139. GRAMINE^. 



by a spathaceous leaf-slieath (spa- 

 theole), from which it is usually 

 oiily shortly exserted (peduncle 

 elongate in Andropogon apricns) : — 

 § Spikes not reduced to a central 



few-noded portion surrounded • 



by an involucre of male or neuter 

 spkts. : — 



il All pairs of spikelets similar to 

 one another : — 



* Spikes solitary in each spa- 

 theole :— 

 Joints and pedicels slender . 74. Hypogynium. 

 Joints and pedicels buccini- 

 form. Gen. 75, 76 . . 17. Schizachyriastrse. 

 ** Spikes geminate in the spa- 



theole . . . . .77. Andropogon,* 

 !| II Lowest pair of spkts. on one or 

 both of the geminate spikes 

 homogamous. Lowest joint 

 often much thickened. Pani- 

 cles decompound. Often aro- 

 matic grasses . . . .78. Cymbopogon. 

 §§ Spikes reduced to a central few- 

 noded portion surrounded by an 

 involucre of modified, male or 

 neuter, spkts. Gen. 79, 80 . 18. Themedastrse. 

 I. Spike reduced to three spikelets with a bulbous 

 ba.se on a slender peduncle in spathaceous 



panicles 81. Apluda. 



c. Spikes many-noded. Joints and pedicels or 

 at least the joints much swollen and often 

 forming a cylindrical axis in which glume i 

 is sunk iua'depression formed b^' the inter- 

 node and pedicel of the ped. spkt. Pedi- 

 celled spikelet sometimes entirely sup- 

 pressed. Gen. 82-86 19. Rottboelliastrse. 



3, Male and female spikelets in different inflores- 

 cences on the same plant or occupying different 

 parts of the same inflorescence ; females below, 

 often solitary with or without a rudimentary 

 ped. spkt., i-fld. Males in pairs, one sessile 

 the other pedicelled at the top of the inflores- 

 cence. Female lower glume or bracteole often 

 becoming hard or bony. Gen. 87-90 . . 20. Maydese. 



KEY II. TO GENERA IN THE GROUPS. 



Group 1. Bambuseae. Bamboos. 



A. Pericarp fleshy or crustaceous free from the seed :— 



Spkts. 1-fld., bracteate. Fruit beaked . . . .1. CepJialostacJiyum. 

 Spkts. 2-many-fld., 1 only usually fertile. Ovary hir- 

 sute at the tip 2. Dendrocalamus. 



B. Pericarp thin, adnate to the seed :— 



Filaments free. Spkts. 1-many-fld. Palea 2-keeled . 3. Bamhum. 

 Fil. connate. Spkts. few-fld. ' Palea or not keeled . -i. Oxyfenantheia. 

 Group 2. Arundinese. Reeds. 



A. Spkts. 3-7-fld. Rhachilla with very long hairs. Gls. 



glabrous 5. Fhragmite». 



B. Rhachilla with short hairs below the flg. gls. or 

 glabrous. Fig. gls. toothed and awned :— 



Gls. i and ii 1-nerved. Fig. gls. marginally hairy . G. Triraphis. 

 Gls. i and ii 3-nerved. Fig, gls. dorsally hairy . . 7. Arundo. 



* Andropogon and Cymhopogon both belong to the Andropogonasfrce and are very 

 closely allied. Indeed some Cymhopogon have none of the sessile and pedicelled 

 spikelets similar nor strictly homogamous. Tlie habit is however different. 



942 



