1958] 



THE BOTANY OF THE 6UAYANA HIGHLAND PART III 



121 



LA: Amazonas: Maguire & Wurdack 34909, Rio Casiquiare and tributaries, 

 occasional along Rio Pacimoni between Canos Arapacua and Boridahari, elev. 

 110 m, April 7, 1953, spare tree 5-7 m, fruit brown. 



The leaves of A. exalatum were not matched with any species heretofore de- 

 scribed. The venation somewhat recalls that of A. verruculosum Muell.-Arg., but 

 the secondaries are much further apart. The reduced thickened wing of the seed 

 is a feature which was not noted for any species of Aspidosperma by Woodson 

 in his monograph of the genus. However, A. Ducke (Anais Acad. Bras. Ci. 27: 

 382. 1955) mentions such a wing for A. nitidum Benth. ex Muell.-Arg. Fruiting 

 material is not available for many species and consequently it remains to be 

 seen how rare exalate seeds are in the genus. 



Aspidosperma glaucum Monachino, sp. nov. Figure 15. 



Arbor ; ramulis glabrescentibus ; foliis alternis coriaceis subglabris ; petiolis 

 ca. 2 cm longis; laminis oblongo-obovatis vel obovatis, 10-12 cm longis, (3-) 4-6 

 cm latis, ad basin cuneatis, ad apicem obtusis, supra nitidis, subtus glaucis; 

 aervis secundariis debilibus; venis obscuris; fructibus crasse lignosis ovali-pyri- 

 formibus, ca. 12 cm longis, 8.5 cm latis, glabris minute rugulosis; seminibus 

 orbicularibus, 7-8 cm latis, membranaceo-alatis ; cotyledonis late ovatis, ca. 3 cm 

 longis, 2.5 cm latis ; radicula ca. 5 mm longa, lobos cotyledonorum excedenti. 



Tree 20 m tall, essentially glabrous, the branchlets moderately thick, brown- 

 ish, glabrescent, the buds grey-tawny-puberulent ; leaves alternate or approxi- 

 mate ; petiole 0.8-2.3 cm long, brownish, sometimes sparsely appressed-puberulent 

 particularly toward the base ; blade coriaceous, oblong-obovate or obovate, cune- 

 ate at the base, very short-acuminate or rather apiculate at the apex, revolute 

 at the margins, 10-12 cm long, (3-) 4-6 cm wide, essentially glabrous, a few 

 scattered hairs' (up to about 0.17 mm long) sometimes present particularly 

 along the midrib, shining above, strikingly glaucous-colored beneath (covered 

 with scurfy material that can be scraped off), the secondary nerves faint, not 

 raised, the principal ones averaging 5-10 mm apart near the middle of the blade, 

 the veins obscure; fiWers lacking; follicle (unattached) thickly woody, oval- 

 pyriform, about 12 cm long, 8.5 cm wide, glabrous, the surface minutely rough- 

 ened, the ridge 3.5 cm from the nearest margin ; seeds papery-winged, more or 

 less orbicular, 7-8 cm wide ; cotyledons broadly ovate, shallowly cordate at the 

 base, about 3 cm long, 2.5 cm wide; radicle 5 mm long, surpassing the lobes of 

 the cotyledons. 



Type : Bassett Maguire & Louis Politi 28255, Cerro Sipapo, Territorio Ama- 

 zonas, Venezuela, cumbre, Savanna Camp to Cano Profundo and East Terrace 

 via Cano Negro, elev. 1600 m, Jan 8, 1949, tree 20 m high, 20 cm diam., leaves 

 glaucous beneath, seed broadly membranous winged (holotype NY). 



In its coriaceous, glabrous, glaucous-colored leaves, A. glaucum recalls A. 

 excelsum Benth. (altogether different in its spinose-verrucose follicles), the pallor 

 on the under side of the leaves of the former being more marked. The leaves of 

 our new species seem to differ further in being apiculate at the apex, in having 

 revolute margins and secondary nerves appreciably fainter. The buds are tawny- 

 tomentulose, not grey as in A. excelsum. 



As indicated above, A. glaucum is easily and with certainty separated from 

 A. excelsum by fruit character. When, however, it is compared with A. schultesii 

 AVoodson, similar in its heavily coriaceous leaves with whitened under side and 



