138 



41. SPHEN6PHOLIS Scribn. 



Spikelets 2-3-flowered, the pedicels jointed just below the glumes ; rhachilla 

 prolonged behind the upper palea in a slender pedicel, articulated between the 

 florets, the glumes and lower floret with joint of pedicel tardily falling together ; 

 glumes subequal, exceeded by the uppermost floret, the first narrow, the second 

 much broader, usually obovate, becoming subcoriaceous in fruit, 3-nerved ; 

 lemma chartaceous, nerves obscure, awnless or awned below the summit, awn 

 usually straight or divergent ; palea hyaline, narrowed toward the base ; grain 

 inclosed within the rigid lemma, free. Slender perennials with usually flat 

 leaves and narrow terminal panicles. (Name from <r<f>-^v, a wedge, and #oX, a 

 scale, referring to the broadly obovate or wedge-shaped second glume.) EATONIA 

 Endlicher and later authors, not Raf. 



Spikelets awnless or with the second floret short-awned ; glumes dissimilar, the 



first linear, second obovate, becoming chartaceous. 

 Panicle narrow, densely flowered ; second glume as broad as long, subcucullate 



in fruit. . . ' 1. S. obtutata. 



Panicle lax, branches more or less spreading, at least in flower. 

 Glumes subequal, second broadly obovate, obtuse ; florets obtuse, the second 



very scabrous 2. S. nitida. 



Glumes" unequal, first shorter than the narrowly obovate second one; florets 



mostly acute, glabrous . . . . 3. S. palUns. 



Spikelets awned ; glumes similar. 



Lower floret usually awnless . 4. S. palustrig. 



Both florets awned (4) S. palustris, v.Jleaniosa. 



1. S. obtus&ta (Michx.) Scribn. Culms slender to rather stout, 3-10 dm. 

 high ; sheaths pubescent to nearly glabrous ; leaves 4-15 cm. long, glabrous ; panicle 



6-18 cm. long, often glomerate ; spikelets 2.5-3 mm. long ; 



glumes subequal, the second subcucullate, the broad chartaceous 



margins smooth and shining; lemmas similar or the second a 



little scabrous. Dry soil, Ct. to Fla., westw. to Mo. and Tex. 



June, July. FIG. 116. Var. PCBESCENS (Scribn. & Merr.) Scribn. 



Sheaths and sometimes culms and leaves pubescent. Ct. to 

 116 S obtnsata. ^ cn - an( * southw. Var. LOBATA (Trin.) Scribn. Sheaths and 

 Spikeletxa. leaves scabrous, not pubescent; panicle cylindrical, sometimes 



interrupted below ; spikelets densely crowded on the short oppressed 

 branches. Dry soil, and prairies, Me. to Fla., westw. throughout the U. S. ; 

 the commoner form in the North. 



'2. S. nitida (Spreng.) Scribn. Culms slender, 3-6 dm. high; sheaths pubes- 

 cent; leaves 3-6 cm. long, 2-5 mm. wide, pubescent; panicle 5-20 cm. long, 

 loosely flowered, widely spreading in flower, finally erect ; spikelets 3 mm. long, 

 cuneiform; glumes subequal, the broad second glume rounded or abruptly apic- 

 ulate ; lemmas oblong, obtuse, rarely short-awned just below the apex, second 

 lemma scabrous especially near the tip and keel. (Eatonia Dudley i Vasey.) 

 Woods, Vt. to Mich., and southw. May, June. Var. GLABKA (Nash) Scribn. 

 Sheaths and leaves glabrous. Va., and southw. . 



3. S. pAllens (Spreng.) Scribn. Culms 3-10 dm. high, usually slender; 

 sheaths usually glabrous, sometimes pubescent; leaves 5-20 cm. long, 4.6 mm. 

 wide, scabrous on the nerves, sometimes sparsely pilose above ; 

 panicles lax, nodding, 8-20 cm. long ; spikelets 3-4 mm. long, 

 oblong-lanceolate; glumes unequal, scabrous on the keels, the 

 first linear, ^-| as long as the broadly oblanctolate usually acute 

 second glume; lemmas lanceolate, acute, glabrous except on the 

 keel near the apex, the second projecting beyond the second 117 s al , eng 

 glume, sometimes awned below the apex. (Eatonia pennsylvanica <?pikeietx8 

 Gray.) Me. to N. C., w. to Wise., Kan., and Tex. In the 

 Mississippi Valley this species occurs on prairies, and has a denser panicle ; in 

 the Atlantic States, especially southward, it occurs in meadows and along 

 ditches, and has a more lax panicle. FIG. 117. Var. M.XJOR (Torr.) Scribn. 

 Panicles narrowly lanceolate or oblong, rather densely Jl<r> m/. the first glume 

 nearly equaling the rather narrow second one. (Eatonia intermedia Rydb.) 

 Nfd. to Wash., s. to 111., Col., and Ariz. 



