Vriesea triligulata Mez
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Comments:
- Vriesea triligulata Mez is a good example of the problems faced by taxonomists. It was originally described in 1894 based on material from the Serra dos Orgaos collected by Glaziou. A close examination of the literature and the type material as well as of numerous herbarium collections resulting from field work in patches of Atlantic forest in the state of Rio de .Janeiro (see Costa, 1993), provided information which led to the true identity of this species.
Our results differ from those of Martinelli & Leme (1986): The species referred to by these authors as V. triligulata Mez is actually the new taxon V. fradensis. A detailed description of Vriesea triligulata is also given including the entire morphological variation observed in the specimens examined.
V. triligulata is a well-defined species, distinguished by the leaf sheaths which are nearly black on both sides and by the widely rounded leaf apex. The red inflorescence axis and yellow floral bracts plus the included stamens also serve to characterize this plant. It is found only in the section of the Serra do Mar that runs through Rio de Janeiro state and is a common forest species on the slopes of the Serra dos Orgaos as well as the Serra do Desengano in the northern part of the state.
This species is a sun-loving epiphyte, dwelling high in the canopy of the slope forests. In the more open, sunnier cloud forests, it lives on the ground as well as on lower tree branches. It is also found in some high altitude grasslands, where it is both terrestrial and rupicolous. These plants usually form clumps, and are only rarely seen as lone individuals.
The original description of V. triligulata (Mez, 1894) reports the presence of secund flowers, three liguliform appendages and six stamens (three included, three exserted). This was not confirmed, however, by an examination of the type material. The specimens studied by the author clearly show distichous flowers (not secund), three pairs of liguliform appendages and six included isodynamous stamens. The subsequent descriptions of Mez (1896, 1934-5) and Smith & Downs (1977) were based on the same type material, and no information is added nor is any of the original description altered. No illustration of the species is provided.
The above-mentioned authors do not agree as to the placement of this species within the genus. Mez (1894, 1896, 1934-5) included V. triligulata in the section Vriesea, while Smith & Downs ( 1977) placed i t in the section Xiphion (E. Morren) E. Morren ex Mez. Based on section descriptions, this species falls within the latter. However, its relationship to V. neoglutinosa Mez and related species suggests that it actually belongs in the section Vriesea, in spite of the included stamens. More natural infrageneric categories will only be established after more detailed examination of several groups of species, especially as regards floral morphology.
V. haematina is here considered to be a synonym of V. triligulata. The original description of this species was based on material in a rather advanced fruiting stage, but the examination of many specimens in various developmental stages showed that this material is also V. triligulata.
General notes
Since colonial times, the coastal ecosystems of eastern Brazil have been intensely impacted by man and only a small percentage of the original plant cover remains. Today, native vegetation is restricted to remote or legally protected areas, and as a result, many species are now found only in these locations.
Species diversity in the Bromeliaceae is greatest in Eastern Brazil (Smith, 1955), especially in the Atlantic forest, and the most important Brazilian state in terms of bromeliad diversity is Rio de Janeiro. Some 80 species of Vriesea are found in the Atlantic forest of this state (Fontoura et al., 1991).
Taxonomic studies of the Bromeliaceae must deal with three major problems: wide phenotypic plasticity of the taxons; lack of precision in available descriptions; and a small number of herbarium collections which do not represent the taxons adequately. Field studies, therefore, are the source of valuable inforrnation on many bromeliad groups, especially when they focus on remnant patches of native vegetation. —See Bromelia