1961] 



BOTANY OF THE GUAYANA HIGHLANDS PART IV (2) 



67 



1. Stipules 9-10 mm long, 3 mm wide, acute; piuuae 1-2-jugate, the leaflets 18-21- 

 jugate, albo-villose beneath, the eosta strongly expressed, excentric. Filaments 21 

 mm long. 0. resupina. 



Inga gracilifolia Ducke. 



VENEZUELA: Amazonas: along Rio Cuao, alt. 125 in; tree 12 m tall; fls green with 

 pale yellow filaments; 19 Jan 1949, Maguire 4' Politi 28439. 



This is probably a very widespread species in northern South America, at 

 least in the Amazon Basin. It was described on the basis of collections from 

 Belem, one from the Rio Trombetas in northern Brazil, and one from western 

 Brazil on the Rio Solimoes. This Venezuelan collection represents a very signi- 

 ficant northward extension of range and this is the first report of the species 

 in Venezuela. 



Inga racemiflora Ducke. 



VENEZUELA: Amazonas: locally frequent along flooded forest edge south and east 

 of Maroa, Kio Guainia, alt. 130 m; shrub 3-5 m; corolla greenish-white; filaments white; 

 4 Jul 1959, Wurdack & Adderley 43313; occasional along Rio Yatua between mouth and 

 Laja Catipan, alt. 110-120 m; tree 6 m; fls white; 13 Jul 1959, Wurdack # Adderley 43430. 



The presence of this species in southwestern Venezuela is not unexpected, 

 since it has been known previously from the Rio Negro region of northwestern 

 Brazil. This is the first report for Venezuela, however. 



Pithecellobium aquaticum (Pittier) Cowan, comb. nov. 



Macrosamanea aquatica Pittier, Bol. Soc. Venez. Ci. 11:15. 1950. 



Four recent collections have been referred to this species ( Maguire et al. 36204, 

 36253; Wurdack & Adderh y 12732; Level 70) • all are from the San Fernando 

 de Atabapo region, just up-river from the type locality. Since the generic 

 name under which Pittier published his new species is not generally accepted, 

 it seems advisable to provide the combination under Pithecellobium. 



Pithecellobium arenicola Cowan, sp. nov. Fig. 46. 



Arbor 2-3 m alta vel arbuscula 0.3-1.5 m alta, ramulis puberulis, stipulis 

 caducis, non visis. Petiolus 9—16 mm longus, puberulus, ad apicem glandula 

 ovali 3 mm longa ornatus, rhachi (0-) 12-16 mm longa, puberula, pinnis 1-2- 

 jugatis, petiolo secondario ca. 4 mm longo, rhachillis 7.5-16 cm longis, puberulis, 

 petiolulis nullis. Foliola 16-24-ju<rata, rigida, glabra (puberula costa supra ex- 

 cepta), leviter falcata, laneeolata ad oblongo-lanceolata, 20-30 mm longa, 5-7 

 mm lata, ad basim inaequilateraliter rotundata, ad apicem acuta et mucronata, 

 costa excentriea venis primariisque leviter impressis supra, infra leviter salienti- 

 bus. Flores capitati, capitulis in racemis terminalibus dispositis, capitularum 

 pedunculo 5-10 mm longo, dense puberulo, bracteis glandulas conspicuas 

 ferentibus. Calyx minuto-strigulosus, viridis, tubo 6-7.5 mm longo, lobis 2.5-3.5 

 mm longis, anguste triangularibus, acutis; corolla luteo-gilva, minute strigulosa, 

 tubo 15-17 mm longo, lobis 5.5-6 mm longis, ca. 2 mm latis, triangulari- 

 lanceolatis. Filamenta glabra, ca. 40 mm longa, tubo ca. 20 mm longo; ovarium 

 minute strigulosuin, sessile. Fructus immaturus plus minusve oblongup, minute 

 strigulosus, compressus. 



VENEZUELA: Amazonas: occasional in savanna on right bank of Rio Pacimoni 50 

 km above mouth, alt. 100-140 m; shrub 0.3-1.5 m tall; fls white; 7 Feb 1954, Bassett Maguire, 

 John J. Wurdack 4' George S. Bunting 37568 (holotype, US Nos. 2281823, 2281824 s ) ; fre- 



