232 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



denser than in P. distachyum, slightly tapering or obtuse at the apex, the slender 

 angled axis minutely scabrous; fascicles nearly sessile, somewhat spreading: bri 

 slender, numerous, more spreading than in P. distackyum, most of them exceeding 

 the spikelet, the innermost not conspicuously longer than the rest; spikelet similar to 

 that of P. distachyum, but minutely scabrous only or glabrous, the glumes thinner, 

 more obtuse, the first usually nerveless, often erose; sterile palea wanting; fruit scarcely 

 indurate (thinner than in P. distachyum). 



Type in the U. S. National Herbarium, no. 250836, collected on rocky slopes, 

 barranca of Metlac, altitude about 909 meters. State of Veracruz, Mexico, January 

 29, 189"), by 0. G. Pringle(no. 6075; distributed as Penniseturn bambusiforme Hemal ) 



None of the specimens seen shows the base of the plant. This species has beeo 

 confused with P. bambusiforme, from which it diners in ite smooth or nearly snim.th 

 blades, denser inflorescence, much shorter and more densely flowered, tawny pain 

 somewhat shorter bristles, less unequal in length, and in the absence of the sterile 

 palea. 



DISTRIBUTION. 



Rocky slopes, uplands of southern Mexico. 

 Verackuz: Orizaba, Bolted 1214; Mohr & Botteriin 1856. Barranca of Metlac, Pringlt 



6075. 

 Guerrero: Sierra Madre, Langlasse 849. 

 Oaxaca: Plunia, JVieZson 2484. 



14. Penniseturn bambusiforme (Foum.) Hemsl. 



Gymnoihrix banlbusiformis Fourn. Mex. PI. 2: 48. 1886. " Prope Mirador I Sch \ pi in . 

 n. 338) " is the only specimen cited. The name was earlier listed without description 

 by Ifemsley. 46 Schaffner's no. 338_has not been examined. 1 1 -s eem s, po s sib l e tha t 

 "Schaffn." may bean error. Liebmann's no. 338 is from Mirador, and the specimens 

 of this collection distributed from the Copenhagen Herbarium are labeled 

 thrix bambusaefor mis Fourn. determ. Founder," and agree perfectly with Fournier's 

 description. Fournier, however. cite3 Liebmann's no. 33S under "G. Irish 

 FT. B. K." As stated above (under Penniseturn distachyum), Fournier*s idea of that 

 species was confused. His description of G. bambusifonvis is fairly detailed. The 

 characters that point most certainly to the identification here made of G. 

 busiformis are [translated]: "Bristles unequal, of which one is constantly longer, 

 most of them twice the length of the spikelets," and "neuter floret 2-paleate." In 

 the species described above as Penniseturn prolifieum, which has been confueed 

 with P. bambusiforme. the bristles are not very unequal, the innermost one scarcely 

 noticeably longer (most of them are about once and a half the length of the spike- 

 letb and the lower floret is empty. 



Penniseturn bambusiforme Hemsl. Biol. Centr. Amer. Bot. 3: 507. 1885, nom. Qud.; 

 hid. Kew. 2: 45S. 1894. Based on Gymnothrir bambusiformis Fourn. 



Penniseturn tristachyon var. bambusiforme Leeke, Zeitschr. Naturw. 79: 33; 1907. 

 Based on Gymnothrir bambusiformis Fourn. 



Penniseturn tristachyum var. galeotliunum Leeke, Zeitschr. Xaturw. 79::'.'. 1907. 

 "Mexiko." Leeke places the various allies of P. tristachyum under that species as 

 varieties. His var. bambusiforme is based on Gymnothrir bambusiformis. hence the 

 name is a synonym of P. bambusiforme: but it is uncertain to which of the forms T eeke 

 applies the name. He includes Gymnothrir distachya Fourn. as a synonym, but in 

 his brief diagnosis says "Culrui nodi glabri." In /'. distachyum the nodes are ap- 

 pressed -hirsute; in P. bambusiforme and P. prolifieum they are glabrous or stri • 

 The diagnosis of var. yuleottianum is: "Culrni nodi pilosi; spiculae 1-1.5 mm. longae." 

 In Galeotti's no. 5871 (P. Iambus if or me) the lower nodes present are strigose but the 



48 Biol. Oentr. Amer. Bot. 3: 507. 18S5. 



