552 GBAMiNE-s; Tristachya. 



Hab in arenosis siccis desertorum, Egyptus circa Alexandriani (Del., Ehr! 

 Auch ! etc), littorale Arabicum prope Kosser (Schw !), Arabiae Petre^e planities 

 Ramla (Boiss!), Persia prope Kaschan (Buhse!), 



Ar. Geogr. Africa borealis inferior, Arabia felix. 



TRISTACHYA (Nees io Mart. Bras. II, 459). 



Spiculse bifloroe terntp in apice ramulorum congestaeet subsessiles, 

 intermedia ssepc effeta. Glumae lanceolalae trinerves membranacejse. 

 Floscuius inferior sessilis maaculus vel neuter glaber glumella glu- 

 mis simili sed plurinervia, palea binervi. Flosculus superior herma- 

 phroditus basi pilosus glumella inferiore apice bifida inler dentes 

 longe arislata coriacea cylindrico-convoluta superiorem dorso sul- 

 cato-binervcm amplectente. Arista articulata partc inferiori spiraliter 

 torta. Squamulffi binse carnosse subintegrae glabra?. Slamina 2-3 

 antheris elongatis. Styli 2 elongati glabri, stigmata plumosa. 

 Caryopsis oblonga suicata glumellis corticata. — Ilcrbae perennes 

 facie Danihonice vel Triseti. 



\. T. barbata (A. Br. Flora 1841, p. 714 sub Loudetid) peren- 

 nis glauca adpresse velutina elata cespitosa, rhizomate caulibus- 

 que inferne induratis sublignosis squamatis ramosis, culmis erectis 

 oligophyllis, foliis breviter lanceolato-linearibus rigidis inferioribus 

 confertis patentibus subpungentibus, caulinis longioribus, vagina ad 

 pilorum coronam reducta, paniculcecontractoe ramis strictis solitariis 

 vel geminis, glumis lanceolalis acuminalis imequalibus minute velu- 

 tinis, glumella hermaplirodita apice longe bisctosa adpresse hirsuta 

 superne pilis rigidis dcnsis selas dimidias ffquantibus penicillata, 

 arista valde torla et geniculata glumis et setis duplo longiore %. T. 

 barhata Nees loc. cit. — Sorghwn harhalwm Hoclist. et St. 



Hab. in littore Nubico et prob. yEgyptiaco maris Rubri (Schweiuf. loCil 

 1542 !). 



Ar. Geogr. Arabia felix prope Ferihe (Schimp. 788 !). 



2. T. Stocksii, perennis glauca breviter vclutina, rhizomate 

 caulibusque inferne induralis ramosis, culmis ercctis gracilibus oligo- 

 phyllis, foliis brevissimis rigidis pungentibus patentibus infcrioribus 

 confcrtis lanceolatis culmei.s angustis, vagina ad pilorum coronam 

 reducta, panicula brevis subcontractoe ovatae ramis strictis solitariis 

 vel geminis, glumis lanceolatis ina:!quaiibus glabris, glumclla Iicrma- 

 phrodita apicc biselosa undique longe hirsuta superne pilis rigidulis 

 dcnsis sctis a^quilongis penicillata, arista gcniculata ct torta glumis 

 subduplo iongiore c^. 



Hab. in Belutschia et Scinde (Stoclis 1141 etC48!). 



AfQuis T. barbatce a qua differe videtur culmis tenuioril)US, foliis cuhneis 

 angustis, spiculis minoribus, arista minus robusla et subbreviore, pra^^sertim 

 glumellui pilis terminalibus ejus setas a^quanlibus nec duplo brevioribus. 



