a second Malayan species is also 

 added, viz. S. Ridley i which Hackel described after the publication of his monograph. 



The characters of the culm being fistular or solid and the rachis tenacious or fragile 

 are therefore seen to be of sectional rather than specific value. 



The flowering culms of the present species are very subject to damage by insects and 

 fungi. Culms which have been thus injured usually show a small perforation which is 

 apparently caused by some sucking insect, while the tissue of the culm in the neighbourhood 

 of the hole becomes discoloured and usually r'addish giving the appearance of the " red- 

 rot " of the Sugarcane. 



Specimens of the damaged culms were submitted to Dr. Butler, Imperial Mycologist at 

 Pusa, but although fungal hyphae were found in the discoloured tissue these apparently 

 belongted to a saprophytic species, as no parasitic fungus could be isolated on incubation. 



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