84 l6. GRAMINEAE 



36. Clusters of spikelets enclosed by a hard, urn-shaped involucre formed by 



the lowest outer glumes, Rachis of the spike wavy — Species 5. Central 



and South Alrica Anthephora Schreb. 



Clusters of spikelets without an involucre 37 



37. Clusters containing 2 — 4 fertile spikelets and a barren one. Outer glumes 



I — 2, the upper one with hooked spines oa the nerves. Kachis of the 

 spike glabrous. — Species 4. [Nazia Adans.) .... Tragus Hall. 

 Clusters containing i — 2 fertile and 2 — 3 barren, often awn-like spikelets. 

 Outer glume i, with rough nerves, avvned. — Species i. Southern West 

 Africa (Hereroland). ... Monelytrum Hack. 



38. Styles united at the base ; stigmas short, feathery. Outer glumes 2, 



glabrous, with a long awn or awnless. Flowering glume smaller. Spike- 

 lets diverging from the rachis. — Species 4. Tropical and South Africa. 



Used as fodder-grasses Parotis Ait. 



Styles free or the stigmas elongated and short-haired all round. . . 39 



39. Outei glume i, compressed, keeled, awnless. Styles free. Spikelets 



pressed close to the rachis. Leaves stiff. — Species i. Mascarene 



Islands. {Osterdomia Neck.) Zoysia Willd. 



Outer glumes 2 40 



40. Outer glumes subulate, with a long awn, short-haired. Flowering glume 



somewhat shorter, with a rather long awn. Pa lea slightly shorter 

 than the flowering glume, acuminate. Styles free. Fruit with a large 

 hilum. Spikelets in pairs. — Species i. Northern East Africa. 



Tetrachaete Chiovenda 

 Outer glumes and flowering glume with a short awn or awnless. . 41 



41. Outer glume>= convex, with hooked spines on the back, awnless. Flowering 



glume much shorter, unarmed or mucronate. Styles free ; stigmas 

 feathery. Spikelets with a flattened stalk. — Species i. Northern part 



of Central Africa Latipes Kunth 



Outer glumes compressed and keeled, not bearing hooked spires. Flower- 

 ing glume broad, 3-nerved, mucronate or shortly awned. Stigmas 

 long, short-haired all round. — Species 5. North Africa. Used as orna- 

 mental or fodder-plants. " Foxtail grass." (Including Colohachue 

 Beauv.) Alopecurus L. 



42. (34.) Joints of the rachis much thickened, forming, together with the 



appressed or adnate pedicels of the stalked spikelets, hollov.'S in which 

 the sessile spikelets are sunk. Flowering glumes awnless. Lowest 

 outer glume leathery or hardened. Sessile spikelets hermaphrodite, 

 stalked ones male or neuter, rarely {Ophiurns) reduced to the adnate 

 pedicel and therefore apparently absent. [Subtribe rottboelliixae.] 43 

 Joints of the rachis not much thickened, nor forming hollows for the recep- 

 tion of the spikelets, rarely shghtly concave, but then flowering glumes of 

 the sessile spikelets awned or {Elionurw^) the lowest outer glume mem- 

 branous or papery and marked with two transparent balsamiferous 

 streaks 48- 



