286 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
15. HOLCUS L. 
Racemes reduced to 1 to 5 joints, borne on slender peduncles on the slender 
branches of a compound panicle; rachis slender, tardily disjointing; spikelets 
arranged as in Andropogon, the pedicellate spikelet usually staminate, the sessile 
spikelets awnless or with a deciduous awn. 
Plants perennial, with creeping rhizomes__________-__________ 1. H. halepensis. 
Plants annual oo - _.-2. H. sorghum, 
1. Holcus halepensis L. Sp. Pl. 1047, 1753. JOHNSON GRASS. 
Andropogon halepensis Brot. Fl. Lusit. 1: 89. 1804. 
Sorghum halepensis Pers. Syn. Pl. 1: 101. 1805. 
A robust perennial with numerous stout rhizomes, flat scabrous-margined 
blades, and a large open panicle of plump spikelets with deciduous awns, 
A weed in fields and waste places in the warmer parts of America; introduced 
from the Old World. Originally described from Syria. Found in all the large 
islands and probably in most of the smaller ones. 
This species is described by Humboldt, Bonpland, and Kunth,’ with Habana, 
Cnba, given as locality, under the name “Andropogon avenaceus Schrad.” This 
is evidently a misprint for A. arundinaceus Willd., as described by Schrader.’ 
In Cuba this is called “ caftuela ” and “ hierba de Don Carlos.” 
2. Holcus sorghum L, Sp. Pl. 1047. 1753. SORGHUM or Sorgo. 
Andropogon sorghum Brot. Fl. Lusit. 1: 88. 1804. 
Sorghum vulgare Pers, Syn. Pl. 1: 101. 1805. 
Sorghum fora Griseb. Fl. Brit. W. Ind. 560. 1864, 
A large broad-leaved annual, with a compact panicle of turgid persistent 
spikelets. 
Occasionally cultivated in the West Indies and sometimes spontaneous in 
waste places or near fields. Widely cultivated in other parts of America and 
in the Old World, whence originally described. In the English islands it is 
often called “ Guinea corn”; in Cuba it is called “ millo.” 
2a. Holcus sorghum sudanensis (Piper) Hitche. Proc. Biol. Soc. Washington 
29: 128. 1916, SUDAN GRASS. 
Andropogon sorghum sudanensis Piper, Proc. Biol. Soc. Washington 28: 33. 
1915. 
Resembling no, 1, but less robust and having no rhizomes, 
Coming into cultivation in the West Indies in recent years and sparingly 
escaped. Described from a cultivated specimen grown from seed from the 
Sudan. 
Santo Domingo, Porto Rico, and St. Vincent. 
16. SORGHASTRUM Nash. 
Racemes arranged as in Holcus, the pedicellate spikelet wanting, the pedicel 
only present; rachis flexuous, readily disjointing. 
Awn straight or slightly bent, not strongly spirally twisted at base, shorter than 
the spikelet or sometimes a little longer______________ 1. S. parviflorum. 
Awn geniculate, strongly spirally twisted at base, about 3 times as long as the 
spikelet_________-_____-__~_-- ee ee 2. 5. stipoides. 
* Nov. Gen. & Sp. 1: 189, 1816, *? Fl. Germ. 1: 237. 1806. 
