360 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



epikelet densely covered with long straight hairs, that of each lateral spikelet about 

 3 mm. and of the upper one about 4 mm. long, the first glume of each lateral spikelet 

 less hairy and only 2 mm. long, that of the upper spikelet reduced to a broad fan- 

 shaped, nerveless scale scarcely 1 mm. in length; lemmas of the lower spikelets 

 sparsely short-hairy, coriaceous, 2 to 3 mm. long, short-awned; palets convolute, 2- 

 nerved, slightly scabrous at the tip, not awned; awns of palet of third spikelet about 



2 mm. long and more scabrous, the parts of the third floret much reduced; caryopsis 

 not seen. (Figures 22, 23.) 



The above description is drawn from Pringle's no 8707, upon which the large spikes 

 are by far the most abundant, but upon the same specimens there are other spikes 

 which are the same as those of the type. 



The Haenke specimen is uniform in having small spikes with the lateral spikelets 

 more or less aborted. The Pringle specimen, on the contrary, shows the species to 

 be dimorphic. 



Founder refers one of Schaffner's specimens without locality to this species, but I 

 have seen only the fragment of the type mentioned above and Pringle 8707, collected 



on limestone hills near 

 Jojutla, Morelos, Mexico. 

 It is more than likely 

 that the description will 

 have to be modified 

 somewhat in the future, 

 for all specimens seen 

 are immature. 



2. Cathestecum mul- 

 tifidum sp. no v. 



DESCRIPTION. 



A delicate, upright, 

 hairy, cespitose peren- 

 nial, about 40 cm. high; 

 culms erect, delicate, 

 simple; sheaths striate, 

 close, with a few scat- 

 tered hairs above ; ligule 

 a fringe of a few long 

 white hairs ; blades abun- 

 dantbelow,flat, longand 

 narrow, 10 to 15 cm. long, a trifle over 1 mm. wide, the upper reduced, thinly beset with 

 long, straight or flexuous, white hairs, 2 to 3 mm. long, arising from papilla?; panicle 

 racemose, 5 to 6 cm. long, on a zigzag axis; spikes about 15, small, 4 to 5 mm. long 

 over all, roughly triangular in outline, the rachis prolonged as a barbed, simple or bifid 

 awn, usually less than 2 mm. long, with or without a very small winged expansion 

 on one side; lateral spikelets 2-flowered, the rachilla prolonged into a blunt or bifid 

 awn behind the palet of the second floret, or often the upper floret aborted and reduced 

 to a bunch of awns upon a naked stipe; central spikelet 2-flowered, with a well-devel- 

 oped third floret consisting of 6 to 10 expanded awns on a naked stipe; glumes pubes- 

 cent, narrow, acuminate or short-awned, the first about 2 mm. long, the upper about 



3 mm. long; lemma of the lower floret about 2. 5 mm. long overall, bearinga few scattered 

 hairs, 3-nerved,3-awned, the awns very short; palet plicate, about 2. 5 mm. long, scarcely 

 awned; lemma of the second floret becoming 5 to 7-awned by the splitting of each 

 of the normal lateral nerves into 2 or 3, 3 to 5 mm. long; lower floret of upper spike- 

 let apparently pistillate only, the others staminate; caryopsisnot seen. (Figure 24.) 



The type of this species was collected by myself at Iguala, Mexico, September 9, 

 1909. It was later collected at Oaxaca, Mexico, by Hitchcock (no. 6164). It is an 



Fig. 24.— Cathestecum multifidum. a, Spike; 6, uppermost spikelet; c, d, 

 lemma and palet of first floret; e, f, lemmas of second and third florets; 

 g, h, two views of caryopsis; i, one of lower pair of spikelets; j, k, lemma 

 and palet of lower floret, a, Scale 5; b-f, scale 7.5; g-i, scale 10; ,;, h, scale 

 7.5. From type specimen. 



