402 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[Vol. 9, No. 3 



breviores, supra ad basin dense pilosae marginibus scabrissimae; panicula 

 pyramidata, 14 cm longa, 12 mm lata, ramis adscendentibus ramulis divergentibus, 

 superne paucifloris; spiculae 3.2-3.4 mm longae; gluma prima lata, acuta, spicula 

 ca. l /i brevior carina scabra; gluma secunda et lemma sterile aequalia fructum 

 superantia, glabra vel ad summum scabra; fructus 2.6-2.7 mm longus, laevis, 

 f lavidus. 



Perennial; culms stiffly erect from a decumbent, rhizome-like base, 110 cm 

 high, glabrous; basal leaves crowded, the blades 8-12 mm wide, becoming loosely 

 curled; sheaths of the culm leaves elongate but much shorter than the internodes; 

 ligule wanting; blades very firm, erect, gray-green. 25-30 cm long, 7-8 mm wide, 

 the upper smaller, densely pilose on the upper surface toward the base, the margins 

 very scabrous; panicle pyramidal, 14 cm long, about 12 mm wide, the branches 

 stiffly ascending, the divergent branchlets bearing a few spikelets above the middle; 

 spikelets 3.2-3.4 mm long; first glume broad, acute, a little more than half as 

 long as the spikelet, the midnerve prominent, scabrous; second glume and sterile 

 lemma equal, pointed beyond the fruit, glabrous, or scabrous on the midnerve 

 toward the summit; fruit 2.6-2.7 mm long, smooth, straw-colored. 



TYPE: locally frequent, scrub forest near Summit Camp, Central Section, 

 Chimanta Massif, alt. 1925 rn, Bolivar, Venezuela, February 2, 1955 Julian A. 

 Steyermark & John /. Wurdack 351 (US 2,182,119). 



Panicum steyermarkii Swallen, sp. nov. 



Perenne; culmi erecti basi decumbentes, ca. 60 cm alti; folia ad basin conferta; 

 vaginae solutae, glabrae, basi sparse pilosae; laminae erectae, subattenuatae, 

 planae, 20-25 cm longae, 5 urn latae, glabrae; culmorum folia 2, elaminata, 

 supremum basin paniculae attingens; paniculae 7-8 cm longae ramis paucis 

 adscendentibus inferioribus usque ad 5 cm longis; spiculae 3.6-4.0 mm longae 

 pedicellis appressis, lateralibus spicula multo brevioribus; gluma prima acuta, 

 spicula ca. l / 2 brevior; gluma secunda et lemma sterile fructu longiora, gluma 

 lemmate sterili paulo brevior; fructus acuminatus, 3 nim longus. 



Perennial; culms erect from a somewhat decumbent base, about 60 cm high; 

 leaves mostly crowded toward the base, the sheaths loose, glabrous except for a 

 few hairs at the base, the blades erect, subattenuate, flat or becoming loosely 

 rolled, about 20-25 cm long, about 5 nim wide, entirely glabrous; culm leaves 2, 

 the uppermost sheath reaching the base of the panicle, bladeless; panicles 7-8 cm 

 long, the few branches stiffly ascending, the lower ones as much as 5 cm long; 

 spikelets 3.6-4.0 mm long, glabrous, the pedicels appressed, rather stout, the 

 lateral ones usually much shorter than the spikelet; first glume acute, a little 

 more than half as long as the spikelet; second glume and sterile lemma pointed 

 beyorfd the fruit, the glume a little shorter than the lemma; fruit acuminate, 3 mm 

 long. 



TYPE: frequent along banks of Can*o Mojado, east of north escarpment, below 

 upper falls of Carlo Mojado, alt. 1895-1910 m, Torono-tepui", Chimanta Massif, 

 Bolivar, Venezuela, February 20, 1955, Julian A. Steyermark & John /. Wurdack 

 954 (US 2,182,133). Also collected along river banks in a scrub forest near Sum- 



Explanation of figure 75 



FIG. 75. Ischaemum arenosum Sohns. a, plant; b, pair of spikelets; c, first glume; d, 

 second glume; e, lemma and pale a of lower floret; /, fertile lemma; g, palea and one 

 lodicule; h, stamens (only two shown); i, caryopsis; pedicel; k, first glume; 1, second 

 glume; m, lemma and palea of lower floret; n, stamen and lodicule; o, fertile lemma; p, 

 palea and essential organs; q, ligule, sheath, and blade, j-p from the pedicellate spikelet. 

 a X Vi\ b-p, x 8; q, x 5 (type). 



