108 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 8, No. 2 



6.5-12o5 cm. long, 3-5.5 cm. wide, rotund at the base, the apex abruptly short- 

 acuminate with the tip acute or obtuse, nitid and glabrous above, below rather 

 distinctly tesselate, subglaucous, appressed-puberulent, the venation nearly ob- 

 scure above, prominulous below; inflorescence racemose or rarely branched, 18-30 

 cm. long, the bracts and bracteoles minute, the pedicels 2-2.5 mm. long, the ma- 

 ture buds about 1.5 cm. long; calyx densely appressed-puberulent outside, 1.0- 

 lo5 cm. long, split into three recurved, unequal parts; petals 5, narrowly oblong 

 or oblong-oblanceolate, 2-2.3 cm. long, 5-7 mm. wide, glabrous; stamens nu- 

 merous, glabrous, the filaments about 1.5 cm. long, filiform, the anthers 5-6.5 

 mm. long, linear; stigma simple; style 1.5-2.5 mm. long, subulate, glabrous; 

 ovary oblong, 3 mm. long, 1.8 mm. wide, 3-4-ovulate, the stipe stout, 2.5 mm. 

 long, ovary and stipe densely appressed-pubescent; fruit unknown. 



Specimens Examined: "Prope Panure ad Rio Uaupes," Spruce 2802 (type no. 

 NY); "Cachoeira das Araras, Vaupes, margem do rio Vaupes," Froes 21306 (NY). 



This species is easily recognizable by the tesselate-glaucous condition of 

 the lower leaf surface, although such a condition is also present in A. latifolia 

 var. latifolia. However, the leaflets of the latter are completely glabrous and 

 those of A. discolor are appressed-puberulent on the lower surface. 



7. Aldina yapacanensis Cowan, sp. nov. 



Arbor mediocris, minutissime appresso-puberulens facie laminorum superiore 

 excepta; folia imparipinnata, unijugata, unifoliolata juxta inflorescentiam, petio- 

 lis 2-4 cm. longis, rachibus ca. 1.5 cm. longis (vel 0), petiolulis 6-9 mm. longis, 

 incrassatis, laminae 8.5 ad ca. 15 cm. longae, 4.5 ad ca. 8 cm. latae, ovatae vel 

 elliptico-ovatae, ad apicem acutae, ad basim rotundato-obtusae, supra glabrae, 

 facie inferiore pallidae, costa in facie superiore plana sed infra valde salienti, 

 venis primariis in paribus ca. 6-8, planis; inflorescentiae terminales, paniculatae, 

 erectae, ca. 15 cm. longae, rachibus ramulisque suis aureo-appresso-puberu- 

 lentibus, bracteis late triangularibus, acutis, 0.7 mm. longis, 10 mm. latis, brac- 

 teolis triangularibus, 0.5 mm. longis, 0.5 mm. latis, pedicellis ca. 5 mm. longis; 

 alabastra ovalia, ca. 1 cm, longa, calyx 10 mm. longus, in partes 4 plus minusve 

 aequales recurvatasque fissus, extra valde aureo-appresso-puberulens, intra ad 

 apicem villosulus, petala 4, (in alabastro) ovalia, sessilia, concava, 7 mm. longa, 

 5.5 mm. lata, glabra; stamina numerosa, filamentis glabris, ca. 15 mm. longis, 

 filiformibus, antheris linearibus, 6 mm. longis, 0.8 mm. latis; (pistilli ex alabas- 

 tro) stigma simplex, stylus brevis, porrectus, glaber, ovarium glabrum, oblongum, 

 7-ovulaiie, stipes articulatus, columnaris, longitudine ovarii dimidius, superiore 

 parte minutissime sericea, inferiore glabra; fructus ignotus. 



TYPE: medium tree, flowers brownish, along margin of Cano to Cerro Yapa- 

 cana, Territorio Amazonas, Venezuela, January 6, 1951, Bassett Maguire, Richard 

 S. Cowan & John J. Wurdack 30758; New York Botanical Garden. 



Aldina yapacanensis, named for the fascinating region around Cerro Yapacana 

 in which this plant was collected, is most closely related to A. macrophylla 

 Spruce from the Rio Casiquiari. The greatest point of similarity is the glabrous 

 ovary of both, the only two species in which this condition obtains. In addition, 

 both have at most three leaflets but in the new species these are very much smal- 

 ler and of different shape from those of A. macrophylla. The inflorescence of A. yapa- 

 canensis is a distinct, regularly- branched panicle while that of its nearest rela- 

 tive is very sparsely branched and to twice the length of that of the new species. 

 In respect to floral characteristics, both species have four petals which are, how- 

 ever, quite different in size and shape in the two. The number of ovules per ovary 

 is in both these groups higher than for most of the other species, seven in A. ya- 

 pacanensis and five to seven in A. macrophylla. 



