100 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



50. Panicum agrostoides Spreng. 



Panicum agrostoides Spreng. PI. Pugill. 2:4. 1815. Sprengel first gives an original 

 diagnosis, then cites "P. agrostidiforme Lam. ill. n. 895. encycl. 4. 738. Habitare 

 videtur in Cayenna. Misit etiam Miihlenbergius e Pensylvania." Then follows an 

 ample description which applies to the plant bearing the name Panicum agrostoides and 

 marked as sent by Muhlenberg which is found in the Willdenow Herbarium . Spren- 

 gel's herbarium is not segregated from the general herbarium at Berlin, as is Willde- 

 now's, and no specimen marked Panicum agrostoides from Muhlenberg was found in the 

 general herbarium. Sprengel's description was doubtless based on the specimen in 

 the Willdenow Herbarium, which is therefore taken as the type, the citation of La- 

 marck's name « as a synonym being erroneous. It would seem that the name P. agros- 

 toides was given by Muhlenberg on the specimen sent to Willdenow, since Muhlenberg 

 shortly after b published this as a new species of his own. c In the Muhlenberg Herbar- 

 ium specimens of both this species and of P. stipitatum are found in the cover marked 

 " Panicum agrostoides M." 



Panicum rigidulum Bosc; Spreng. Syst. Veg. 1 : 320. 1825. This is given as a 

 synonym of P. anceps Michx. and is based on P. "rigidulum Bosc. (W. herb.)." The 

 specimen in the Willdenow Herbarium is P. agrostoides. Pani- 

 cum rigidulum was described by Nees d as a new species with 

 Bosc as the author, and based on the specimen in the Willdenow 

 Herbarium. 



uigrostis polystachya Bosc; Steud. Nom. Bot. ed. 2. 1 : 40. 

 1840. This is given as a synonym of A. composita Poir. No 

 locality is cited. A specimen in the De Candolle Herbarium, 

 collected in Carolina by Bosc, is referable to P. agrostoides. In 

 Fig. 92.— p. agrostoides. the Delessert Herbarium are two specimens labeled by Bosc as 



From type specimen Aqrostis polystachya; one is Panicum anceps and the other is P. 



in Willdenow Herba- . 



rium> virgatum. 



Panicum elongatum ramosior[ius\ Mohr, Contr. Nat. Herb. 6 : 

 357. 1901. "Alabama: Damp cultivated ground. Mobile County, Pierce's Land- 

 ing." The type specimen, in the Mohr Herbarium, collected by "C. Mohr, Oct. 

 1885," is a portion of a plant with an unusually large and open panicle. 

 This species was described by Nash « under the name of P. agrostidiforme Lam. 



DESCRIPTION. 



Plants in dense clumps, from a short caudex, with numerous shoots of short leaves at 

 the base, erect, glabrous throughout except as noted, 50 cm. to 1 meter or more high; 

 culms rather stout, compressed; sheaths longer than the internodes, keeled, occasion- 

 ally pilose on the sides at the juncture with the blade; ligules erose, about 1 mm. long; 

 blades erect, conduplicate at the base, but flat above or sometimes drying involute, 

 20 to 50 cm. long, rarely longer, 5 to 12 mm. wide; panicles terminal and axillary, 

 finally long-exserted, 10 to 30 cm. long, rarely longer, usually half to two-thirds as wide 

 but occasionally diffuse and nearly as wide as long, the stiff branches ascending or 

 sometimes spreading at maturity, with moregr less divergent, densely flowered branch- 

 lets, commonly from the lower side, the ultimate branchlets and short pedicles 



a Panicum agrostidiforme Lam., the type of which is in the Lamarck Herbarium, is 

 P. laxum Swartz. 



&Descr. Gram. 119. 1817. 



c Sprengel does not include his P. agrostoides in the Systema [Syst. Veg. 1: 319. 

 1825] but gives P. agrostoides Muhl. as a synonym of P. proliferum. 



^Agrost. Bras. 163. 1829. 



«Britt. & Brown, Illust. Fl. 1 : 115./. 249. 1896. 



