138 GRAMINEAE (GRASS FAMILY) 



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 a-^v, a wedge, and 0o\i's, 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. oUusata. 



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. 8. pattens. 



Spikelets awned ; glumes similar. 



Lower floret usually awnless 4. S.palustris. 



Both florets awned ' (4) S. palustris, v.flexuosa. 



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

 high ; sheaths pubqscent 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. PUBESCENS (Scribn. & Merr.) Scribn. 



Sheaths and sometimes culms and leaves pubescent. Ct. to 

 116 S obtusata Mich - and southw - Var - LOBATA (Trin.) Scribn. Sheaths and 

 Spik'elet x 3. ' leaves scabrous, not pubescent ; panicle cylindrical, sometimes 



interrupted below ; spikelets densely crowded on the short appressed 

 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 Dudleyi Vasey.) 

 Woods, Vt. to Mich., and southw. May, June. Var. GLABRA (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, ^-f as long as the broadly oblanceolate usually acute 

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

 keel near the apex, the second projecting beyond the second 

 glume, sometimes awned below the apex. (Eatonia pennsylvanica a- v 

 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\JOR (Torr.) Scribn. 

 Panicles narrowly lanceolate or oblong, rather densely flowered, the first glume 

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

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



