268 NORTH AMERICAN FLORA [Volume 17 



Autumnal culms branching from the middle and upper nodes at the maturity of the 

 primary panicles, becoming widely spreading or decumbent at base, the early branches some- 

 times nearly equaling the primary culm, the ultimate branchlets in short, appressed fascicles, 

 the crowdeckblades usually equaling or exceeding the reduced panicles ; winter blades thickish, 

 lanceolate, often sparsely pilose or ciliate. 



Type locality: District of Columbia. 

 Distribution: Maine to Virginia. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 7: /. 60; Contr. U. S. Nat. Herb. 15: /. 267; 

 Britt. & Brown, 111. Fl. 3: App./. 267b; ed. 2./. 368. 



Panicum columbianum thinium Hitchc. & Chase; B. L. Robinson, Rhodora 10: 64. 1908. 



Panicum unciphyllum thinium Hitchc. & Chase; Hitchc. Rhodora 8: 209. 1906. Distinguished by 



its somewhat smaller spikelets, longer pubescence, more slender culms, and the autumnal phase 



with the branches aggregated toward the summit. Illustration: Contr. U.S. Nat. Herb. 15:/. 

 269. 



160. Panicum oricola Hitchc. & Chase; Hitchc. Rhodora 



8: 208. 1906. 



Vernal phase grayish, often purplish; culms densely tufted, 10-30 cm. high, spreading, 

 densely appressed- or ascending-pilose, the hairs on the nodes spreading; leaf -sheaths usually 

 mor.e than half the length of the internodes, appressed-pilose ; Hgule 1-1.5 mm. long; blades 

 firm, erect or ascending, 2-5 cm. long, 2-4 mm. wide, broadest near the base, acuminate, the 

 upper surface pilose with hairs 3—5 mm. long, the lower surface appressed-pubescent with 

 longer hairs intermixed; panicles short-exserted, or rarely long-exserted early in the season, 

 1:8-3 cm. long, rarely longer, about two thirds as wide, rather densely flowered, the axis ap- 

 pressed-pubescent, the flexuous branches ascending or spreading; spikelets 1.5 mm. long, 1 mm. 

 wide, broadly obovate, turgid, obtuse, pubescent with short spreading hairs; first glume one 

 third to half the length of the spikelet, abruptly pointed ; second glume and sterile lemma barely 

 equaling the fruit at maturity; fruit 1.3 mm. long, 0.9 mm. wide, broadly elliptic, very turgid. 



Autumnal phase prostrate, forming mats, with short, fascicled branches at all the nodes, 

 the branches appearing before the maturity of the primary panicles; leaves and panicles not 

 greatly reduced, the latter overtopped by the blades, which are less pilose than earlier ones; 

 winter blades sparsely pilose above. 



Type locality: Lewes, Delaware. 

 Distribution : Massachusetts to Virginia. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 271. 



161. Panicum sphaerocarpon Ell- Bot. S. C. & Ga. 1: 125. 1816. 



Panicum Kalmii Sw. Adnot. Bot. 6. 1829. 



Panicum heterophyllum Sw. Adnot. Bot. 6, as synonym. 1829. Not P. heterophyllum Spreng. 1822. 



Panicum dichotomum sphaerocarpum Wood, Class-Book ed. 1861. 786. 1861. 



Panicum nitidum crassifolium A. Gray; Doell, in Mart. Fl. Bras. 2 2 : 247. 1877. 



Panicum microcarpon sphaerocarpon Vasey, Grasses U. S. 12. 1883. 



Vernal plants light-green, in tufts of few to several culms, 20-55 cm. high, radiate-spread- 

 ing,occasionally nearly erect, the nodes appressed-pubescent ; leaf-sheaths nearly as long as or 

 longer than the comparatively short internodes, loose toward the summit, ciliate on the margin, 

 otherwise glabrous, sometimes with viscid tubercles between the nerves; ligule nearly or quite 

 wanting; blades thick and firm with usually inconspicuous nerves, ascending, 6-10 cm. long, 

 7-14 mm. wide (rarely longer or wider), the upper and lower smaller, acuminate, slightly 

 narrowed to the subcordate base, rough on the upper surface, smooth below, the cartilaginous, 

 scabrous margins stiffly ciliate toward the base; panicles long-exserted, 5-10 cm. long, nearly 

 as wide, rather loosely flowered, the axis and ascending branches with viscid spots; spikelets 

 1.6-1.8 mm. long, 1-1.3 mm. wide (in exceptional specimens only 1.5 mm. long), obovoid- 

 spheric at maturity (oval when young), puberulent; first glume about one fourth the length of 

 the spikelet, obtuse; second glume and sterile lemma equaling the fruit at maturity; fruit, 

 1.4—1.5 mm. long, 1-1.2 mm. wide, obovoid-spheric. 



Autumnal phase prostrate-spreading, sparingly branching late in the season from the 

 base or lower and middle nodes, the branches short, mostly simple, the blades and panicles 

 not greatly reduced; winter rosettes of many thick, ovate or ovate-lanceolate, white-margined 

 leaves, appearing early. 



