126 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



branches finally somewhat spreading, pubescent at the base, bearing short, appressed, 

 approximate branchlets of crowded spikelets along the upper two-thirds to three- 

 fourths of their length; spikelets 1.8 mm. long, 0.9 mm. wide; first glume scarcely 

 one-fifth the length of the spikelet; second glume slightly longer than the sterile 

 lemma, both 5-nerved; fruit 1.5 mm. long, 0.8 mm. wide, oval, the lemma sparsely 

 clothed with appressed, silky hairs, the palea glabrous. 



DISTRIBUTION. 



Shaded rocky slopes, southern Mexico. 

 Mexico: Las Canoas, San Luis Potosi, Pringle 3817. 



70. Panicum parviglume Hack. 



Panicum parviglume Hack. Oesterr. Bot. Zeitschr. 51: 429. 1901. "Costarica: in 

 ripis fl. Rio Torres prope S. Jose (Pittier 9080), prope S. Francisco de Guadalupe 

 (Tonduz, 2448)." The type, Pittier 9080, is in Hackel's herbarium. 



DESCRIPTION. 



Culms slender, erect, from an ascending base, 100 cm. high, striate, sparsely papil- 

 lose-pilose; sheaths exceeding the internodes, ciliate, sparsely papillose-pilose, striate, 



more densely pubescent at the juncture with the 

 blade; ligules very short, ciliate; blades lanceolate 

 or linear-lanceolate, 8 to 16 cm. long, 12 to 25 mm. 

 wide, flat, firm, rounded at base, acuminate, sparsely 

 hispidulous, especially above, the margin very sca- 

 brous; panicles ovate, 15 to 25 cm. long, the branches 

 spreading or ascending, the lower distant, solitary, 10 

 to 12 cm. long, the lower fourth naked, bearded at 

 base; branchlets appressed, the longer 1 to 2 cm. long, 

 bearing 3 to 8 subcontiguous spikelets on slender, 

 flexuous, scabrous pedicels 0.5 to 2 mm. long; spike- 

 lets oval, 2 mm. long, 1.2 mm. wide; first glume about one-fifth the length of the 

 spikelet; second glume and sterile lemma equal, slightly exceeding the fruit, faintly 

 5-nerved, minutely apiculate; fruit smooth. 



Fig. 120.— P. parviglume. 

 type specimen. 



From 



DISTRIBUTION. 



Thickets along streams, southern Mexico and Costa Rica. The only complete speci- 

 men in the National Herbarium is Tonduz 's no. 8448 from which the above descrip- 

 tion is drawn. This was collected by Tonduz and Pittier at San Francisco de Guada- 

 lupe, Costa Rica, "Buissons sur les bords du Rio Torres." 



In the National Herbarium there is a panicle, with upper leaf, of a plant of this 

 species, with the specimen of Botteri's no. 150, collected in Mexico. A similar frag- 

 mentary specimen is mixed with the same collection in the Gray Herbarium. 



Verrucosa. — Glabrous annuals with weak, divaricately branching culms, decumbent 

 at base and usually provided with aerial brace-roots at the lower nodes, the 

 lower internodes much shorter than the middle and upper; ligules ciliate, 

 not over 0.5 mm. long; panicles with divaricate, capillary branches, spikelet- 

 bearing toward the ends; spikelets tuberculate; fruit minutely papillose, 

 the margin of the lemma flat, inrolled only at base. 



Spikelets about 2 mm. long, glabrous 71. P. verrucosum. 



Spikelets over 3 mm. long, hispid 72. P. brachyanthum. 



