1916] Hubbard, — Notes on Gramineae, — I 231 



NOTES ON GRAMINEAE, — I. 



F. Tracy Hubbard. 



In the past two years' study certain necessary changes in the nomen- 

 clature of the Gramineae of the seventh edition of Gray's Manual 

 have been noted and furthermore in collections which have been 

 examined certain additions to the Manual have appeared. With a 

 view to calling these facts to the attention of the Manual users this 

 paper has been prepared. 



Holcus halepensis L. Sp. PI. 2: 1047 (1753). Sorghum halepense 

 (L.) Pers. Syn. 1: 101 (1805); Hitchc. in Gray Man. ed. 7, 95 (1908). 

 Andropogon halepensis (L.) Brot. Fl. Lusit. 1: 89 (1806). — As pointed 

 out by Hitchcock in Jepson Fl. Calif. 126 (1912) Holcus L. should be 

 used for the species which recent authors have called Sorghum rather 

 than those for which they have retained the name. While not accept- 

 ing the type-species reason as a basis for this change, I have reached 

 the same conclusion by studying the description of Holcus as given 

 by Linnaeus Gen. PI. ed. 5 469 (1754) which I believe applies to 

 II. Sorghum and its allies and really excludes //. lanatus and its allies. 

 This conclusion is strengthened by Linnaeus's generic synonym, Sorg- 

 hum, Mich. 



Digitaria Ischaemum Schreb. ex Muhl. Descr. Gram. 131 (1817). 

 Panicum lineare Krock. Fl. Siles. 1:95 (1787) non L. P. Ischaemum 

 Schreb. ex Schweigg. Spec. Fl. Erlang. 16 (1804). D. humifusa Pers. 

 Syn. 1: 85 (1805) ; Hitchc. in Gray Man. ed. 7, 95 (1908). P. glabrum 

 Gaud. Agrost. Helv. 1:22 (1811). D. glabra (Gaud.) Beauv. Agrost. 

 51, 169 (1812). D. linearis (Krock.) Rostaf. in Verb. Zool.-Bot. 

 Ges. Wien. 22: 99 (1872) non Pers. Syntherisma linearis (Krock.) Nash 

 in Bull. Torr. Bot. CI. 22:420 (1895). S. humifusum (Pers.) Rydb. 

 in Mem. X. Y. Bot. Gard. 1:469 (1900). S. Ischaemum (Schreb.) 

 Nash in No. Am. Fl. 17: 151 (1912). 



Although there is no specimen of D. Ischaemum in the Muhlenberg 

 herbarium [according to the list of grasses given by Scribner and 

 Merrill in Circ. U. S. Div. Agrost. 27 (1900)] there seems little question 

 of the identity of his species. In the first place Muhlenberg cites 

 Schreber as the authority of his plant and Schreber was a friend of his 

 so that he was probably in correspondence with him and probably 

 D. Ischaemum is based on Panicum Ischaemum which is unquestion- 

 ably the same as I), humifusa. Moreover although, in most respects, 

 Muhlenberg's description is broad enough to apply to both D. san- 

 guinalis and 1). humifusa, "nodis glabris" and " Yaginis striatis glabris 

 purpurascentibus" certainly answer to the latter and not to the former. 



