22 



FIELD COLUMBIAN MUSEUM BOTANY, VOL. III. 



margins ciliate; third shorter, hyaline, ciliate, subtending a similar 



palea and staminate flower or empty; pedicel YI-% the length of ses- 

 sile spikelet. Perfect spikelet 

 6 mm., ovate, sub-acute, with a 

 ring of hairs at the base; first 

 and second glumes light brown 

 to chestnut, pubescent; first 

 y-nerved, obtuse; second 

 5 - nerved, apiculate, ciliate; 

 third shorter, white or purple- 

 blotched, hyaline, 2 - nerved, 

 ciliate; floral glume ^ the 

 length of first, cleft y$ its 

 length,- ciliate, bearing a genic- 

 ulate awn 8-10 mm long, and 

 subtending a minute linear, cil- 

 iate palea. Grain reddish 

 brown, oval, 2.4x3.6 mm.; in 

 section oblong with concave 



ventrum and truncate-convex dorsum. 



Hab. " In an old field at Buena Vista Xbac, 3 feet high," April, 



Gaunter 1053. (Andropogon Sorghum Drummondii Hack. Field Col. 



Mus. Bot. 1:350). 



Sorghum vulgare Pers. Syn. i.ioi. 



Panicle short-exserted, 10-12 cm. long, dense and compact; 

 branches alternate, short, at first pubescent, becoming glabrous or 

 nearly so, pubescent in the axils. Racemes of 1-4 inarticulate joints, 

 internodes 2 mm. long, pubescent. Pediceled spikelet 3-4 mm., lan- 

 ceolate, pubescent; first glume acute, 8-nerved, the lateral strongest 

 and hispid, margin ciliate; second equal in length, y-nerved, ciliate, 

 enclosing a smaller ciliate, hyaline, empty glume; pedicel ^ the length 

 of sessile spikelet or less, pub- 

 escent. Perfect spikelet 6 mm. , 

 ovate, with a ring of hairs at the 

 base; first and second glumes 

 chestnut or black and shining 

 when mature, at first densely pu- 

 bescent, becoming more or less 

 glabrous, first 2-nerved, blunt; 

 second 3- nerved, apiculate and 

 having a hyaline-fimbriate mar- 

 gin; third shorter, white, hya- 

 line, 2-nerved, ciliate; floral 

 glume less than y? the length 

 of first, cleft YZ its length, cili- 

 ate, bearing a geniculate awn, 

 5 mm. long, and subtending a 

 minute lanceolate, fimbriate 



palea. Grain reddish brown, oval, 2^x4.4 mm. ; in section oblong 

 with slightly concave ventrum and convex dorsum. 



Hab. Chichankanab, Gaunter 2155. 



