41. Outer glumes 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 1. Northern part of Central Africa. =Latipes= Kunth Outer glumes compressed and keeled, not bearing hooked spines. Flowering glume broad, 3-nerved, mucronate or shortly awned. Stigmas long, short-haired all round.--Species 5. North Africa. Used as ornamental or fodder-plants. “Foxtail grass.” (Including _Colobachne_ Beauv.) =Alopecurus= L. 42. (34.) Joints of the rachis much thickened, forming, together with the appressed or adnate pedicels of the stalked spikelets, hollows 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 (_Ophiurus_) reduced to the adnate pedicel and therefore apparently absent. [Subtribe ROTTBOELLIINAE.] 43 Joints of the rachis not much thickened, nor forming hollows for the reception of the spikelets, rarely slightly concave, but then flowering glumes of the sessile spikelets awned or (_Elionurus_) the lowest outer glume membranous or papery and marked with two transparent balsamiferous streaks. 48 43. Lower outer glume awned or tailed, at least in the stalked spikelets. 44 Lower outer glume neither awned nor tailed, rarely tailed in the terminal spikelet only. 46 44. Lower outer glume with a long tail (or soft awn). Racemes digitate. Aquatic herbs.--Species 1. Central Africa. Forming the chief element of the grass-barriers (sudd) of the upper Nile. =Vossia= Wall. & Griff. Lower outer glume with 1-2 short awns, or in the stalked spikelets with a long awn, in the sessile awnless. Racemes solitary or arranged in racemes. 45 45. Lower outer glume with 1-2 short awns. Joints of the rachis horizontally truncate without an appendage.--Species 7. Central Africa. Used for plaiting-work. (_Rhytidachne_ Hack., including _Jardinea_ Steud.) =Rhytachne= Desv. Lower outer glume in the sessile spikelets awnless, in the stalked ones with a long awn or tail. Joints of the rachis obliquely truncate with an appendage at the tip.--Species 5. Central and South Africa. =Urelytrum= Hack. 46. Lower outer glume globular, pitted. Leaves cordate at the base.--Species 1. Tropics. Used in medicine. (Including _Hackelochloa_ O. Ktze.) =Manisuris= Swartz Lower outer glume more or less ovate, flat or rounded on the back. 47 47. Stalked spikelets reduced to the adnate pedicel and therefore apparently absent.--Species 1. Northern East Africa. (Under _Rottboellia_ L. fil.) =Ophiurus= Gaertn. Stalked spikelets containing a male flower or reduced to empty glumes.--Species 15. (Including _Hemarthria_ R. Br.) =Rottboellia= L. fil. 48. (42.) Sessile spikelets 2-flowered, the lower flower male, the upper male or hermaphrodite. Stalked spikelets 1-2-flowered or reduced to empty glumes. 49