GEA.MISEAE QGRASS FAMILY) 



lay 



'^ 4. S. paliistris (Michx.) Scribn. Gulma 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 mm. long ; glumes similar, lanceolate, acute, subequal ; 

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

 less, rarely short-awned ; 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 pennsylvanicd 

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

 soutbw. Var. PLExn6sA Scribn. Culms 4-6 dm. high ; panicles 

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

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

 awned. — Del. {Commons), Pa. (Heller). Fig. 118. 



118. 8. pal., V. flex. 

 Spikelet X 3. 



42. KOELERIA Pers. 



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

 upper palea ; glumes unequal, slightly shorter than the florets, membranaceous, 

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

 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 Frof. &. L. Koeler, an early writer 

 on grasses.) , 



1. K. crist^ta (L.) Pers. Culms «rect, 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 ; 

 spikelets 4-5 mm. long ; the glumes and lemmas scabrous. — Dry soil, Ont. and 

 0. to B. C, and southw. ; introduced in N. E. (Eurasia.) — Very variable. 

 Fig. 119. 



TRISETUM 



119. K.cristata x2%. 

 Spikelet. Lower part 



of lemma spread 



open. 



43. 



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 

 tres, 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 5-6 mm. long ; 

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

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

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

 Beauv. and var. moUe Gray.) — Mts. and rocky banks, Lab. 

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

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



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

 sheaths and blades roughish ; panicie shining, lax, nodding, 

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

 minutely scabrous, bluntly 2-toothed at the apex, awn 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. ma), x 2. and Vt. Var. mXjus (Gray) Hitchc. Lower sheaths 

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



120. T. spicatum x 3 

 Spikelet and floret. 



