TRIANDRIA—DIGYNIA.

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ovato-lanceolats , concavae , acuminatae , aut acutae , alinea dimidia ad sesquilineam longae , carinatae , cari-na viridi, aut tota, aut superne ciliato-scabra , raronuda, lateribus glabris, aut sub fortiori lente minu-tissime puberulis , viridi-pallentibns , aut albido-pur-purantibus . Gluma corollina bivalvis , membranacea ,mutica, glabra, initio albo-viridula, demum dealbata.Valva exterior calyce quidquam brevior, oblonga, con-cava , quinquenervis, obtusa, atque a nervis produ-ctis plus minus manifeste denticulata, dentibus sub-inde brevissime setaceis, saltem uno alterove, et prae-sertim medio . Interdum quoque nervus medius hujusvalvae paulo infra apicem ejus sejungitur ab illa , etabit in setulam brevem, scabram, nuliimode articula-tam , prout aristae Agrostidum est . Penicillus brevis-simus pilorum utrinque unus ad basim hujus valvaeprope ejus marginem . Valva corollina interior dimidiobrevior, angustior, binervis, apice bidentata . Caryo-psis libera.

Varietas @ dilfert tantum, quia flosculi aristati sunt in-termixti flosculis muticis, scilicet gluma corollina majorinterdum ex dorso paulo supra basim emittit aristamarticulatam, infra articulum contortam, superius sca-bram , ipsa valva circiter duplo longiorem, arefactioneTefractam.

Varietas d fit vivipara , corollis in bulbillos elongatis,extra calycem productis .

Varietas "jf nunc pumila culmo digitali, nunc plusquampedalis, qui lusus subinde habentur in eodem csspi-te . Caryopsis ejus corrumpitur ustilagine, et fit tur-gidula, nitida, mucronulata, at semper intra calycemcontinetur.

Nullum dubium est, Agrostidem albam L. esse levissi-mum lusum Agrostidis vulgaris Smitli. , ut jam innuiin Amcen. Ital. p. a. 3 ., ad quas lectorem nunc ani-mando . In eamdem sententiam nuperrime ivit etiamLinkius in Hort. reg. Berol. descript. 1. p. 78., et in il-lam pronus videtur Hookerus , cum ait : I knou> not

/ of any British awlness Agrostides, which may not bereduced either to A. vulgaris or A. alba. The two spe-cies are indeed very closely united Brit. FI. p. 34. Quodsi Smithius pro speciebus diversis retinet: I concurwith Prof. Hooker ohd M.r Bicheno in uniting A. sto-lonifera to A. alba, but by no means in perceivingany ambiguity between the latter and vulgaris Engl.