260 BULLETIN 772, U. S. DEPARTMENT OF AGRICULTURE. 



exserted peduncle, or single, in pairs, or sometimes in threes or fours, 

 the common peduncle usually inclosed by a spathelike sheath, these 

 sheaths often numerous, forming a compound inflorescence, usually 

 narrow, but sometimes in dense subcorymbose masses. Species about 

 150, in all warmer parts of the world ; about 30 species in the United 

 States, mostly in the South. 



Type species Andropogon -rirginicus L. 



Andropogon L., Sp. PI 1045, 1753 ; Gen. P1 M ed. 5, 468. 1754. Linnreus de- 

 scribes 12 species. The reference in the Genera Plantarum is to " Roy. Ingdb. 

 52." In this work, Flora Leydensis, published in 1740, Royen describes two 

 species, the first of these is later (Species Plantarum) named Andropogon lilrtum 

 by Linnaeus, and the second A. virgin icu in. The type should be chosen from these 

 two. The two species appear to be equally familiar to Royen and to Linnaeus, 

 though A. rirginicus is more fully described and has priority of position in 

 the Species Plantarum. Andropogon rir<iinicns is chosen as the type, as this 

 choice retains the generic name for its usual signification. Of the 12 species 

 originally described, 4 are retained in Andropogon, A. d-istaclu/os, A. vir- 

 ginicus, A. bicornis, and A. ischaemum. Andropogon contortus is now referred to 

 Heteropogon, A. divaricatus to Erianthus, A. nutans to Sorghastrum, A. alope- 

 curoides to Erianthus, A. scfioenantlms, A. liirtus, and A. nardus to Cymbopo- 

 gon. Andropogon fasciculatus, the last species, is unidentifiable. 



Schizachyrium Nees, Agrost. Bras. 331. 1829. The type species is Andro- 

 pogon condensatus H. B. K., upon which is based 8. condensatnm, first of the six 

 species described. Nees states, in a paragraph at the end of the generic descrip- 

 tion, that besides the species he enumerates Andropogon brevifolms belongs to 

 Schizachyrium. Because of this statement Nash 1 chooses the latter species 

 as the type. This group includes the species of Andropogon with racemes 

 single at the ends of the branches. 



Dimeiostemon Raf., Bull. Bot. Seringe 1 : 221. 1830. "Andropogon vaginatus 

 Ell., A. sessiliflorus [nomen nudurn], A. macrurus, A. vaginatus [repeated], A. 

 tetrastachys" are listed. Andropogon vaginatus Ell., which is the same as 

 A. virginicus L., is taken as the type. 



Amphilophis Nash, in Britton, Man. 71. 1901. Only one species described, An- 

 dropogon torreyanus Steud. This group includes the species of Andropogon 

 with numerous racemes in a naked panicle. Amphilophis was first used by 

 Trinius 2 as a section of Andropogon. 



Our species are divided into three groups: One (constituting the 

 genus Schizachyrium of some authors) Avith the racemes single on 

 each peduncle ; two, with the racemes in pairs, or sometimes in threes 

 or fours, on each peduncle ; three, with the racemes aggregate toward 

 the naked summit of the culms and branches. The commonest repre- 

 sentative in the United States of the first group is Andropogon scopa- 

 rius Michx. (fig. 158). This is an erect bunch-grass 2 to 4 feet high, 

 the racemes scattered along the upper part of the stem. It is common 

 throughout the eastern half of the United States. It is a fairly good 

 forage grass and forms a part of the wild prairie hay in the eastern 

 portion of the Great Plains, where it is called little bluestem. The sec- 

 ond group is represented by numerous species in the Southern States. 

 One of these, A. virginicus L. (fig. 159) is found in old fields, open 

 woods, and sterile ground from Massachusetts to Texas and Florida. 

 This is called broom sedge, though the name is also applied to some 

 of the other species of Andropogon. Andropogon virginicus is a 



iN. Amer. Fl. 17: 100. 1912. 



2 M5m. Acad. St. Petersb. VI. 2: 285. 1832. 



