GRAJIINE.E. (GRASS FAMILY.) 543 



5. S. serotinus. Smooth ; culms very slender, flatfish (8' -15' high), 

 few-leaved; leaves very slender, channelled; panicle soon much txserted, the dif- 

 fuse capillary branches scattered ; glumes ovate, obtuse, about half the length 

 of the palea;. (X? (Agr. & Vilfa serotina, Tore. V. tenera, Trin. Poa ? uni- 

 flora, Muhl. P. modesta, Tuckerm.) — Sandy wet places, E. New England to 

 New Jersey and Michigan. Sept. — A very delicate grass; the spikelets, &c, 

 smaller than in the last. 



7. AGBOSTIS, L. Bent-Grass. 



Spikelets 1-flowered, in an open panicle. Glumes somewhat equal, or the 

 lower rather longer, usually longer than the palese, pointless. Palea; very thin, 

 pointless, naked ; the lower S - 5-ncrved, and frequently awned on the back, the 

 upper often minute or wanting. Stamens chiefly 3. Grain (caryopsis) free. 

 — Culms usually tufted, slender. (Name from dypos, a field, the place of 

 growth.) 



\ 1. TRICHODIUM, Michx. — Upper palea abortive, minute, or none. 



1. A. data, Trin. (Taller Thin-Grass.) Culms firm or stout (2° -3° 

 high) ; leaves flat (l"-2" wide) ; upper ligules elongated (2"-3" long) ; spike- 

 lets crowded on the branches of the spreading panicle above the middle (H"long); 

 lower palea awnless, slightly shorter than the rather unequal glumes ; the upper 

 wanting. 1J. (A. Schweinitzii, Trin. ? A. altissima, Tuckerm., excl. var. laxa. 

 Trich. clatum, Pursh.) — Swamps, New Jersey and southward. October. 



2. At peWhssmais, Tuckerm. (Thin-Grass.) Culms slender, erect from 

 a decumbent base (l°-2° high); leaves flat (the upper 4'-6' long, l"-2" 

 wide) ; panicle at length diffusely spreading, pale green, the brandies short, divieled 

 and flower-bearing from or below the middle ; lower palea awnless (rarely short- 

 awned), shorter than the unequal glumes ; the upper minute or obsolete. \ 

 (Cornucopia? perennans, Walt. Trich. perennans, Ell. T. decumbens, Michx. 

 T. scabrum, Muhl., not Agr. scabra, Willd. Agr. anomala, Wi/ld.) — Damp 

 shaded places. July, Aug. — Spikelets, &c. as in No. 3, into which it appears 

 to vary. 



3. A. sefsfora, Willd. (Hair-Grass.) Culms very slender, erect (1°- 2° 

 high) ; leaves short and narrow, the lower soon involute (the upper 1' - 3' long, 

 less than 1" wide); panicle eery loose and divergent, purplish, the long capillary 

 branches flower-bearing at and near the apex ; lower palea awnless or occasionally 

 short-awned on the back, shorter than the rather unequal very acute glumes ; the 

 upper minute or obsolete, y. "Z 1 (A. laxiflora, Richard. A. Michauxii, Trin. 

 partly. Trich. laxiflorum, Michx. T. montanum, Ton:) — Exsiccated places, 

 common. June, July. — Itemarkable for the long and divergent capillary 

 branches of the extremely loose panicle ; these are whorled, rough with very 

 minute bristles (under a lens), as also the keel of the glumes. Spikelets 1' 

 long. — A variety"? from about the White Mountains, &c. (var. montana, 

 Tuckerm.), has a more or less exserted awn, thus differing from the T. monta- 

 num, Torr. (A. oreophila, Trin.), which is a dwarfed form, growing in tufts in 

 hollows of rocks, &c. 



