Tabebuia jackiana Ekman ex Urb.
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Authority
Gentry, Alwyn H. 1992. Bignoniaceae--part II (Tribe Tecomeae). Fl. Neotrop. Monogr. 25: 1-370. (Published by NYBG Press)
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Family
Bignoniaceae
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Scientific Name
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Type
Type. Cuba. Pinar del Río: Prope Mendoza, 150 m, Ekman 16736 (holotype, S; isotypes, B, MO, NY, S).
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Description
Species Description - Shrub or small dichotomously branched tree, the branchlets more or less terete, lepidote with small scales, especially densely at nodes, the leaves mostly clustered near branch apices. Leaves simple (one or two usually incompletely divided, 2-3-foliolate leaves occasionally also present), narrowly oblong, the apex obtuse to acutish and usually conspicuously apiculate, the base rounded to truncate or very slightly subcordate, 1.3-8 cm long, 0.7-2.4 cm wide, coriaceous, the margin slightly erose, lepidote with small scales above, below densely lepidote with individually poorly defined scales over surface and also with scattered larger conspicuous lepidote scales, gray to olive gray above, the secondary veins and tertiary venation paler than surface and prominulous below, surface rough to touch above, the midvein impressed above, lateral leaflets rare, when present sessile, asymmetric, and sometimes not completely separated from central leaflet; petioles 0.2-1.0 cm long. Inflorescence of one or two flowers at a branch apex, the pedicel lepidote, 1-1.5 cm long, ebracteolate or with a pair of inconspicuous bracteole scars near base. Flowers (not dissected) with the calyx campanulate, irregularly 2-3-lobed, 7-13 mm long, 4-6 mm wide, drying dark with grayish lepidote scales; corolla white (fide Urban), infundibuliform, 3-4.5 cm long, 0.7-1.5 cm wide at mouth of tube, the tube 2.5-3.5 cm long, the lobes 0.5-1 cm long, ciliate on lobes and sparsely puberulous with short trichomes on inner surface of lobes. Fruits unknown.
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Discussion
This species is known only from a few collections from near the western tip of Cuba. Although described by Urban as mostly unifoliolate, rarely 2-3-foliolate, Alain (1957) keys it out as having leaves mostly 3-foliolate with a parenthetical note that some leaves of this species are even 4-foliolate. Of the material I have seen, one isotype (NY) has one three-foliolate leaf, a second isotype has single 2-foliolate and three-foliolate leaves, and the holotype has one 2-foliolate and two 3-foliolate leaves; all other leaves are simple. The paratypes (Ekman 18726) include branchlets with uniformly simple leaves and others with a mixture of simple and 3-foliolate leaves or uniformly 2- and 3-foliolate leaves, the latter obviously in juvenile condition. It is possible that the two shoots with compound leaves, which also have a different smoother bark and large elliptic leaflets (to 4 x 2 cm with a 1.5 cm long petiole) represent a juvenile growth form, introgression from a sympatric species, or perhaps a mixed collection. The great majority of leaves seem to be simple rather than unifoliolate since there is no evident articulation and they fall with the petiole attached. The species is closest to uniformly simple-leaved T. myrtifolia, forming the westernmost and physiognomically most mesic element in the cline in leaf size, shape, and degree of scaling discussed under that species. It is also very close to T. glaucescens of Las Villas Province which differs in being largely 3-foliolate; the unifoliolate leaves of T. glaucescens are more obovate, cuneately narrowed toward the base and jointed at the petiole apex, the blade mostly falling detached from the petiole. A note on one of the collections indicates that T. calcicola, which has similar leaflets but consistently compound leaves, is common in the same area and it is possible that T. jackiana represents hybridization between T. calcicola and a simple-leaved species like T. myrtifolia.
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Objects
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Distribution
Known only from limestone rocks at low altitude in westernmost Cuba; below 200 m elevation.
Cuba South America| Piñar del Río Cuba South America|