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 : 250

Key to the species of Parahyparrhenia in the world

1. Upper glume of the sessile spikelet aristate; lower glume grooved, not convex on the back ............................................................2

1. Upper glume of the sessile spikelet ex-aristate; lower glume grooved or convex on the back..........................................................5

2. Homogamous spikelet present at the base of raceme; lower glume of sessile spikelet bidentate or entire .......................................3

2. Homogamous spikelet absent at the base of raceme; lower glume of sessile spikelet bimucronate.................................................... ..................................................................................................................................................... P. siamensis (endemic to Thailand)

3. Upper glume of the sessile spikelet bi-lobed, arista from sinus; lower floret entirely absent; lower glume of pedicelled spikelet longitudinally grooved; callus of pedicelled spikelet stipe-like, ca. 2 mm long ......................... P. laegaardii (endemic to Thailand)

3. Upper glume of the sessile spikelet acute to aristate, not bi-lobed; lower floret epaleate, barren; lower glume of pedicelled spikelet never grooved; callus of pedicelled spikelet never stipe-like, ca. 1.3 mm long.................................................................................4

4. Annual or ephemeral; awn of a fertile lemma robust, 35–100 mm long (an extremely variable taxon) ............................................. ............................................................................................................................................................... P. annua (endemic to Africa)

4. Perennial; awn of a fertile lemma not robust, 27–30 mm long ......................................................... P. perennis (endemic to Africa)

5. Lower glume of sessile spikelet with a longitudinal groove, apex entire or bi-dentate .....................................................................6

5. Lower glume of sessile spikelet dorsally convex not grooved, apex tridentate .......................... P. tridentata (endemic to Thailand)

6. Annual, up to 30 cm high; basal sheaths not bulged, glabrous; leaf blade short, granulate, 2.5–6.0 × 0.1–0.15 cm; ligule lacerated membranous; anthers 0.5–0.8 mm long ..................................................................... P. khannae (narrow endemic to Central India)

6. Perennial, up to 65 cm high; basal sheaths bulged, dorsally strongly villous or bearded with appressed or spreading white hairs; leaf blades long, smooth not granulate, 5.0–45 × 0.1–0.4 cm; ligule biseriately ciliate; anthers 2.8–3.0 mm long ............................ ......................................................................................... P. bellariensis (narrow endemic to Gandikota Fort Hill , Andhra Pradesh)