* (frJL } (^3^'">'I^'zt N/sJu. . J 77 77 -^vu,'j^cc tr-i eu'VWy-Z^rr<^- - -7 — — - — ^ 7 ■ " f r * I Voi. IX. — Part L Price 10s. 6d. FLOE A OF TROPICAL AFRICA. EDITED BY SIR DAVID DRAIN, C.M.G., C.I.E., LL.D., P3.S. DIRECTOR, ROYAL BOTANIC GARDENS, KEW, PUBLISHED UNDER THE AUTHORITY OF THE SECRETARY OF STATE FOR THE COLONIES. 3 « B LONDON: L. EEEYE & CO. Limited, $ubltsfjers to lTje IRoine, Colonial anb LnUian Cobemnuuts, 6 HENRIETTA STREET, COVENT GARDEN. 1917. See I5* mt. 77 A 4 C,&. *1 / 0. (-S ^ jL- • - H' V rfau* ! \ u. /■ l'\d 4. ^ (fa. ffat.afa'd- £«»+* 3 3 ^>/a ,; -do? •• /j / (Py^-^z some- times <$ or neuter ; lower glume flat or somewhat convex and usually coriaceous below, charta- ceous and markedly nerved upwards, rarely shallowly concave ; keels frequently winged or marginate ... ... ... ... ... ... 3. Isch^emum. 2 6 Pedicelled spikelets represented by a linear curved pedicel ; lower glume coriaceous, convex, covered all over with transverse much raised ridges which are often broken up into teeth or warts, not keeled 4. Thelepogon. Racemes always solitary on the culms or branches. Glumes not winged, the upper of the sessile spikelet with a setose awn ; pedicelled spikelets flat, their lower glume strongly nerved ... ... 5. Sehima. Upper glume of both spikelets with a wing-like crest, muticous ; pedicelled spikelets rounded on the back with a large revolute wing from the keel of the lower glume ... ... ... ... ... 6. Andropterum. Only genus 6. Apludastrae. ... 7. Apluda. J 0^ c. Vossiastrae. Lower glume smooth. Lower glume of all spikelets long-caudate ; racemes digitate, occasionally solitary, somewhat com- pressed, very tardily disarticulating ; spikelets 2-flowered ... 8. Vossia. Lower glume of all or at least of the sessile spikelets ecaudate, muticous. Lower glume quite coriaceous, of the pedicelled spikelets produced into a long awn ; spikelets 2-flowered; racemes solitary ; paired or up to 5 on a common axis ... ... ... ... 9. Urelytrum. CLVII. GRAMINEiE (Stapf). 9 Lower glume of both spikelets of each pair muti- cous, coriaceous near the keels, otherwise thinly chartaceous ; spikelets 1 -flowered ; racemes panicled, very fragile 10. Thyrsia. Lower glume muricate ; racemes panicled or race- mosely arranged on a long common axis ; spike- lets 1 -flowered 11. Jardinea. d. Rottbcelliastrae. Spikelets all alike, also as to sex ; racemes tough or tardily disarticulating, much compressed ; joints and pedicels fused 12. Hemarthria. Spikelets of each pair more or less dissimilar, at least as to sex, the pedicelled & , neuter or suppressed. Sessile spikelets small, globose, foveolate, 1 -flowered, pedicelled very dissimilar; joints and pedicels Jj fused; racemes conspicuously dorsiventral ... 13. Manisuris.' Sessile spikelets not globose. Sessile spikelets much compressed, winged from the transversely rugose or muricate lower glumes, 1 -flowered, pedicelled very dissimi- lar; joints and pedicels fused ; racemes con- spicuously dorsiventral ... ... ... 14. Peltophorus. Sessile spikelets not winged. ~ ; ■ ■ Racemes usually more or less villous, very rarely glabrous, never cylindrical ; joints and pedicels moderately stout, gaping. Spikelets 2 -flowered, very villous all over, the sessile sometimes 2 at a node and sub- opposite ; lower glume without trans- parent oil-ducts or penicillate warts ... 15. Lasiurtts. Spikelets 1 -flowered ; racemes more or less villous from the joints and pedicels or the edges of the spikelets, rarely glabrous ; lower glume with a transparent oil-duct inside each keel or a fringe of penicillate warts 16. Elyonurtjs. Racemes glabrous, cylindrical, particularly when the spikelets are closed. Pedicels and joints fused. Racemes stout, few from each culm, sessile spikelets 2 -flowered, pedicelled 3 or neuter 17. Rottbcellia. *7 Racemes slender in ample spatheate pani- cles ; sessile spikelets 1 -flowered ... 18. Opiiitmcrs. Pedicels free from the joints. Pedicels and joints cupular-clavate, gaping, exposing between them the upper glume (which is covered by the accum- bent pedicelled spikelet) ; spikelets of each pair similar, 2 -flowered ... ... 19. Chasmopodium. Pedicels and joints posticously contiguous ; pedicelled spikelets usually much re- duced or quite rudimentary. Racemes usually in terminal and lateral 10 CL VII. GRAMINEiE (Stapf). spatheate fascicles or fastigiate pani- cles ; spikelets 1 -flowered ; coarse tall grasses ... ... 20. Ccelorrhachis. Racemes solitary and terminal on 1- or few-noded culms ; sessile spikelets 2 -flowered ; back of lower glume usually transversely rugose ... 21. Rhytachne. e. Saceharastrae. Rhachis of racemes continuous at the nodes and tough, or tardily disarticulating, all spikelets pedicelled. Racemes in spike-like or thyrsoid solitary panicles, rhachis quite tough ; spikelets muticous ; glumes delicate or somewhat firm at the base... 22. Imperata. Racemes in large, often reddish or brownish panicles, rhachis tough or tardily disarticulating ; spike- lets awned ; glumes chartaceous to coriaceous 23. Miscanthidium. Rhachis of racemes readily disarticulating ; spikelets paired, one sessile, the other pedicelled. Glumes coriaceous or chartaceous throughout ; pani- cles narrow, fulvously to rufously villous or tomentose ; spikelets always muticous, the pedicelled $ 24. Eriochrysis. Glumes membranous or chartaceous to subcoria- ceous at the base ; panicles wide, often thyrsoid, more or less plumose and silvery ; spikelets usually awned, rarely mucronate or awnless ; awn a straight, rarely bent not twisted bristle 25. Saccharum. ^ CJ- /. Polliniastrae. Spikelets dorsally compressed ; callus short, obtuse ... 26. Eulalia. Spikelets subterete ; callus long, pungent ... ... 27. Homozeugos. g. Sorghastrae. Spikelets dorsally compressed (at least when in flower) ; lower glume of the fertile spikelets firmly charta- ceous to coriaceous. Spikelets in threes, one of them fertile, or in racemes of 2-8 pairs ; the pedicelled 3 , neuter or if quite suppressed then at least the pedicels present . . . 28. Sorghum. Spikelets solitary ... ... 29. Cleistachne. Spikelets laterally more or less compressed. Racemes of many pairs of spikelets ; primary branches of panicle in whorls of 6 to 20 ... 30. Vetiveria. Racemes usually reduced to 1 sessile $ and 2 pedi- celled 3 or barren spikelets, rarely of 2 or more but always few pairs ... ... ... ... 31. Chrysopogon. h. Arthraxonastrae. Only tropical African genus ... ... ... ... 32. Arthraxon. /6 i. Hypogyniastrae. Only tropical African genus ... ... ... ... 33. Hypogynium. CLVII. GRAMINEA5 (Stapf). 11 j. Amphilophiastrae . Racemes in compound espatheate panicles Racemes not in compound espatheate panicles. Racemes digitate, or many racemosely arranged on a common axis shorter than the racemes. Sessile spikelets of all pairs $ , awned 34. Capillipedium. 35. Amphilophis. !'7 Sessile spikelets of the lowest 1-3 pairs £ or neuter and awnless. Racemes shortly or very shortly peduncled, not nodding; joints and pedicels solid; anthers . ... . of $ and $ alike 36. Dichanthium. * / Racemes borne on subcapillary peduncles, which are up to over ^ in. long and usually nod- ding or sigmatoid ; joints and pedicels hyaline and balsamiferous between the thickened margins ; anthers of £ minute, about as long as broad, of £ several times longer than broad 37. Euclasta. Racemes solitary at the ends of the culms and branches, sometimes in scanty spatheate false panicles 38. Eremopogon. Jc. Schizaohyriastrae. Pedicelled spikelets not conspicuously larger than the sessile, very often smaller to very small ; upper glume awnless 39. Schizachyrium. / Pedicelled spikelets very much larger than the sessile, almost concealing them ; upper glume awned ... 40. Diectomis. ’’ l. Andropogonastrae. Racemes mostly 2-nate or sometimes digitate at the end of simple or almost simple culms, rarely on the more or less fastigiate branches of a spatheate false panicle ; usually all pairs heterogamous and all sessile spikelets $ and alike, or sometimes (mainly § Piestium) the lowest more or less reduced and barren, but still resembling the upper fertile spikelets ... ... 41. Andropogon. Racemes always 2-nate, with a spathe supporting or surrounding each pair, gathered into often much decompound spatheate panicles ; the lowest pair of one of the racemes homogamous, £ or neuter ; all pairs of the other heterogamous ; mostly aro- ;v matic grasses ... 42. Cymbopogon. I m. Hyparrheniastrae. Lower glume without a' herbaceous beak ; pairs of racemes usually in much compound spatheate panicles ; racemes few- to many-noded, only one of them or both with 1 (rarely 2) homogamous pair, the pedicelled member of which is very similar to the sessile ... 43. Hyparrhenia.