HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 11 



HISTORY AND LIMITATION OF THE GENUS. 

 f PRE-LINN^AN USE OF THE NAME. 



The name Panicum, as used by the ancient Latin authors, referred 

 to Chaetochloa italica (L.) Scribn. (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 a 

 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.) Scribn., C. viridis (L.) 

 Scribn., C. verticillata (L.) Scribn., Pennisetum americanum (L.) 

 Schum., Echinocliloa crusgalli (L.) Beauv., Polypogon monspeliensis 

 (L.) Desf., and Gastridium lendigerum (L.) Gaud. The species fig- 

 ured, however, is a form of ChaetocJiloa 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. 



Linnaeus b 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 c figures cited by Linnaeus are 

 those of the spikelets of CJiaetocliloa viridis and EchinocMoa crusgalli. 

 Linnaeus' s description states that the involucre is many-leaved and 

 capillary O'lnvolucrum 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 CJiaetocliloa viridis (L.) Scribn. 

 as the species considered by Linnaeus 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 Echinocliloa 

 crusgalli. Linnaeus 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 d 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- 



alnst. Rei Herb. 1: 515. pi. 298. f. M. 1700. cAgrost.45. pi. 2.f. 2. 1719. 

 &Gen. PI. 17. 1737. <*Gen. PL 29. 1754. 



