Tabebuia myrtifolia var. petrophila (Greenm.) A.H.Gentry
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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
HT: ; ; Cuba: Matanzas: prope Matanzas, Rugel 863 bis. (GOET; IT: HAC(as 612), K(s.n.), NY(as 612c & 863))
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Synonyms
Tabebuia petrophila Greenm., Tabebuia anafensis Urb., Tabebuia anafensis subsp. munizii Borhidi
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Description
Variety Description - Shrub or small tree to 5 m tall, usually densely branched, the branchlets terete, sometimes with spinescent tips. Leaves simple (rarely irregularly 2-foliolate in part), mostly oblong to oblong-obovate, rounded or retuse at apex, sometimes apiculate, rounded to cuneate (to subcordate in western part of range) at base, 0.5-3.5(-5) cm long, 0.2-0.9(-1.6) cm wide, coriaceous, densely lepidote above and below, concolorous, the upper and lower surfaces grayish olive, petioles 14 mm long. Inflorescences of one or two flowers from the branch apices, the pedicels 2-6(-10) mm long, lepidote. Flowers with the calyx campanulate, irregularly shortly bilabiate, to 3-4-labiate, densely grayish lepidote, 6-8(-10) mm long, 3-5 mm wide; corolla light magenta to whitish, tubular-infundibuliform, exactly as in T. microphylla. Fruit linear-cylindric, 6-10 cm long, 4-5 mm wide, lepidote, subtended by the persistent calyx; seeds thin, bialate, 2-3 mm long, 10-15 mm wide, the hyaline-membranaceous wings sharply demarcated from the seed body.
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Discussion
There seems to be a complete clinal intergradation between T. myrtifolia, T. petrophila, and T. anafensis. Typical T. myrtifolia, which occurs mostly in Oriente, has the leaves discolorous and so densely lepidote beneath that the surface is invisible. Typical T. petrophila has the leaves concolorous and less densely lepidote with the lower surface clearly visible between the scales; this is the form commonly found in central Cuba. Tabebuia anafensis occurs in western Cuba in Habana and Pinar del Río Provinces and has the leaves even less densely lepidote. Tabebuia jackiana of Pinar del Río represents a large-leaved, only slightly lepidote, extreme of this same cline, but may be distinct enough for specific recognition. In Cienfuegos and Matanzas Provinces forms with both densely and sparsely lepidote leaves occur together, sometimes even in the same gathering, suggesting that the variation is varietal at best. Alain (1957) recognized several additional segregates: uniformly shorter leaved forms as T. mogotensis (leaves densely whitish lepidote below) and T. truncata (leaves up to 2 cm long and gray below), longer-leaved forms as T. saxicola (leaves 2-4 cm long and densely white lepidote below). None of these segregates seems worthy of even varietal recognition. Borhidi & Muñiz (1973) recognized this pattern but accorded the two extremes specific rank and the intermediates subspecific rank: from west to east, T. anafensis ssp. anafensis, T. anafensis ssp. munizii, and T. petrophila, the latter incorrectly substituted for T. myrtifolia. Without extensive field work, it is not at all clear that lumping this complex together as a single variable species is the best procedure. At any rate, any segregate taxa recognized must be based entirely on the vegetative differences, since the differences in fruit length and corolla and calyx size noted by Borhidi are correlated neither with geography nor the vegetative characters and are not of taxonomic significance. It is not absolutely certain that T. myrtifolia itself is adequately differentiated from T. microphylla with shorter leaves and T. densifolia with elliptic apiculate leaves. In this light it is interesting that the only Haitian collection with long enough leaves to be classified as T. myrtifolia has the concolorous leaf undersurface of the western Cuban populations of var. petrophila whereas the Beata Island, Dominican Republic material here tenatively referred to T. myrtifolia var. myrtifolia has some branches with leaves indistinguishable from T. microphylla. This geographic pattern might suggest that both T. myrtifolia and T. myrtifolia var. petrophila represent no more than ecotypic differentiation of T. microphylla. Alternatively it is possible that the Hispaniolan collections represent hybridization of T. microphylla with T. obovata and T. densifolia, respectively.
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Objects
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Distribution
Central and western Cuba, mostly on limestone, also perhaps in central Haiti.
Cuba South America| Cienfuegos Cuba South America| La Habana Cuba South America| Matanzas Cuba South America| Piñar del Río Cuba South America| Haiti South America|