Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.
Apocynaceae
Maguire & Wurdack 35663, Rio Guainia, Amazonas, along Cano Pimichin below Pimiehin, elev. 125-135 m, April 14, 1953, slender tree 10 m, fruit brown.
Only a fruiting specimen is available. The matured follicle is oblong-obovate and much smaller than has been described for either this species or A. sprnceanum Benth. ex Muell-Arg., about half the size. 4 cm long, 2 cm wide. The stipe is a little over 1 cm long. The seeds are numerous, oblong to triangular, narrowly papery-winged, 2-2.5 cm long, 1.3-1.7 cm wide; cotyledons orbicular, about 1.3 cm wide, the sinus closed, the radicle 3 mm long, not surpassing the lobes of the cotyledons. The plant is named A. album rather than A. spruceanum because the petiole is longer than that of the latter, 1.5-2.5 cm long, and the venation on the underside is slightly more expressed. Woodson (Ann. Missouri Bot. Gard. 38: 196. 1951) hypothesizes possible hybridization to account for variability in A. album.