1	Lemmas 5-nerved, the 2 lowermost barren and resembling the glumes		Tetrachne
+	Lemmas 3(-5)-nerved, the lowermost fertile		(2)
2 (1)	Lemmas usually entire at the apex, obtuse, acute or acuminate, sometimes mucronate, or if 2-toothed (Acrachne) then glabrous near the margins and along the side nerves; cleistogamous spikelets (cleistogenes) not developed in the axils of the leaf-sheaths		(3)
+	Lemmas usually emarginate or 2-4-toothed or lobed at the apex, rarely entire but then hairy along the nerves, frequently mucronate or awned		(12)
3 (2)	Glumes aristate or aristate-acuminate; spikelets sessile on the flattened branches of a narrow panicle, 2-3-flowered		Dinebra
+	Glumes obtuse, acute or acuminate, rarely the upper awned but the spikelets then in digitate spikes (Dactyloctenium)		(4)
4 (3)	Internodes of the rhachilla bearded at the tip with long hairs up to half the length of the lemma; spike-lets sub-sessile or shortly pedicelled on the erect branches of a contracted elongated panicle		Halopyrum
+	Internodes of the rhachilla glabrous or only shortly hairy		(5)
5 (4)	Spikelets in open, contracted or spike-like panicles		Eragrostis
+	Spikelets sessile or very shortly pedicelled, loosely to densely imbricate in digitate or racemosely arranged spikes or spike-like racemes, very rarely in solitary spikes		(6)
6 (5)	Lemmas softly villous all over; spikelets loosely imbricate in loosely panicled racemes		Orinus
+	Lemmas glabrous or shortly hairy in the lower part or on the nerves; spikelets closely to densely imbricate, biseriate		(7)
7 (6)	Axis of the spikes terminating with a sharp point; upper glume mucronate or awned; spikes digitate		Dactyloctenium
+	Axis and branches of the inflorescence ending in a spikelet		(8)
8 (7)	Lemmas ± rounded on the back or only slightly keeled above the middle; grain coarsely wrinkled, sub-globose, deeply hollowed out on the face		Coelachyrum
+	Lemmas acutely keeled		(9)
9 (8)	Spikelets falling entire at maturity from the axis of straight spikes, the latter numerous and crowded into a long narrow dense panicle; glumes 1-nerved		Desmostachya
+	Spikelets breaking up at maturity; spikes few to several		(10)
10 (9)	Spikes usually in pseudowhorls or scattered; lemmas with the lateral nerves running out into minute teeth and the middle nerve into a mucro or short awn		Acrachne
+	Spikes digitate or subdigitate; lemmas entire		(11)
11 (10)	Spikes persistent		Eleusine
+	Spikes deciduous at maturity		Ochthochloa
12 (2)	Spikelets in panicles or in racemosely arranged spikes or spike-like racemes		(13)
+	Spikelets in solitary terminal secund spikes or a pair of divergent or dorsally adpressed spikes (spikes rarely digitate)		(16)
13 (12)	Cleistogenes developed in the axils of the lower leaf-sheaths; florets exserted from the glumes; spikelets in lax panicles		Kengia
+	Cleistogenes not developed in the axils of the lower leaf-sheaths		(14)
14 (13)	Tall reed-like grasses with large dense plumose panicles; lemma hairy on the margins, the hairs as long as the lemma		Neyraudia
+	Spikelets in slender, ± secund, racemosely arranged racemes		(15)
15 (14)	Racemes loosely spiculate; spikelets linear-oblong, subterete; lemmas ± rounded on the back		Diplachne
+	Racemes mostly densely spiculate, conspicuously secund; spikelets oblong, laterally compressed; lemmas keeled		Leptochloa
16 (12)	All florets fertile; lowest lemma less than 4 mm long; lateral nerves and keels glabrous		Tripogon
+	Upper 1-3 florets sterile, reduced to empty lemmas; lowest lemma up to 6.5 mm long, shortly hairy on the lateral nerves and keel, or if less than 4 mm long then long-ciliate on the lateral nerves and keel		Tetrapogon