260 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



more pubeBcent spikelets, the thicker, involute-pointed blades and the large basal 

 rosette of firm leaves. In Hitchcock 1438, from Wilmington, N. C, referred here, 

 the pubescence is so copious as to sug- 

 gest P. leucothrix, but the nearly obso- 

 lete ligule and the size of the spikelets 

 place it, though somewhat doubtfully, 

 in P. tenue. Hitchcock's no. 1467 is an 

 unusually robust specimen with pani- 

 cles as much as 9 cm. long. 



DISTRIBUTION. 



Moist sandy woods, eastern North 

 Carolina and northern Florida. 



North Carolina: Parmele, Ashe 

 in 1899; Manteo, Ashe in 1898; 



Wards Mill, Chase 3170, 3172, 3183; WUmington, Ashe in 1899, Hitchcock 332, 

 1467. 

 Florida: Lake City, Bitting 20. 



^ 153. Panicum albomarginatum Nash. 



Panicum albomarginatum Nash, Bull. Torrey Club 24: 40. 1897. "Collected by 

 the writer in low pine land at Eustis, Lake County, Florida, early in June, 1894, 

 no. 925." The type, in Nash's herbarium, consists of two large tufts in the early 

 branching state, the culms 15 to 28 cm. high, the primary panicles devoid of spikelets. 



Fig. 282.— Distribution of P. tenue. 



Trx. 



description. 



Vernal plants usually grayish green, often purplish; culms densely tufted, 15 to 

 40 cm. high (rarely taller), slender but firm, ascending or spreading, glabrous includ- 

 ing the nodes; leaves crowded at the base, distant above, sheaths sometimes pubescent 

 on the margin and at the summit, otherwise glabrous, or the lowermost sometimes 

 obscurely pubescent; ligules 0.3 mm. long, dense; blade§^rm, those of the midculm 

 4 to 6 cm. long, 4 to 6 mm. wide, rounded at the ba8e,( ^ick an^ ^r^'"wrtbrarprominenF 

 white, finely serrulate, cartilaginous margin, ascending or spreading, glabrous, the 

 crowded basal blades as much as 11 cm. long, and the uppermost blade usually much 

 reduced; panicles finally long-exserted, 3 to 6 cm. long, nearly 

 as wide, rather densely flowered, the flexuous branches 

 ascending or spreading; spikelets 1.4 to 1.5 mm. long, 0.7 

 mm. wide, obovate-elliptic, subobtuse, turgid at maturity, 

 densely puberulent; first glume one-fifth to one-fourth as 

 long as the spikelet, obtuse or subacute; second glume and 

 sterile lemma scarcely equaling the fruit at maturity; fruit 

 1.25 mm. long, 0.65 mm. wide, elliptic, subacute. 



Autumnal form spreading, the primary culms branching 

 from the base and lower nodes, these early branches much 

 longer than the primary internodes and repeatedly branching, forming bushy tufts, the 

 ultimate branchlets and reduced blades appressed ; winter blades stifHy erect or spread- 

 ing, very smooth and firm. 



This species is distinguished by the long crowded basal and distant upper blades, 

 the uppermost usually less than half as long as those of the midculm; and by the 

 autumnal form in which the primary culms branch from the basal and lower, never 

 from the upper, nodes. 



The specimens collected by Hitchcock in Cuba (no. 555) are robust plants and 

 differ from typical P. albomarginatum in having a ligule 1 mm. long. 



Fig. 283. — P. albom,arginw 

 turn. From type speci' 

 men. 



