1963] 



BOTANY OF THE GUAYANA HIGHLANDS PART V 



145 



well as by the calyx lobes glabrous on the back. C. montana has moderately to 

 densely glandular-puberulous hypanthia, young leaves, and calyx lobes. No other 

 vegetative or reproductive criteria serve for separation. The type sheet of C. 

 montana consists of six sprigs, of which the upper three are C. coriacea and the 

 lower three (including the holotype) are C. montana. The two species are known 

 from the Chimanta Massif by the following collections : 



C. coriacea— Wurdack 34171, 34206, Steyermark & Wurdack 627, 722, 740. 

 C. montana — Steyermark i( - Wurdack 447, 542, 723, 741. 



Mallophyton Wurdack, gen. nov. 



Tribus Tibonchineae. Pubescentia lanuginosa, pilis tenuibus debilibus. Flores 

 4-meri. Stamina vix anisomorphica, connective) basi prolongato incrassato. 

 Ovarium 3-loculare glabrum. Genus monotypicum. 



Mallophyton chimantense Wurdack, sp. nov. Fig. 63, a-j. 



Frutex 0.1-2 m; ramuli novelli foliis subtus hypanthiis sepalisque densissime 

 lanuginoso-pubescenti, pilis primum rufescentibus demum pallidis ; rami teretes 

 demum decorticantes. Folia vix (ad 3 mm) petiolata, 2-4 X 2-3 cm late ovata 

 vel late elliptico-ovata, apice hebeti-obtusa vel rotundata basi vix (2-5 mm) 

 cordata crasse rigideque coriacea convexa supra ferrugineo-lanuginosa mox 

 glabrata, 5-7-nervata nervis primariis lateralibus supra invisis subtus crasse 

 elevatis nervis secundariis tertiariisque supra invisis subtus vix evolutis mar- 

 ginibus recurvatis. Flores in dichasia triflora sessilia terminalia aggregati. 

 Hypanthium (ad torum) 5 X 4-4.5 mm; calycis tubus 0.7 mm altus, lobis 2.5 

 mm longis subulatis angnste aeutis basi valde remotis. Petala 16-17 X 15-16 mm 

 asymmetrice obovata apice truncata glabra eciliata. Filamenta 9 vel 8-8.5 mm 

 longa glabra; antherarum thecae 4.2 vel 3.9 mm longae, connectivo basi 1.1 vel 

 0.7 mm prolongato ventraliter ad basim 1 X 0.8 mm obovato vel oblongo-obovato. 

 stylus 15x0.4 mm glaber ; stigma punctiforme. Capsula trivalvata; semina 

 cochleata inconspicue denseque muriculata. 



Type. Petals deep pink, anthers yellow, frequent in swampy depression in 

 savanna along east branch of headwaters of Rio Tirica, central section of 

 Chimanta Massif, Edo. Bolivar, Venezuela, alt. 2100 m, 12 Feb 1955, J. A. Steyer- 

 mark ct* J. Wurdack 766 (holotype US 2342408). Paratypes: VENEZUELA, 

 Edo. Bolivar. Chimanta .Massif : savanna below summit of western escarpment, 

 Torono-tepui, alt. 2100 m, Steyermark & Wurdack 679; east-central portion of 

 summit of Apacara-tepui. alt. 2150-2200 m, Steyermark 75882. 



The tepui species of Comolia have similar stamens, but qualitatively very 

 different pubescence and a two-celled ovary. The species of Acisanthera Sect. 

 Acisanthera have 3-locular ovaries, but predominantly 5-merous flowers with 

 definitely bilobed ventral connective appendage and non-woolly pubescence ; the 

 species are herbaceous or scarcely woody. 



Pachyloma pusillum Wurdack, sp. nov. Fig. 66, a-c. 



A congeneribus differt foliis uninervatis basi attenuatis. 



Suffrutex ad 25 cm altus non vel vix ramosus ; caulis glaber vel primum 

 sparsissime glanduloso-setulosus demum glabratus. Folia sessilia vel vix (ad 1 

 mm) petiolata glabra 2.5-5.5 X 0.3-0.7 cm lanceolato-elliptica apice basique acuta 



