HITCHCOCK AND CHASE—NORTH AMERICAN PANICUM. 11 
HISTORY AND LIMITATION OF THE GENUS. 
PRE-LINNZAN USE OF THE NAME. 
The name Panicum, as used by the ancient Latin authors, referred 
to Chaetochloa italica (L.) Seribn. (Panicum italicum L.), and the 
genus Panicum of the medieval botanists was based mainly upon this 
species, which was commonly cultivated as a cereal. Tournefort ¢ 
gave the genus a more formal standing and described fifteen species, 
one of which he figured. By him the genus is characterized as 
having the flowers aggregated in a spike and is made to include spe- 
cies now referred to Chaetochloa italica (L.) Seribn., C. viridis (L.) 
Seribn., C. verticillata (L.) Secribn., Pennisetum americanum (L.) 
Schum., Echinochloa crusgalli (L.) Beauv., Polypogon monspeliensis 
(L.) Desf., and Gastridium lendigerum (L.) Gaud. The species fig- 
ured, however, is a form of Chaetochloa italica, which is, therefore, 
the type of Panicum as limited by Tournefort. 
On the other hand the ancient name Milium referred to Panicum 
miliaceum L., the common millet of Europe. Tournefort followed 
his predecessors in including under the genus Milium the millets (Pa- 
nicum miliaceum L.) and the sorghums (Holcus sorghum L. ), but 
figures the former. 
Linnzus ® at first recognized the two genera Panicum and Milium, 
basing the former on ‘“‘Panicea Scheuch. 2:2,’ and the latter on 
“ Tournef. 298.” The Scheuchzer® figures cited by Linneus are 
those of the spikelets of Chaetochloa viridis and Echinochloa crusgalli. 
Linneus’s description states that the involucre is many-leaved and 
capillary (‘‘Involucrum uniflorum, polyphyllum: foliolis capillari- 
bus, inaequalis insertionis”’), which refers to the genus Chaetochloa 
Scribn. (Setaria Beauv.). This description, together with his ref- 
erence to Scheuchzer, would indicate Chaetochloa viridis (.) Scribn. 
as the species considered by Linnzus as typical of his genus Pani- 
cum. He also adds a note that in some species the valve of the 
corolla terminates in an awn, which statement refers to Echinochloa 
crusgalli. ULinneus here uses the name Milium in the same sense as 
does Tournefort. The two genera are treated in the same manner in 
the succeeding editions of the Genera Plantarum, up to and including 
the fourth, published in 1752, except that a statement is added to 
the effect that an involucre is wanting in some species. In the fifth 
edition of this work ¢ the reference to Scheuchzer is omitted, as is also 
that portion of the diagnosis which refers to the involucre, and the 
above-mentioned note is replaced by one to the effect that species 
are included in which there is a many-leaved, capillary involucre. 
That is, in the first edition of this work that was published after the 
Species Plantarum the genus Panicum was based upon species hav- 
aInst. Rei Herb. 1: 515. pl. 298.f. M.1700. © Agrost. 45. pl. 2. f. 2. 1719. 
b Gen. Pl. 17. 1737. 4 Gen. Pl. 29. 1754. 
