1957] 



THE BOTANY OF THE GUAYANA HIGHLAND — PART II 



245 



Culms as much as 5 m tall, leafless for as much as 3 m, solid, glabrous; leafy 

 branches 2 or 3 together, 0.6-1.7 m long; sheaths about 9 cm long, the exposed 

 portion mostly 1.5-3 cm long; blades of the sterile culms 45 cm long, about 9 cm 

 wide near the rounded clasping base, not cordate, one margin thickened, rounded, 

 scabrous, the other flattened, hispidulous-ciliate; inflorescence 60-80 cm long, 

 with numerous narrowly ascending to somewhat spreading, rather slender racemes, 

 the lower ones as much as 18 cm long, bearing short rather distant branchlets in 

 the lower half, the axis nearly glabrous, the branches and branchlets sparsely to 

 densely pubescent especially toward the base; spikelets 2-3-flowered, the upper 

 floret reduced or rudimentary, the pedicels 2-4 mm long, appressed, glabrous 

 or usually pubescent; first glume narrow, 2-3 mm long, the tip flat or laterally 

 compressed, hispidulous; second glume 2.5-5 mm long, including the laterally 

 compressed hispidulous tip from very short to as much as 1 mm long; sterile 

 lemma similar to the second glume, equaling it or somewhat longer; lemma of first 

 fertile floret 4.0-4.3 mm long, subobtuse, the midnerve thickened and sometimes 

 rounded at the tip, the tip and sometimes the margins more or less hispidulous; 

 palea obtuse, exceeding the lemma 0.5 mm; rachilla pubescent, the joint 0.5 mm 

 long, rather stout, the second more slender, 1.0 mm long. 



TYPE: West Rim north of Camp Caffo, elev. 2000 m, Serranfa Paru, Rfo Paru, 

 Carlo Asisa, Rio Ventuari, Terr. Amazonas, Venezuela, January 31, 1951, R> S. 

 Cowan & John J. Wi&dack 31076; U.S. National Herbarium Nos. 2,040,247 and 

 2,040,248. 



12* Myriocladus grandifolius Swallen, sp. nov. Figure 3h. 



Culmi usque ad 3 m alti; culmorum fertilium rami 2.4 m longi, basi 1.5 cm 

 crassi; vaginae glabrae, in ore fimbriatae; ligula exteriore crassa, glabra, irre- 

 gularis; ligula 1 mm longa, glabra, truncata; laminae 26 cm longae, 12 cm latae, 

 subcordatae, epetiolatae, acutae, glabrae, marginibus obscure scabrae; panicula 

 68 cm longa, ca. 8 cm lata, racemis numerosis anguste adscendentibus vel paten- 

 tibus, 4-6 cm longis vel ad sumraam brevioribus, axe dense pubescens; spicula 

 floribus fertilibus 2; gluma prima angusta, pubescens, ad summam hispidula; 

 gluma secunda latior, 5-6 mm longa, pubescens, abrupte acuta, arista 2 mm 

 longa; lemma sterile 4.5 mm longura, glabrum, glumam secundam simulans; lemma 

 fertile primum 5.5-5.7 mm longum P acutum, glabrum, summo hispidulum, margini- 

 bus minute ciliatum; palea quam lemmate angustior, 3 mm longa, inter carinam 

 pubescens, summo hispidula nerviis minute excurrentibus. 



Culms as much as 3 m high; flowering branch 2.4 m long, about 1.5 cm thick 

 at the base (including the persistent sheaths); exposed portion of sheaths about 

 3 cm long, glabrous, fimbriate in the throat, the rim thick, irregular, glabrous; 

 ligule 1 mm long, glabrous, truncate; prophyllum broad, conspicuous, extending 

 2 cm above the sheath; blades 26 cm long, about 12 cm wide toward the base, 

 subcordate, the junction with the sheath 2 cm wide, not petiolate, glabrous, the 

 tip acute, the margins glabrous or obscurely scabrous; inflorescence long-ex- 

 serted, 68 cm long, about 8 cm wide, the very numerous, relatively stout branches 

 spike let -bearing to the base, narrowly ascending to spreading, mostly 4-6 cm 

 long, shorter and denser toward the summit, solitary or usually arranged in groups 

 of two or three, a densely pubescent pulvinus at the base, the axis and branches 

 densely pubescent; spikelets immature, apparently with two fertile florets and a 

 rudiment, the rachilla scabrous, the segment above the sterile lemma 0.5 mm 

 long, the segment above the fertile floret 1 mm long; first glume narrow, tapering, 

 pubescent on the back, hispidulous toward the tip; second glume broader, some- 

 what abruptly narrowed above, 5-6 mm long including the awnlike tip as much as 

 2 mm long, pubescent on the back, hispidulous toward the tip; sterile lemma 4.5 



