Monographs Details: Tocoyena brevifolia Steyerm.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Description:Latin Diagnosis - Arbor 15-metralis vel frutex; stipulis late deltoideis vel late ovatis longiacuminatis 3 mm longis extus stramineo-strigosis; foliis petiolatis, petiolis 6-7 mm longis dense hirtellis; laminis elliptieo-obovatis apice abrupte acuminatis, acumine 5-8 mm longo, basi conspicue angustatis 6.5-11 cm longis 3-6.5 cm latis, supra dense molliterque velutino-hirtellis, subtus molliter denseque pilis fuscis velutino-hirtellis, subtus costa media nervis lateralibusque magis densiuscule hirtellis; nervis lateralibus utroque latere 7-9 adscendentibus; inflorescentia terminali 7-10-flora pedunculata; pedunculis principalibus tribus 3-5 mm longis dense hirsutulis; pedicellis 1-2 mm longis hirsutulis; calyce hypanthioque cylindrico-turbinato 4-4.5 mm longa 2-3 m m lato abundante stramineo-hirsutulo 5-dentato, dentibus lineari-oblongis 0.3-0.6 mm longis; corolla in alabastro apice acuta hypocrateriformi, tubo 7-10.2 cm longo superne in faucem 5 mm longam 10 mm latam abrupte ampliato extus abundante hirtello, lobis 5 ovatis subacutis 2-2.2 cm longis 7-9 mm latis extus dimidia parte hirtello-pulverulenti dimidia parte glabrata, intus granulari-pulverulentibus, marginibus ciliatis; antheris 5 lineari-oblongis apice rotundatis 7 mm longis; stylo tubum corollae aequanti; stigmatibus spathulatis 5.5 mm longis.

Discussion:This taxon is related to T. neglecta N. E. Br., from which it differs in the longer corolla-tube, shorter corolla-lobes, shorter, more depressed calyx-lobes, relatively shorter and narrower leaves, and lower leaf-surface with prominent lateral nerves only evident and without the gray-pubescent reticulate network of tertiary venation so characteristic in T. neglecta and T. formosa (Cham. & Sch.) Schum. The collectors' notes give the color of the corolla as "cream" (Maguire, Wurdack & Bunting) or "amarillo fuerte" {Williams). The yellow color recorded is probably the result of ageing of the corolla, as noted by Foldats in his specimen of T. orinocensis {Foldats 3528), as changing from green in bud, white in anthesis, to finally yellow and yellow-orange in age.