152 



CONTKIBUTIONS FROM THE NATIONAL HEBBARIUM. 



could not be found in the Trinius Herbarium. Since Sprengel cites "P. acuminatum 

 Muhl." under his P. muhlenbergii his specimen or a part of it is doubtless the specimen 

 referred to by Trinius. The description well applies to an involute-leaved plant of 

 P. depauperatum. 



Panicum sprengelii Kunth, Rev. Gram. 1 : 39. 1829. Based on P. muhlenbergii 

 Spreng., without explanation as to change of name. 



Panicum depauperatum involutum Wood, Class-book 786. 1861. Based on P. 

 involutum Torr. 



f Panicum depauperatum laxa[um] Vasey, U. S. Dept. Agr. Div. Bot. Bull. 8: 29. 

 1889. "Virginia, Florida, Texas, Arkansas, Missouri." Described as "weaker 

 stemmed, panicle with longer and more spreading branches, * *■ * spikelets 

 smaller." No type is indicated and there is no specimen in the National Herbarium 

 80 marked by Doctor Vasey. The description would seem to apply to P. linearifo- 

 lium, but the range given is south of that in which that species is common, and no 

 specimens of it from any of the States mentioned, except one each from Missouri, 

 Arkansas, and Texas which are labeled "Panicum depauperatum Muhl." in Vasey's 

 writing, were in the National Herbarium in the time of Doctor Vasey. Hitchcock's 

 no. 1354, Stone Mountain, Georgia, with spikelets 3.1 to 3.2 mm. long, and rather 

 loose panicles may represent Vasey's variety. 



DESCRIPTION. 



Vernal form with culms several to many in a tuft, 20 to 40 cm. high, slender but rather 

 stiff, erect or spreading at the summit, glabrous, puberulent or sometimes pilose; 

 nodes ascending-pubescent; sheaths, except the lowest, shorter than the internodes, 

 glabrous to papillose-pilose; blades linear, 6 to 15 cm. long, 2 to 5 mm. wide (the lower 

 shorter), often involute in drying, scabrous on both surfaces, sometimes pubescent 

 beneath; panicles exserted, usually not much exceeding the leaves, 4 to 8 cm. long, 

 rarely longer, few-flowered, the rather strict, remote branches narrowly ascending at 

 maturity; spikelets 3.2 to 3.8 mm. long, rarely only 3 mm. eras much as 4 mm. long, 

 1.5 to 1.7 mm. wide, elliptical, pointed, glabrous or sparsely pubescent; first glume 

 one-third to half the length of the spikelet, subacute; second glume and sterile lemma 



equal, extending beyond the fruit, 

 forming a beak, strongly 7 to 9-nerved; 

 fruit 2.1 to 2.3 mm. long, 1.4 to 1.5 mm. 

 wide, oval, minutely umbonate at the 

 apex. 



Autumnal form similar to the ver- 

 nal, the reduced secondary panicles 

 produced on branches from the basal 

 or lower nodes, more or less concealed 

 in the tuft of basal leaves. 



This species is variable as to pubes- 

 cence and size of spikelets. The 

 spikelets of the type specimen are 3.5 

 mm. long, those of the glabrous plants 

 on the same sheet in the Muhlenberg Herbarium are 3.9 mm. long. Many New Eng- 

 land specimens and occasional specimens from elsewhere have spikelets only 3 mm. 

 long. This form is represented by Chamberlain 298, Chase 3379, and Parlin 1957 from 

 Maine; Burgess in 1893 from Massachusetts; Pierron in 1876 from Pennsylvania, and 

 Lansing 2743 from Indiana. The difference in length is often due to the inrolling of 

 the summit of the second glume and sterile lemma, but the glumes show greater pro- 

 portion of variation than usual in this genus. As a rule the spikelets do not vary on 

 the same plant, but Chase 2402, has spikelets 3 mm. long on the terminal panicle and 

 3.5 to 4 mm. long on the basal panicles. The fruit shows little variation in size. 



Fkj. 136.— P, depauperatum, From type specimen. 



