HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 233 

 137. Panicum villosissimum Nash. 



Panicum tectum Wjlld. ; Spreng. Syst. Veg. 1 : 313. 1825. This is given as a synonym 

 under P. dichotomum. The type specimen, in the Willdenow Herbarium, is the 

 autumnal form. It is labeled "Panicum tectum panicula divaricata. * * * 

 Hab. a America boreali. ' ' A second specimen so named in the Willdenow Herbarium, 

 was sent by Muhlenberg and is P. xalapense. 



Panicum dichotomum villosum Vasey, U. S. Dept. Agr. Div. Bot. Bull. 8 : 31. 1889, 

 not P. villosum Ell. 1816. The author cites "P. villosum Ell.?" but since on the same 

 page he gives this name unquestioned as a synonym of P. consanguineum Kunth, 

 Elliott's species can not be taken as the basis of Vasey's variety. No locality nor speci- 

 men is cited. A freely branching early autumnal specimen in the National Herbarium 

 marked "dichotomum var. villosum" in Vasey's writing, and agreeing well with his 

 description, is chosen as the type. This was collected "near Pierce's Mill, Rock 

 Creek, D. C, July 1, 1883," byDr. Vasey. 



Panicum nitidum pubescens Scribn. in Kearney, Bull. Torrey Club 20: 479. 1893. 

 This is listed without description as the name of two numbers, 58 and 141, of Kearney's 

 collection of plants in Harlan and Bell Counties, Kentucky. " Panicum laxijlorum 

 pubescens Chapm." is cited but as the latter name had not at that time been published 

 by Chapman, P. nitidum pubescens must be considered a nomen nudum. The speci- 

 mens of his 58 and 141 in the National Herbarium, and distributed by Kearney, com- 

 prise P. villosissimum and P. huachucae, but the majority are the former. 



Panicum laxijlorum pubescens Chapm.; Kearney, Bull. Torrey Club 20: 479. 1893, 

 not Vasey 1892. This is given as a synonym of P. nitidum pubescens Scribn., but is later 

 described by Chapman « and based on P. pubescens Lam. 



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

 John K. Small in the Ocmulgee River swamp, below Macon [Georgia], May 18-24, 

 1895." The type, in Nash's herbarium, consists of several vernal culms with branches 

 appearing, but secondary panicles not expanded. The spikelets are 2.3 mm. long. 



Panicum atlanticum Nash, Bull. Torrey Club 24:346.1897. "Type specimens 

 collected by the writer on dry somewhat shaded knolls in the grounds of the New York 

 Botanical Garden." The type, in Nash's herbarium, consists of a small clump and of 

 two single specimens, the culms beginning to branch, primary panicles mature, sec- 

 ondary panicles immature. The spikelets are 2.2 mm. long. This differs from the 

 type of P. villosissimum only in the somewhat stiffer culms and slightly smaller 

 spikelets. 



Panicum haemacarpon Ashe, Journ. Elisha Mitchell Soc. 15: 55. 1898. "District 

 of Columbia: Kearney; 1897. Ashe: North Carolina; Chapel Hill, 1898. Iowa: 

 Carver; Jewell Junction, 1895, No. 258." The first specimen cited is chosen as the 

 type. This is in Ashe's herbarium and consists of a tuft of three simple culms with 

 nearly mature panicles and two autumnal culms of the previous year. 



Panicum xanthospermum Scribn. & Mohr, Contr. Nat. Herb. 6 : 348. 1901. "Type 

 specimen collected by Dr. Charles Mohr in open sandy soil, Greenville, Butler County, 

 Ala., May 8, 1898." This specimen, which is in the National Herbarium, consists of a 

 tuft with two simple culms 18 and 20 cm. high, and the burned bases of others, evi- 

 dently a second growth after a fire. Except in its smaller size it compares well with 

 the type of P. atlanticum. The spikelets, which are immature, are 2.2 mm. long. 

 By selecting the shorter culms it could be matched from many typical clumps of P. 

 villosissimum. 



This species was described by Seribner& as Panicum pubescens Lam., as indicated 

 by a note upon a sheet, then in his possession, of a duplicate type of P. villosissimum. 



«F1. South. U. S. ed. 3. 586. 1897. 



&Tenn. Agr. Exp. Sta. Bull. 7 : 52. pi. 15. f. 58. 1894. 



