276 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



166. Panicum webberianum Nash. 



Panicum webberianum Nash, Bull. Torrey Club 23: 149. 1896. "Collected by 

 the writer on the edge of a clay pit in the low pine land at Eustis, Lake Co., Florida, 

 May 16-31, 1894, No. 781." The type, in Nash's herbarium, consists of two small 

 tufts of vernal culms 35 to 45 cm. high, with blades as much as 1 cm. wide, and mature 

 primary panicles, the spikelets 2.5 mm. long. 



Panicum onsloivense Ashe, Journ. Elisha Mitchell Soc. 16: 88. 1900. "Type 

 material was collected near Ward's Mill," Onslow County, N. C. The type, in Ashe's 

 herbarium, is the vernal form with immature panicles, the culms glabrous or minutely 

 puberulent, the lower blades as much as 1 cm. wide, the immature spikelets 2.4 mm. 

 long. Other specimens in Ashe's herbarium and some distributed as P. onslowense 

 and bearing the same data as the type are P. lancearium. 



DESCRIPTION. 



Vernal form commonly purplish; culms few to several in a tuft, rather stout, erect 

 or ascending, 20 to 50 cm. high, minutely puberulent or glabrous; leaves somewhat 

 crowded below, distant above; sheaths minutely puberulent at the summit, often 

 ciliate on the margin, otherwise glabrous or nearly so; blades firm, ascending, espe- 

 cially the lower somewhat incurved or spoon-shaped, 3 to 9 cm. long, 4 to 12 mm. wide, 

 usually ciliate at base and sometimes along the margin, rounded or subcordate at base, 

 acute but not long-acuminate; panicles finally long-exserted, 4 to 10 cm. long, two- 

 thirds as wide, the numerous flexuous branches spreading or the lower even reflexed, 

 the branchlets and pedicels usually rather short, thus giving to the main branches a 

 somewhat racemose appearance; spikelets 2.3 to 2.5 mm. long (in exceptional speci- 

 mens only 2.1 to 2.2 mm. long), 1.2 to 1.3 mm. 

 wide, obovoid to pyriform, commonly green, 

 conspicuously purple-stained at the base; first 

 glume one-third to two-fifths as long as the 

 spikelet; second glume and sterile lemma mi- 

 nutely pubescent or glabrous, the glume slightly 

 shorter than the fruit and sterile lemma; fruit 

 1.9 to 2 mm. long, 1.2 mm. wide, elliptic, under 

 a lens minutely papillose-roughened, puberu- 

 lent at the tip. 



Autumnal form spreading or decumbent, 

 flab ellately branching at the middle and upper 

 nodes, the branches appressed and rather evenly distributed, sometimes somewhat 

 fascicled; winter blades 3 to 8 cm. long, 5 to 10 mm. wide, strongly stained with 

 purple, forming a flat rosette. 



As a whole this species is readily distinguished from P. lancearium by its stouter, 

 taller culms, much larger blades, and in typical specimens by the larger spikelets, but 

 a few specimens occur in which only the lower blades are much larger than in P. lan- 

 cearium, and rather numerous specimens in which the spikelets are only 2.1 to 2.2 mm. 

 long. The minutely papillose-roughened fruit proves constant for all the specimens 

 here referred to P. webberianum, but this character is evident only under a strong lens. 



-P. webberianum. 

 specimen. 



From tj^pe 



DISTRIBUTION. 



Low pine land, North Carolina to Florida. 

 North Carolina: Onslow County, Ashe in 1899; Wilmington, Chase 4569^, 

 Hitchcock 1433, 1472. 



