GRAMINEAE (GRASS FAMILY) 



123 



80. O. aspt-rifolta 



*l%. 



Spikelet (below). 

 Floret (above). 



e B 



* * Spikelets, excluding awn, 6-9 mm. long. 



2. 0. asperif&lia Michx. Culms tufted, 2-7 dm. high, erect or geniculate at 

 the lowest node ; sheaths usually crowded at the base ; blades erect, scabrous 

 especially on the glaucous lower surface, those of the base 

 often exceeding the culm, 5-8 mm. wide, flat or involute on 

 the margins, attenuate ; culm-leaves usually less than 1 cm. 

 long; panicle contracted, 6-12 cm. long, the branches simple, 

 erect ; spikelets, excluding awn, 6-8 mm. long ; glumes subequal, 

 short-oil iate at the apiculate summit ; lemma nearly or quite as 

 long as the second glume, sparingly pubescent ; awn 6-10 mm. 

 long ; lodicules $ the length of the palea. 

 Wooded hillsides, along waterways, etc., Nfd. 

 to B. C., s. to Pa., Minn., and N. Mex. June. 

 FIG. 80. 



3. 0. racembsa (Sm.) Ricker. Culms tufted, 

 erect, 3-12 dm. high, leafy to the summit; leaves 

 1-3.5 dm. long, 4-15 mm. wide, flat, narrowed 



f toward the base, taper-pointed, scabrous below, 



pubescent above ; panicle 7-25 cm. long, branches 

 nearly simple, usually ascending ; spikelet, excluding awn, 7-9 mm. 

 long ; glumes equal, acute ; lemma somewhat shorter, pubescent, 

 becoming black in fruit; awn 1.5-2.5 cm. long; lodicules minute. 

 (Milium Sm. ; O. melanocarpa Muhl.) Rocky woods, Me. to 

 Ont., southw. to Del. and la. June-Oct. FIG. 81. 



24. STIPA L. FEATHER GRASS 



Spikelets 1-flowered, in terminal panicles ; glumes narrow, acute or bristle- 

 tipped ; floret with a bearded usually sharp-pointed callus ; lemma convolute, 

 indurated, including the small palea and perfect flower, terminating in a simple 

 strong persistent geniculate twisted awn ; grain cylindrical, tightly included 

 in the indurated fruiting lemma. Rather large tufted perennials with involute 

 leaves. (Name from ffrinri), tow, in allusion to the flaxen appearance of the 

 feathery awns of the original species.) 



* Glumes 4-12 mm. long. 

 - Callus blunt ; awn 1 cm. or less long. 



1. S. canadSnsis Poir. Culms tufted, 3-6 dm. high ; leaves 4-12 cm. long, 

 narrow, involute, scabrous; panicle loose, 5-12 cm. long, the opposite few- 

 flowered branches ascending ; glumes subequal, oblong, subacute, 4 mm. long, 

 slightly exceeding the pubescent oblong lemma; awn 6-10 mm. long. (<V. 

 Sichardsoni Man. ed. 6, not Link ; S. Macounii Scribn. ) Woods and thickets, 

 N. B., Me., N. H., N. Y., n. shore of L. Superior, Sask., and northw. 



*- +- Callus acute; awn more than 1.5 cm long. 



2. S. viridula Trin. Culms clustered, 5-10 dm. high, 

 sparingly branched ; basal sheaths overlapping, the long 

 usually scabrous involute or sub-involute blades elongated, 

 upper blades shorter, mostly setaceous ; panicle narrow, 

 erect, 1-2 dm. long, the branches mostly in pairs, erect, 

 rather densely flowered from near the base ; glumes 7-9 mm. 

 long, acuminate-setaceous, exceeding the pale oppressed- 

 pubescent lemma ; awn 2-4 cm. long ; callus usually rather 

 short. Prairies and meadows, w. Minn., the Dakotas, and 

 southwestw. July, Aug. Variable. 



3. S. avenacea L. (BLACK OAT GRASS.) Culms tufted, 

 slender, erect or ascending, 3-10 dm. high, leafy at the base ; 

 sheaths shorter than the internodes ; blades 1-1.5 mm. wide, 

 usually involute, the basal ones J-i the length of the culms, 



82. S. avenacea x 1%. 

 Flower and glumes. 



