458 GnA-VTIA^EAF.. AVF.NA. TniSTACIIYA. 



fert praclorea: foliis anifuslioribns ; glumis mngis inacqiiali- 

 bus, inagis comprcssis , pallidiorihus, c.irina acutioiihus la- 

 tcribus planis , anguslioribus , m.igis acurninatis, nervis (in 

 infcriorc suboctonis , in superiore novenis , ut in iil.-t) minus 

 proniiiiulis (unde latera glumae in hac acfpialia, in illa 

 [A. fatua] suhcostata); tum villis ilosculoruni longiorihus 

 alhis , ntc (lcmuni fulvcsccntihus. 



Obscrv. Utrum sit vere indigena nova orhi , an cum 

 cercalihus llispanicis vel liusiianicis illata , in duhio est re- 

 linquendum. 



LXIII, TRISTACHYA. f 



Splculac biflorac, flosciilo infcriorc nciitro (vcl 

 masculo); supcriorc hcrniapliroclito. Gluma inferior 

 brcvior , apicc mucronata. Flosculi hcrbacci , ncu- 

 trius valvula infcrlorc aplcc trldcntata, hcrmaphro- 

 dltl ])asl barbatl bHida, arlsta basi tortlll intcrjccta. 

 Lodlculac compllcatac. Caryopsls vcstita. 



Inllorcsccntla : panlcula simplcx, ramis aplce 

 triflorls. 



Char. naturalis. Spiculac (nostrls in spe- 

 ciebus magnae, in ramorum panlcidac apice tcrnac, 

 brevisslmc pcdlccllatac) j lanccolatac. Calyx biglumlsj 

 flosculis longlor, glumis altcrnis lanccolatis obtuse 

 carlnatls attcnuatis hcrljaccls : infcrlore paulo bre- 

 viorc in qulljusdam apicc trldcntata dentc mcdlo lon- 

 giorc , in aliis spccicbus intcgra magisque attcnuata, 

 scmpcr ncrvls tribus crassls costata 3 supcriore sub- 

 acuta subbidcntata trincrvi. FIosculus infcrlor ncuter, 

 bivalvls , conslstcntla hcrbacea glumac superiori siml- 

 lis, valvida Inferiore gluma inferlorc parum breviore 

 lanceolata concava trinervi aplce tridcntata dente 

 medlo longlore vel integra, superiore \ brevlore lan- 

 ceolata planluscula apice bifida , basi subcartllaginea, 

 utrlnque reilcxa. Fioscidus hcrmaphrodltus neutro 

 duplo fcrc brevior oijlongus, valvulis sul)cartllagl- 

 neis: inferior valvula superlorem involvens, oblonga, 

 convcxa , undecimncrvis, nervls deorsum delDlliorlbus 

 altcrnisqnc al^breviatls, aplce profundc blfida, lacl- 

 nlis luaccolatis strlctis, arista e sinu apicls orta callo 

 imposita longa crassa basi tortlll, in nonnullis abortu 



