J > 



402 CONTRIBUTIONS FROM THE NATTONAT. IlERnAHl UM 



2. Dichroniena radicans Sclil('<*li1, & Charn. T.iiinaoa 6: ;iS, ISI^l. 



Dichromena pnhcra Vahl, Emun. 2; 2U, I80G, in part, 



Divkromenn puhera nilcrocarpa BoockL Liniuica 37: 529. 187o. 



DisTUiiuiTiox: Cciiinil Amt'rica, tropical Soutli Amt'i'ira; also in the West IndieSj 

 (jiiiU? coiunion. 



Costa Rican collection: San llafacl de Cartago, PiUiir 2583, 



13, RYNCHOSPORA Vahl. 



Glumes in many spirals or else obscurely 2-ranked; 3 or more of the Inwer empty, 

 1 1(> several above thes(^ bisexual and nut-bearing, the uppermost staminate or empty; 

 hypogynous bristles sometimes -wanling. when presents or 7, irregular; stamens 3 or 

 2, anterior; style bifid, in the series of th(^ IIaph.>styk'ac very long, at apex shortly 

 bidentate, in the series of the Diplostyleae deeply cleft, the branches linear; nut obo- 

 void, compressed, crowned with the conical and persistent style base. — Infl(yre8cence 

 capitate or panicled, near umbellate. Leaves always obvious, linear. 



KEY TO THE SPECIES. 



Style long; the two branches short, or almost noTH\ (llAn.osTYLEAE.) 



Stem monocephalons. (Moxocefhalae) 1. R. glohosa. 



Heads globose, several, rarely but one. {PoLYCEruALAE"). .. 2. H. njperoidcs. 

 Spikelets solitary or fascicledj disposed in corymbs. (Ca- 



LVn'ROSTYLE AE . ) 



Sjiikt^lets yellow, or yt^llow-brown 3. /?. aurca. 



Spikelets from greenish to chestnut brown. 



Stemdeavesmany, approximat(^; In-islli'siutne .... t. /?. jiohjphylhi. 

 Stems less densi^ly h^afy; bristles often obvious. 

 Spik(^lets green^ or somewhat (hestnut tinged. 



Spikelets 7 to 8 mm. long. , . 5. R. achiedeana. 



Spik<*lets 3 to 4 nun. h>ng 0. R, looi.pJiH, 



Spikelets chestnut-brown or tawny. 



lirisih^s of about the lentrlh of llu' miL . 7. A\ macrochacia. 



Eristh^s longer than the very small nut 8. R. vnicani. 



Style linear; branches 2, lini^ar, longer than the undividet! part. 



(DirLOSTYLEAE.) 



[?risth^s none. (Psilostachys.) 

 Nut transvers<dy undulate. 



Style bast^ depressed, nearly discoid _ 9. R. eximia. 



Style base pyramidal ^ 10. R. rohusta. 



Nut smooth, not undulatt^ 



Spikelets 9 mm. long _ ] ] . R. lompsphata 



Spikelets 2 tn 3 mm. long J2. R. clarkei. 



Bristles scabrous anteriorly; nut smooth; Innid solitary, 1 to 

 4 cm. long. (Fuscak) 13. R. vcphalotes. 



Bristles scabrous anteriorlv; nut transversely nn<lnlate, 

 (Glaucae.) 



Spikelets more or less fasci<led in the corymbs. 



Peduncles of the corymbs ^h^ider, nodding 14. 7?. (jJauca. 



Pedun<*les of the (^orymbs strictly erect- . . . , 15, R. firhaffrirri. 



Spikidets mostly soHuiry IH. 7?. rnarisrffliis. 



1. Rynchospora globosa Uoem. <t Schult. Sy.st, 2: =S<). 1S17. 

 (liaetospora ylobosa TI. li. K. N<iy. Gen. & Sp. 1: 230. 1815. 

 S rhoeni t s (jlohosa Foiw Ent^yc. Suppl. 5: r)17. 1817, 

 (^ephaloschoemis glohosffH Nees, Linna(^a 9; 2!)(>. 1834, 

 <'('j)h(ilosrhoenus inan/inafus lA{A)}n. Dansk. Vid. Sel^k. Skr. 2; <'i3. 1849. 

 Rynrhospnra innrginata Htend. Syn. PI. Glum. 2: 142. 1855. 



