13 



Jour., Bom. Nat. Hist. Soc, Vol. XXXIV, No, 1 [March 1, 1930. 



longer than the florets ; floral glumes membranous, 

 often hyaline, that cf the upper floret usually 

 awned or reduced to an awn (Genera 5-41). 



1. Sub-tribe: Dimerince. — Spikelets homogam- 



ous, second on a slender inarticulate 

 rhachis, 1-flowered, diandrous (vol. 32, 

 18) ... ... ... ... 5. Dimeria. 



2. Sub-tribe: Ischcemince .— Fertile spikelets 2- 



flowered ; fertile floret awned from the 

 sinus of the bifid or bidentate upper floral 

 glume, sometimes awnless in Apluda 

 (Genera 6-13). 

 A. Group Ischcemastrce . — Racemes several- 



to many-noded, espatheate ; spikelets of 



each pair homogamous or more often 



heterogamous, usually similar in shape 



and nervation, rarely distinctly hetero- 



morphous ; fertile spikelets awned 



(Genera 6-12). 

 i. Margins of lower involucral glume of sessile 



spikelet inflexed. 



a. Stem not woolly below ; joints and 



pedicels stout ; spikelets heterogam- 

 ous (Genera 6-8). 



(1) Spikes clustered ; lower involucral 



glume not channelled (vol. 32, 19)... 6. Isch&mum. 



(2) Spikes solitary ; lower involucral 



glume usually channelled (vol.32, 



22) ... ... ... 7. Sehima. 



b. Rootstock and base of stem clothed 



with woolly sheaths ; spikelets similar 

 and homogamous (vol. 32, 25) ... 8. Pollinidiutn. 



ii. Margins of lower involucral glume of 

 sessile spikelet not inflexed. 



a. Spikes solitary ; spikelets 2-nate, 1-2- 



flowered, 2-awned (vol. 32, 289) ... 9. Pogonatherum, 



b. Spikes solitary or 2-nate ; spikelets 2- 



flowered, diandrous ; lower involucral 

 glume very broad truncate (vol. 32, 

 25) . ... ... ... 10. Apocopis. 



c. Spikes digitate ; spikelets 2-flowered ; 



lower involucral glume tubercled 



(vol. 32, 22) ... ... ... 11. Thelepogon. 



d. Spikes 2-oo-nate ; spikelets 2-nate, 



upper alone awned (vol. 32, 25) ... 12. Lophopogon. 

 B. Group Apludastrcs. — Racemes 1-noded, 

 reduced to 3 heteromorphous spikelets, 

 the sessile with a male and a herma- 

 phrodite floret and an inflated callus, 

 one pedicelled with 2 male florets, the 

 other rudimentary on a glume-like 

 pedicel ; fertile florets awned or awnless 

 (vol. 32, 26) ... ... ... 13. Apluda. 



3. Sub-tribe: Rotboellincz . — Fertile spikelets 



1- or 2-flowered ; fertile florets awnless 



(Genera 14-21). 



Group Rotboelliastrce . — Racemes at the 



ends of the culms and their branches in 



a false (rarely true') spatheate panicle 



or solitary and terminal on simple or 



sparingly branched culms. 

 A. Spikelets all alike, also as to sex ; racemes 



tough or tardily disarticulating, much 



compressed, joints and pedicels fused 



(vol. 32, 26) ... ... ... 14. Hgmarthria. 



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