144 Chase — Notes on Genera of P nicetz. IV. 



Trinius (Mem. Acad. St. Petersb. VI. Sci. Nat. 3* : 105, 320. 1834) 

 makes Ichnanthus (spelling it " Ichnantus ") a section of Panicum, with 

 the synoptical heading " Flosculus * * * hermaphroditus basi faciei 

 utrinquecanaliculato-scrobiculatus vel ( plerumque) anricnlato appendicu- 

 latus," thus indicating the group as to-day accepted, including species 

 iu which there is a scar or excavation at base as well as those having 

 appendages. 



Steudel (Syn. PI. Glum. 1 : 93. 1854) follows Trinius. 



Bentham (Fl. Hongkong. 413. 1861 ) adopts Ichnanthus as a genus in 

 this emended sense, including in it I. pallens (Sw. ) Munro. 



Grisebach (Fl. Brit. W. [nd. 550. 1864) gives it, in the same sense, as 

 a section of Panicum. 



Doell (.Mart. Fl. Bras. 2 2 : 276. 1877) maintains Ichnanthus as a 

 genus for the group segregated as Panicum, section Ichnanthus by 

 Trinius, making under it two divisions " I Yalvula inferior ad basin 

 utrinque auriculatus" and li II Yalvula inferior ad basin utrinque 

 scrobiculata." 



Bentham (Benth. & Hook. Gen. PI. 3 : 1103. L883) and HackeKEngler 

 & Prantl, Pflanzenf. 2 2 : 36. 1887) maintain Ichnanthus as a genus for 

 this larger group. 



(Schultes, Mant. 2 : 281. L824, misspells the name "Ischnanthus.") 



Description. — Inflorescence paniculate, the spikelets mostly short- 

 pediceled along the usually sub-simple branches; spikelets more or less 

 laterally compressed, the glumes and sterile lemma strongly nerved; first 

 glume usually more than half the length of the spikelet, broad, acute; 

 second glume and sterile lemma subequal, acute, exceeding the fruit, the 

 Lemma enclosing a membranaceous palea and rarely a staminate flower; 

 fruit acute or subacute, indurated, the margins of the lemma usually flat, 

 the rachilla produced below the lemma into a usually minute stipe, this 

 bearing on either side membranaceous appendages adnate to the base of 

 the lemma and free above, the appendages sometimes wanting and indi- 

 cated by minute excavations only. Perennials, usually with lanceolate 

 blades abruptly contracted into a petiole-like base; the genus mostly con- 

 fined to the tropics of the western hemisphere, one species extending into 

 the Old World. 



Ichnanthus is closely allied to Panicum and appears to be but a loosely 

 coherent genus, several of the species differing from each other almost as 

 much as some of them differ from species of Panicum. A few species, 

 such as I. lanceolatus Scribn., in which the appendages are wholly want- 

 ing and even the scars obscure (but in which the lemma margins are 

 Hat), are nearly as referable to one genus as to the other. 



19. Genus LASIACIS (Griseb.) Hitchc. 



Lasiacis Hitchc. Contr. Nat. Herb. L5 : 16. 1910. "The type of the 



genus is Lasiacis divaricata (L. ) Hitchc, based on Panicum dirar teat um 





