HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 251 

 149. Panicum sphaerocarpon Ell. 



Panicum sphaerocarpon Ell. Bot. S. C. & Ga. 1 : 125. 1816. "Grows in Georgia. Dr. 

 Baldwin." The type, in the Elliott Herbarium, consists of a single plant with a 

 mature, long-exserted panicle. The accompanying label reads: "Panicum sphaero- 

 carpon Hab. Georg. Dr. Baldwin." 



Panicum kalmii Swartz, Adnot. Bot. 6. 1829. "Hab. in America boreali (Pennsyl- 

 vania?): Prof. Kalm." The type, labeled "Panicum Kalmii Swartz in Adnot. Bot. 

 p. 6," in the Swartz Herbarium, is a single vernal plant. 



Panicum heterophyllum Swartz, Adnot. Bot. 6. 1829, not Spreng. 1822. This is 

 mentioned as a synonym of P. kalmii Swartz. 



Panicum dichotomum sphaerocarpum Wood, Class-book ed. 3. 786. 1861. Presum- 

 ably based on P. sphaerocarpon Ell., though the description hardly applies to this 

 species. 



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

 is described from a "specimen in New-Jersey lectum, n. 30." Doell's plant is evi- 

 dently one of the specimens distributed by Gray in Gramineae and Cyperaceae 1 : no. 

 30. 1834, under the above name. The specimen in the Gray Herbarium bears the 

 data "Hab -Pine barrens of New-Jersey." This was not described by Gray. It 

 represents the slender form of P. sphaerocarpon. 



Panicum microcarpum sphaerocarpon Vasey, Grasses U. S. 12. 1883. Based on 

 "P. sphaerocarpon, Ell." 



Panicum vicarium Fourn. Mex. PI. 2 : 20. 1886. Fournier cites only one specimen, 

 "Cordova (Schaffn. n. 285)." The type is in the Paris Herbarium. This name 

 was earlier listed by Hemsley a without description. 



DESCRIPTION. 



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

 spreading, occasionally nearly erect, the nodes appressed-pubescent; 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; ligules nearly or quite obsolete; blades thick and firm with usually incon- 

 spicuous nerves, ascending, 6 to 10 cm. long, 7 to 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 

 to 10 cm. long, nearly as wide, rather loosely 



• From flowered, the axis and ascending branches with 

 type specimen. . . , . , 



viscid spots; spikelets 1.6 to 1.8 mm. long, 1 to 1.3 



mm. wide (in exceptional specimens only 1.5 mm. long), obovoid-spherical at matu- 

 rity (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 to 1.5 mm. long, 1 to 1.2 mm. wide, obovoid-spherical. 



Autumnal form 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. 



Numerous specimens occur which are intermediate between this species and the 

 •following subspecies. These more slender plants with usually narrower blades and 

 slightly smaller spikelets are the form named Panicum nitidum var. crassifolium by 



a Biol. Centr. Amer. Bot. 3 : 498. 1885. 



