i 20 
GRAMIKEiE. 
Crescit in alta planitie Mexicana , inter Salamanca et Querelaro, ait. 900 hexap. 0 Floret 
Septembri. 
Culmus erectus, simplex, tripedalis, glaber. Folia plana, striata, externe glabra, interne pilosiuscula, 
margine scabra. Vaginae striat®, superiores scabriuscul®. Ligula elongata, glabra. Panicula ramosa, 
subverticillata, patula, subsecunda, novem- aut decempollicaris, apice subnutans, ramis rliachique 
scabris. SpiculjE triflor®, floribus omnibus fertilibus. Rhacliis spicul® albo-pilosa. Gluma; sub®quales, 
lineares, subulat®, carinat®, virides, glabr®, dorso scabr®, spiculam sub®quantes. Palea; in®quales, 
inferior lanceolata, concava, virescens, apice subquinquenervia, quadrifida, laciniis subulatis, dorso 
scabra et aristata; palea superior brevior,hyalina , binervia, apice bidentata, dentibus subulatis, margine 
scabriuscula. Arista tortilis, scabra, palea longior. 
5. AVENA TOLUCENSIS. t 
A. culmo superne pubescente ; foliis scabris; panicula coarctata, cylindracea ; glumis spicu¬ 
lant biiloram subeequantibus; paleis inaequalibus, inferiore majore, bifido-dentata, dentibus 
subaristatis; arista dorsali, reflexa. 
Crescit in apricis, frigidis, prope urbem Mexicanam Tolucca, ait. i38o hexap. % Floret 
Septembri. 
Radix fibrosa. Culmi c®spitosi, erecti, simplices, sesquipedales, striati, superne pubescentes, interdum 
glaberrimi. Nodi glabri. Folia plana, striata, utrinque scabriuscula, margine scabra. Vaginas striat®, 
glabriuscul®. Ligula laciniata , glabra. Panicula ramosa, coarctata, cylindracea , tripollicaris, ramis abbre¬ 
viatis, alternis, adpressis, rhacliique pubescenti-pilosis. Spiculas oblong®, biflor®, floribus duobus 
hermaphroditis. Glumae oblong®, acumiuato-subulat®, subaristat®, carinat®, obscure tri- aut quinque- 
nervi®, sub®quales, longitudine fere spicul®, glabr®, dorso scabr®, virescentes, apice purpurascentes. 
Paleas oblongo- lanceolat®, apice bifido-deutat®, dentibus subulatis, flavescentes, glabr®, dorso scabr®, 
inferior latior, paulloque longior, quinquenervia, superior bicarinata, hyalina, bidentata, dorso scabra. 
Arista dorsalis, reflexa, scabra, palea longior. 
4- AVENA ELONGATA. t 
A. culmo glaberrimo; foliis margine scabris; panicula coarctata, cjdindracea ; glumis spi¬ 
cula biflora brevioribus; paleis inaequalibus, bilido-dcntatis , dentibus subaristatis; arista 
dorsali, recta. 
Crescit in scopulosis montis Chapollepec prope urbem Mexici , ait. 119.0 hexap. Floret 
Februario. 
Culmus erectus, simplex, pedalis, striatus, nodique glabri. Folia linearia, striata, utrinque glabra, 
margine scabra, plana. Vagina; striat®, glabr®. Ligula glabra. Panicula ramosa, coarctata, cylindracea, 
subtripollicaris, ramis adpressis, abbreviatis, rliachique pubescenti-scabriusculis. Spicula, oblong®, 
biflor®, floribus duobus hermaphroditis, altero interdum abortivo. Gluma sub®quales, acut®, apice 
arista brevissima terminat®, carinat®, obscure quinquenervi®, virides, glabr®, dorso scabr®, spicula 
paullo breviores. Palea in®quales, apice bifido-dentat®, dentibus subaristatis, inferior latior et paullo 
longior, quinquenervia, viridis, glabra, dorso scabra, superior lanceolata, hyalina, bicarinata, dorso 
scabra. Arista dorsalis, recta, scabra, palea longior. 
Pr®cedenti valde affinis, sed diversa ; culmo glaberrimo, foliis margine scabris, glumis viridibus, arista 
dorsali recta. An. varietas Aven® tolucensis? 
b) Arundinacece. 
ARUNDO. R. Brown. 
Arundinis species. Linn. 
Spicula: multiflorae, floribus lana longa, persistente cinctis. Glumae duae. 
Pai jem duae , acaminato-subulatae. Stigmata penicelliformia. 
