356 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1. Pentarrhaphis scabra H. B. K. 



Pentarrhaphis scabra H. B. K. Nov. Gen. & Sp. 1 : 178. pi. 60. 1816. Authentic 

 material has not been found, but the figures are good and leave no room for doubt as 

 to the identity of the species. See also Bull. Torrey Club 17 : 233. pi. 108. 1890. 



Aiheropogon pentarrhaphis Spreng. Syst. Veg. 1:294. 1825. Based upon Pen- 

 tarrhaphis scabra H. B. K. 



Eutriana pentarrhaphis Trin. Gram. Unifl. 239. 1824. Based upon Pentarrhaphis 

 scabra H. B. K. 



Polyschistis paupercula Presl, a Rel. Haenk. 1: 294. pi. 41. /■ 12-18. 1830. The 

 gures and description identify the plant. 



DESCRIPTION. 



An erect, cespitose perennial about 30 cm. high;. culms erect, commonly branched 

 from the upper nodes; sheaths loose, striate, the ligule a short, dense fringe of white 



Fig. 20.— Pentarrhaphis scabra. a, Spike; 6, c, lemma and palet of first floret; d, e, lemma and palet of 

 second floret, a, Scale 5; b-e, scale 10. From Heyde & Lux 4659. 



hairs; blades mostly radical, rather harsh, rigid, very slightly scabrous on the margin, 

 the lower 4 to 5 cm. long, the upper reduced to 2 cm. long or less;. panicle racemose, 

 loose, 4 to 5 cm. long, the rachis zigzag; spikes about 12, small, 8 mm. long, including 

 the awns, consisting of one perfect, 2-flowered spikelet and a cluster of awns below; 

 cluster of awns consisting of 5 parts, 2 of these united below, representing the con- 

 tinuation of the rachis, one slightly expanded, representing the first glume of the 

 perfect spikelet, the other two representing the aborted lower spikelet, all of these, 

 together with the upper glume, densely white-hairy; lemma of the first floret, includ- 

 ing awns, about 6 mm. long and of the second floret about 7 mm. long, both sparingly 

 hairy, the upper coriaceous j/palet slightly scabrous on the nerves, convolute, nearly 

 3 mm. long, scarcely awnea; caryopsis not seen. (Figure 20.) 



a This is from tropical America instead of the Island of Luzon, as stated by Presl. 

 See Merrill's opinion in the Philippine Journal of Science (1 : 380. 1906). 



