1961] 



BOTANY OF THE GUAYAXA HIGHLANDS PART IV (2) 



61 



proper affinity. It is possible, however, that the differences are more than 

 varietal and this taxon deserves the rank of a distinct species. 



Lacmellea pygmaea var. latifolia Monachino, var. nov. 



Haec varietas a var. pygmaea foliis lanceolatis vel oblongis latioribus 1-3 cm 

 latis recedit. 



Differs from var pygmaea Monachino in its lanceolate or oblong, much 

 broader leaves, 1—3 cm wide (instead of less than 0.5 cm). The flowers in our 

 specimens are somewhat larger; corolla-tube 13 mm long, anthers 4.6 mm and 

 style 2 mm long. 



VENEZUELA: Amazonas: locally abundant in Sabana Cumare on right bank of Cano 

 Cumara, Rio Atabapo, 20 km above San Fernando de Atabapo, alt. 125 m; shrub 0.2-1 m, with 

 abundant milky latex, flowers white, fruit green; 3 Jun 1959, J. J. Wurdack 4* L. S. Adderley 

 42757 (holotype, NY). Occasional in Sabana El Venado, left bank of Cafio Pimichin above 

 Pimichin, alt. 140 m; shrub 0.2-0.4 m, flowers cream; 2 Jul 1959, Wurdack 4' Adderley 43291 

 (para type, NY). 



A. pygmaea is known from only the Alto Rio Orinoco. The typical variety 

 with very narrow leaves was found in March, a drier month than June-July 

 when var. latifolia was collected. It is unknown what the seasonal or local 

 ecological effects on the gross morphology of the plant may have been. Such 

 qualms are also entertained regarding the new variety proposed in the begin- 

 ning of the present treatment of the Apocynaceae, Ambelania oleaefolia var. 

 riparia, which is likewise distinguished chiefly on size differences. 



Mandevilla obtusifolia Monachino, sp. nov. Fig. 44 A-G. 



Fruticulus scandens, caulibus subteretibus hispidulis; foliis oppositis, petiolis 

 4-5 mm longis; laminis subcoriaceis glabris oblongis 2.5-5 cm longis, 1.2-2 cm 

 latis, ad apicem rotundatis vel obtusis, ad basim rotundato-subcordatis, subtus 

 pallidis; venis lateralibus rectis, 7-10 jugis indistinctis ; inflorescentiis latera- 

 libus racemoideis paucifloris; pedicellis 3 mm longis puberulis; lobi> calycis 

 deltoideo-lanceolatis. 2.5 mm longis, 1.3 mm latis, ciliatis puberulis; squamellis 

 oppositisepalibus ; corolla infundibulariforme, tubo infrastaminali 3 cm longo, 

 intus piloso, gula 2.5 cm longa, lobis 3 cm longis, paene 3 cm latis; antheris 4.3 

 mm longis glabris 2 mm latis; ovario glabro; nectario annulari sub-5-lobulato 

 0.7 mm alto. 



Woody vine, the stems brownish, slender, subterete, puberulent-hispulous. 

 Leaves opposite ; petioles 4—5 mm long ; blades subcoriaceous, green and shining 

 above, pallid beneath, essentially glabrous, glanduliferous along the midrib on 

 the upper surface, oblong, generally broadest slightly aboA'e the middle, 2.5-5 

 cm long, 1.2-2 cm broad, rounded or broadly obtuse and minutely apiculate at 

 the apex, rounded-subcordate at the base, becoming revolute at the margins, 

 the lateral veins straightish, lightly ascending, submarginally connected. 7-10 

 pairs, faint beneath, slightly more prominent above, reticulation manifest by 

 transmitted light, open. Inflorescences appearing axillary, racemoid, few-flowered, 

 with 3-6 flowers; pedicels 3 mm long, faintly puberulent. the bracts deciduous, 

 probably squamose ; calyx-lobes deltoid-lanceolate, acutish at the apex, membran- 

 ous at the margins, 2.5 mm long, 1.3 mm broad, ciliate, puberulent dorsally. the 

 squamellae oppositisepalous, broadly deltoid, denticulate to lacerate, 0.7 mm 

 high. Corolla bright yellow, showy, large, glabrous without, infundibuliform ; 

 infrastaminal tube 3 cm long, 3 mm wide (pressed), densely pilose within below 

 the anthers, the hairs appressed, reflexed ; throat 2.5 cm long, 1.5 cm wide 



