PANICUM AGROSTIDIFORME Lam. Ill. I: 172. 1791.
This name was given by its author to a grass from South America, probably from Cayenne, and its application to the plant so common in our region, the P. agrostokles Muhl., has never been satisfactory, not only because the description failed to fit our plant, but also on account of the remoteness of the region from which the Lamarckian plant originally came—a region the flora of which is tropical and not likely to contain among its members a grass native and plentiful in the eastern United States. A care ful comparison of a fuller description of this plant, in Encycl. Meth. (4: 748. 1797), with material from northern South Amer ica, where this grass was originally secured, leaves little doubt as to its proper identification. Among the characters given by Lamarck is that of the ciliate margins of the sheath fissure. There are three specimens in the herbarium of Columbia Univer sity which show this character in a marked degree, one of them from northern South America, another from Turk's Island, W. I., and the third from Truando Falls, on the Isthmus of Panama, col lected by Schott. These specimens agree with the description of
Lamarck, in the height and the jointed and leafy character of the culms, and in the size and form of the panicle, and the arrange ment of its spikelets. The culms arise from a creeping base, a character about which Lamarck says nothing, his specimens probably not exhibiting this feature. It differs from P. agrostoides Muhl. in the ciliate margins of the sheaths, in the shorter leaves, the smaller spikelets, and the creeping base of the stem. In P. agrostoides Muhl. the leaves are much elongated, the margins of the sheaths entirely naked, and the culms are caespitose, or at all events not creeping at the base.
The plants in the herbarium of Columbia University to which allusion is made, and which are referable to this species, are : I. F. Holton, La Paila, April 19, 1853, No. 91," sent out in his distribution of plants from " Neogranadina-Caucana." Graminaceae. Saxicolae. Ripariae. Truandofalls. Schott II. 858," and in red ink - No. 6." "Dr. Madiana, Turk's Island."