Monographs Details: Tabebuia x del-riscoi Borhidi
Authority: Gentry, Alwyn H. 1992. Bignoniaceae--part II (Tribe Tecomeae). Fl. Neotrop. Monogr. 25: 1-370. (Published by NYBG Press)
Family:Bignoniaceae
Synonyms:Tabebuia x rosariensis Borhidi
Description:Species Description - Small tree to 6-8 m tall, the leaves somewhat clustered toward branch apices, the older branchlets subterete with raised leaf scars. Leaves (in part from Borhidi, 1980) 1-3-foliolate, ovate to obovate (leaflets of trifoliolate leaves obovate), the apex obtuse to subacuminate, apiculate, the base rounded or obtuse, 4.5-7 cm long, 2.5-4 cm wide, coriaceous to thick coriaceous, the margin entire or subcrenulate, densely lepidote, concolorous; petioles 0.7-2.5 cm long, the terminal petiolule (when present) to 1 cm long. Inflorescence a single terminal flower, the pedicels to 1.5 cm long, lepidote. Flower with the corolla white, tubular-infundibuliform, 4-5 cm long. Fruit linear-cylindric, ca. 15 cm long, lepidote; seeds thin, bialate, 5 mm long, 25-30 mm wide, the wings hyaline-membranaceous.

Discussion:This is almost certainly a hybrid between T. lepidophylla and T. heterophylla (or one of the compound-leaved species closely related to the latter). Characters cited by Borhidi as distinguishing T. lepidophylla from T. del-riscoi include uniformly simple leaves with narrower bases, a more densely lepidote undersurface, and revolute margin, larger 5-lobed calyx with acute lobes, magenta corolla color, and shorter capsule. The purported flower and fruit characters are of little or no taxonomic value since T. lepidophylla can have either white (usually) or pink flowers and has mostly 2-3-labiate calyces as small as 10 mm long, and fruits as long as 13 cm. Since the in part 3-foliolate leaves of this species give it a rather different aspect than T. lepidophylla and cause it to key out in a different part of the key, I have treated it as a species despite its probable hybrid status. Apparently it forms part of a hybrid complex since an additional intermediate between T. del-riscoi and T. angustata was encountered in the same place and designated by its author as a hybrid. Moreover, all of the distinguishing characteristics of T. del-riscoi are exactly those that would be expected of a hybrid between T. lepidophylla and T. heterophylla.
Distribution:Cuba South America| Piñar del Río Cuba South America|