HITCHCOCK AND CHASE—_NORTH AMERICAN PANICUM. 323 
circa stagnum, 64 a Sav: versus Oquechee. Flor: Ma. 478.’ Elliott gives “‘P. 
dimidiatum, Walt. p. 72” as a synonym. 
Panicum waltert Muhl. Descr. Gram. 108. 1817, not Pursh, 1814. No locality nor 
specimen is cited, but after the description the author adds “P. dimidiatum Walter 
secundum Elliott.’? The specimen in the Muhlenberg Herbarium is labeled ‘‘ Pani- 
cum dimidiatum Walter, Ell. 478,’’ and is evidently a duplicate of Elliott’s specimen. 
Panicum hemitomon Schult. Mant. 2: 227. 1824. Based on Panicum waltert Muhl. 
Panicum carolinianum Spreng. Syst. Veg. 1: 310. 1825. Sprengel’s name appears 
to be based on P. walteri Ell. as he cites after the brief description, ‘‘ Carol. austr. (P. 
Walteri Ell.).”’ 
Panicum carinatum Torr. in Curtis, Bost. Journ. Nat. Hist. 1: 137. 1835, not 
Presl, 1830. ‘‘Hab. swamps,’’ [around Wilmington, N. C.]. Curtis’s specimen, 
labeled ‘‘Panicum carinatum n. sp. Tor. mss. North Carolina. Mr. M. A. Curtis,’’ is 
in the Torrey Herbarium. This is taken as the type since Torrey evidently intended 
this as a new species, although ‘‘P. Walteri Ell.’’ is cited as a synonym. 
Panicum digitarioides Carpenter; Curtis, Amer. Journ. Sci. II. 7: 410. 1849, not 
Rasp. 1833. This is mentioned as a synonym under P. carinatum Torr., Curtis 
doubtless taking the name from specimens distributed by Carpenter under this name. 
Such a specimen, collected by ‘‘W. M. Carpenter, prairie ponds, Opelousas & Attack- 
opay La.,”’ is in the Gray Herbarium. The species is later described by Steudel @ 
under this name, his description being a translation of that of Curtis. 
Panicum curtisti Chapm. Fl. South. U.S. 578. 1860, not Steud. 1854. This is pro- 
posed as a new name for ‘‘P. Walteri, HUl., not of Poiret nor Pursh. P. carinatum, Torr., 
in Curtis’s Plants, Wilmington, not oe eval ‘i 
Brachiaria digitarioides Nash, in Britton, Man. 77. 1901. Based on Panicum digi- 
tarioides Carpenter. 
‘ DESCRIPTION. 
Plants aquatic or semiaquatic, with extensively creeping rootstalks often producing 
numerous sterile shoots with overlapping, sometimes densely hirsute sheaths, and 
blades 10 to 25 cm. long and 8 to 12 mm. wide, strigose on one or both surfaces; fertile 
culms erect, 0.5 to 1.5 meters or more high, stout, usually hard, rarely rather soft and 
flaccid about the water line, glabrous; submerged sheaths rather loose and papery, 
often nodulose, aerial sheaths shorter than the internodes, close, glabrous or ciliate 
on the margin, rarely hirsute toward the summit like those 
of the sterile shoots, or the lower hirsute throughout; ligules 
lacerate-ciliate, about 1 mm. long; blades ascending or 
spreading, 10 to 25cm. long, 7 to 15 mm. wide, acuminate, 
rounded at base, firm, usually scabrous on the upper sur- 
face, smooth below; panicles short-exserted, 15 to 30 cm. 
long, very narrow, the branches erect or ascending, solitary 
or 2 or 3 in a fascicle, the lower distant, gradually approxi- 
mate upward, 2 to 10 cm. long, bearing short, appressed 
branchlets or subsessile spikelets along the triquetrous, 
Fig. 363.—P. hemitomon. scabrous rachis; spikelets 2.4 to 2.7 mm. long, 0.8 to 1 mm. 
| Hoe as heen aa : wide, lanceolate, acute, often slightly laterally compressed 
berg Herbarium. (that is the glumes so keeled that the spikelet lies on its 
side); first glume clasping, about half the length of spikelet, 
acute, 3-nerved; second glume strongly keeled, somewhat boat-shaped, acute, 3 to 5- 
nerved, slightly shorter than the 5-nerved sterile lemma, the latter inclosing a mem- 
branaceous, scabrous-nerved palea of nearly equal length; fruit 2.3 to 2.5mm. long, 0.7 
mm. wide, slightly boat-shaped, elliptic, acute, smooth and shining, not rigid, the mar- 
gins of the lemma inrolled toward the base only, the apex of the palea scarcely inclosed. 
In this species the spikelets rarely perfect their grains. P. hemitomon departs some- 
what from the typical ppacics of Panicum in that the fruit is less rigid and the tip of 
a Syn. Pl, Glum. 1: ; 75, 1854. 
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