124 



CONTRIBUTIONS FEOM THE NATIONAL HEKBAEIUM. 



DESCRIPTION. 



Culms ascending from a decumbent base, becoming spreading and much-branched, 

 somewhat compressed, the line of pubescence sparse or wanting; sheaths densely 



papillose-ciliate, otherwise glabrous; blades 4 to 

 10 cm. long, 10 to 18 mm. wide, lanceolate, acu- 

 minate, narrowed to the roimded base, more or 

 less pilose on both surfaces; panicles 5 to 12 cm. 

 long, the few, distant, racemes 0.8 to 2 cm. long, 

 ascending or finally spreading; spikelets 3.6 mm. 

 long, about 1 mm. wide, pointed; first glume 

 scarcely one-third the length of the spikelet, his- 

 pid along the midnerve and margin; second glume 

 shorter than the sterile lemma, 7-nerved, hispid, 

 the hairs longer toward the summit and margin, 

 the sterile lemma 5-nerved, hispidulous and along 

 the margins hispid, bearing at either side of the 

 midnerve a crateriform gland, these more promi- 

 nent than in P. pulchellum., the sterile palea nearly 

 as long as its lemma, hispidulous; fruit 2.4 mm. long, 0.7 mm. wide, elliptic, minutely 

 stipitate. 



In the original description of P. biglandulare the margins of the sheaths are de- 

 scribed as "clothed with glands bearing branching hairs." The hairs are found to be 

 simple and arising from papillae. 



DISTRIBUTION. 



Fig. 117.— P, biglandulare. 

 specimen. 



From type 



Among bushes, mountains of Mexico and Guatemala. 



Mexico: Near Pinabete, Nelson 3781. 

 Guatemala: Coban, Tuerckheim II 1956. 



Parviglumia. — Plants erect or ascending, usually from a decumbent base; culms 

 slender; sheaths densely ciliate and with a dense ring of pubescence at the 

 summit; ligules less than 0.5 mm. long; blades firm, lanceolate, constricted 

 into a very short petiole-like base, and having a thin, white, cartilaginous 

 margin; panicles light green, with few, compactly flowered branches; spike- 

 lets not over 2 mm. long, obovate, obtuse, glabrous, the first glume usually 

 about one-fifth the length of the spikelet; fruit, except in P. parviglume, with 

 scattered, appressed, silky hairs. 



Besides the three here given two Brazilian species belong in this gi'oup: 

 P. trichidiachne Doella and P. schiffneri Hack.,^ and also P. conchatum 

 Foum.c described from a Mexican specimen.'^ 



Blades 12 to 16 cm. long, 2 to 3 cm. wide; fruit glabrous 70. P. parviglume. 



Blades not over 10 cm. long nor 1.8 cm. wide; fruit with 

 scattered silky hairs. 



Blades scabrous on the upper surface, not falcate 68. P. virgultorum. 



Blades sparsely hispid on the upper surface, falcate 69. P. schmitzii. 



ain Mart. Fl. Bras. 2^: 339. pi. 49. 1877. 

 ^Denkschr. Math.-Naturw. Akad. Wiss. Wien 79 

 cMex. PI. 2: 25. 1886. 

 <^See P. conchatum Foum. page 329. 



11. 1906. 





