GRAMINEAE ((JKASS FAMILY) 



139 



4. S. palustris (Michx.) Scribn. Culms 6-10 dm. high; sheaths and leaves 

 glabrous, or lower sheaths sometimes pubescent ; leaves 8-12 cm. long, 3-6 mm. 

 wide, scabrous ; panicles 10-20 cm. long, narrow ; spikelets 

 6-7 min. long ; glumes similar, lanceolate, acute, subequal ; 

 lemmas lanceolate, the first acute or acuminate-pointed, awn- 

 less, rarely short-owned ; the second bearing a slender divergent 

 awn below the acute or 2-toothed apex ; awn 4-5 mm. long. 

 ( Trisetum pennsylvanicum Man. ed. 6, not Avena pennsylvanica 

 L. ; T. palustra Trin.) Low grounds, Mass, to 111. and 

 southw. Var. FLExu6sx Scribn. Culms 4-6 dm. high ; panicles 

 8-12 dm. long, open, the flexuous branches widely spreading at 

 least in flower; spikelets 4-5 mm. long, the first floret usually 

 awned. Del. (Commons'), Pa. (Heller'). FIG. 118. 



118. 8. pal., v. flei. 

 Spikelet x 3. 



42. KOELERIA Pers. 



Spikelets 

 upper palea ; 



119. K. cristata 

 Spikelet. Low 



of lemma i 



open. 



spikelets 4-5 

 (). to B. C. 

 FIG. 119. 



sr part 

 spread 



2-4-flowered ; rhachilla prolonged into a naked pedicel behind the 

 glumes unequal, slightly shorter than the florets, membranaceous, 

 acute, the first 1-nerved, the second 3-nerved ; lemma char- 

 taceous-membranaceous, the margins scarious, faintly 3-5- 

 nerved, acute or mucronate ; palea hyaline ; grain loosely 

 inclosed within the subrigid lemma, free. Tufted perennials 

 with narrow leaves and densely flowered terminal spike-like 

 panicles. (Named for Prof. G. L. Koeler, an early writer 

 on grasses.) 



1. K. cristata (L.) Pers. Culms erect, 3-6 dm. high, 

 leafy at the base ; sheaths retrorsely pubescent, at least the 

 lower ; blades flat or becoming involute ; panicle cylindrical, 

 4-15 cm. long, often interrupted at base, pale and shining ; 



mm. long; the glumes and lemmas scabrous. Dry soil, Ont. and 

 and southw. ; introduced in N. E. (Eurasia.) Very variable. 



43. TRISETUM Pers. 



Spikelets 2(rarely 3-5) -flowered, rhachilla prolonged behind the upper palea 

 as a hairy bristle or pedicel ; glumes unequal, the second 

 about as long as the florets, keeled ; lemma membranaceous, 

 keeled, 2-toothed at the apex, bearing a slender dorsal awn ; 

 palea narrow, 2-toothed ; grain smooth, inclosed in the lemma 

 and palea but free from them. Tufted perennials with nar- 

 row or spike-like or loose terminal panicles. (Name from 

 t res, three, and seta, a bristle. ) 



1. T. spicatum (L.) Richter. Culms slender, erect, 1.5-6 

 dm. high ; sheaths and blades more or less puberulent, blades 

 2-10 cm. long, 1-3 mm. wide ; panicle shining, spike-like, 3-12 

 cm. long, often interrupted below ; spikelets 6-6 mm. long ; 

 the second glume broader than the first, 3-nerved ; lemma 

 minutely scabrous, the awn inserted about \ below the acumi- 

 nate-toothed apex, 4-5 mm. long, divergent. ( T. subspicatum 

 Beauv. and var. molle Gray.) Mts. and rocky banks, Lab. 12 - T - sputum x8. 

 to Alaska, s. to Ct., N. Y., the Great Lakes; and along the Spikelet and floret, 

 mts. toN. C. (Eurasia.) FIG. 120. 



2. T. melicoides (Michx.) Vasey. Culm 3-8 dm. high ; 

 sheaths and blades rough ish ; panicle shining, lax, noiUitnj. 

 10-12 cm. long; spikelets 7 mm. long ; callus hairy ; lemma 

 minutely scabrous, bluntly ^-toothed at the apex, aicn 1-2 

 mm. long, straight, erect. (Graphephorum Desv. ) Gulf 

 of St. Lawrence to the Great Lakes, s. to N. B., Me., 

 121. T. mel., v. maj. x 2. and Vt. Var. H\JUS (Gray) Hitchc. Lower sheaths 

 Spikelet and floret. pubescent ; upper surface of the leaves pilose ; lemmas 



