Parahyparrhenia, A. Camus, 1950

Landge, Shahid Nawaz & Shinde, Rajendra D., 2022, A taxonomic revision of the genus Parahyparrhenia (Poaceae: Andropogoneae) in India and review of African and Thai species, Phytotaxa 541 (3), pp. 247-260 : 249-250

Key to genera allied to Parahyparrhenia

2. Sessile spikelet inserted within a cavity at apex of a rhachis internode; apex of internode dentate or not........................................3

2. Sessile spikelet not inserted within a cavity at apex of a rhachis internode; apex of internode never dentate ..................................7

3. Raceme solitary; pedicel and rhachis internode clavate or bucciniform............................................................................................4

3. Raceme bi-nate, rarely digitate; pedicel and rhachis internode stout (pyriform in Andropogon burmanicus ) ..................................6

4. Pedicel bucciniform; pedicelled spikelet much longer than their sessile counterparts; upper glume aristate .................... Diectomis

4. Pedicel clavate or linear-clavate; pedicelled spikelet slightly shorter or equal to their sessile counterparts .....................................5

5. Inflorescence a spiciform-raceme, variously disposed as: simple, compound, paniculate, globose, fastigiated, scanty or linear forms; racemes mostly subtended by a spatheole or an un-specialized sheath; delicate annual to moderately tough grasses ............ ..................................................................................................................................................................................... Schizachyrium

5. Inflorescence not various, composed of only a solitary, spiciform-raceme; raceme not subtended by a spatheole or a sheath; mostly tough grasses ........................................................................................................................................................................... Sehima

6. Aromatic grasses; inflorescence dense, decompound panicle; raceme bi-nate, never digitate, deflexed at maturity, borne on flat, sub-equal raceme bases .................................................................................................................................................. Cymbopogon

6. Non-aromatic grasses; inflorescence not dense, decompound panicle; raceme bi-nate or digitate, not deflexed at all, borne on terete, un-equal raceme bases .................................................................................................................. Andropogon (sensu stricto)

7. Pedicel and rhachis internode with a distinct translucent groove (resinous channel) .................................................... Bothriochloa

7. Pedicel and rhachis internode without a translucent groove, if at all channeled then without a translucent membrane ..................... ........................................................................................................................................................................................ Dichanthium

8. Callus of a pedicelled spikelet long and extended deceptively resembling the pedicel; pedicel very short almost reduced to a stump at the base; pedicelled spikelets over-lapping and subtending sessile spikelets; upper lemma of sessile spikelet entire .................... ........................................................................................................................................................................................ Heteropogon

8. Callus of a pedicelled spikelet short never extended; pedicel always well developed; pedicelled spikelets not subtending sessile spikelets; upper lemma of sessile spikelet bi-lobed ...........................................................................................................................9

9. Sessile spikelets inserted within the cavity of a cupuliform apex of a rhachis internode ........................................... Diheteropogon

9. Sessile spikelets not inserted at the apex of a rhachis internode ......................................................................................................10

10. Lower glume of the sessile spikelet convex or rarely slightly concave on the back or with two or more shallow striations but never a longitudinal groove; upper glume obtuse, acute, mucronate or aristate ........................................................................................11

10. Lower glume of the sessile spikelet with a characteristic longitudinally groove in the middle (see Parahyparrhenia tridentata ); upper glume acute to aristate not mucronate....................................................................................................................................13

11. A pair of homogamous spikelets forming an involucre at the base of racemes ................................................................... Exotheca

11. Homogamous spikelets present (rarely absent) but not forming an involucre at the base of racemes.............................................12

12. Callus of pedicelled spikelet stipe-like; upper glume of sessile spikelet aristate (ex-aristate in E. androphila ); raceme not deflexed (deflexed in E. archaelymandra )....................................................................................................................................... Elymandra

12. Callus of pedicelled spikelet not stipe-like; upper glume of sessile spikelet ex-aristate; raceme deflexed at maturity (in few not deflexed at all) ................................................................................................................................................................ Hyparrhenia

13. Raceme-bases produced at the tip into a long scarious vestigial appendage; racemes (1–) 2 (–10) awned per pair ........................... .......................................................................................................................................................................................... Hyperthalia

13. Raceme-bases without any distinct appendage (see some forms of Parahyparrhenia annua ); racemes 4–14 awned per pair........... ................................................................................................................................................................................. Parahyparrhenia