14 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
placed the species represented by the plate 298 under Panicum, and 
the other Tournefortian species of Milium under Holcus. But he 
has made one important alteration in the description, a comparison 
of which with the first edition shows the two to be identical except as 
to the statement concerning the calyx or glumes. In the first edition 
the diagnosis reads, ‘‘Gluma uniflora, trivalvis: Valvulis ovatis, acu- 
minatis, duabus interioribus oppositis, tertia a tergo alterius posita;”’ 
in the fifth, ‘‘Gluma uniflora, bivalvis: Valvulis ovatis, acuminatis.” 
By the change of trivalvis to bwalvis he has transferred the generic 
idea of Milium from Panicum miliaceum to Milium effusum. 
It is now necessary to decide upon the type species of Panicum as 
presented in the Species Plantarum. There is nothing in this work 
to indicate which species Linnzeus considered the type of the genus, 
but by taking into consideration the description of Panicum as given 
in the fifth edition of the Genera Plantarum we arrive at a partial 
interpretation of his ideas. In the latter work he describes the calyx 
(glumes and sterile lemma) and corolla (fertile lemma and palea) as 
follows: ‘‘Cal. Gluma uniflora, trivalvis: Valvulis ovato-acuminatis: 
tertia minima a tergo alterius posita. Cor. bivalvis: Valvulae ovato- 
acuminatae: altera minor planior.’”? The description of the other 
parts has no significance, but at the end is a note which throws much 
light on the question under consideration. It reads: ‘‘Obs. Aristae 
terminant in quibusdam corollae valvulam planiorem. Species datur 
involucro polyphyllo capillari instructa.”” It is evident from this 
note that Linneeus did not consider as typical those species with awns 
or with an involucre, though he admitted them as exceptional. As 
awned species he had in mind particularly Panicum crusgalli, an old 
and well-known species illustrated by Scheuchzer; and as mnvolucrate 
species he referred especially to his Panicum glaucum and P. ttalicum. 
In accordance with the recent American Code of Botanical Nomen- 
clature ¢ the type is chosen, in the absence of other indications, by an 
application of Canon 15, section d, which reads: ‘‘Where economic or 
indigenous species are included in the same genus with foreign species, 
the type is to be selected from (1) the economic species or (2) those 
indigenous from the standpomt of the author of the genus.”’ The 
only important economic species described by Linneus are Panicum 
americanum, P. rtalicum, and P. miliaceum, to which might be added, 
as of much less importance, P.dactylon. It seems evident then, that, 
since Linneeus did not consider as typical those species having an 
involucre, the type is the remaining important economic species, 
namely, Panicum miliaceum. 
It is unfortunate that Linneus and succeeding botanists did not 
retain Panicum and Milium for the groups containing the historic 
types; and especially unfortunate that Beauvois did not retain the 
@ Bull. Torrey Club 34; 172. 1907. 
