Morphology, leaf anatomy, and phytochemistr y of Eriope Humb. & Bonpl. ex Benth. species (Lamiaceae) occurring in Goiás

Abstract

Eriope is a genus of the family Lamiaceae, subfamily Nepetoideae, tribe Ocimae, and subtribe Hyptidinae and has approximately 30 species, among which 20 are restricted to the campos rupestres of Brazil. In the state of Goiás, Chapada dos Veadeiros, Serra de Caldas, Serra dos Cristais, Serra Dourada, and Serra dos Pireneus are typical rupestre environments. In addition to these places, we found specimens of Eriope in the municipalities of Colinas do Sul, Goiânia, Mineiros, Planaltina de Goiás, Uruaçu, and Vianópolis, all of them in the Cerrado biome. The geographic locations were registered using GPS and we identified fertile individuals of each taxon, which were deposited in the UFG herbarium. For the anatomical analyses, we fixed petiole and leaf blade fragments in FAA 70% for 24 h, which were posteriorly stored in ethanol 70%. The histological plates were prepared using the normal plant microtechniques. For the chemical analyses of essential oils and phytochemical screening of leaves we collected branches, which were stored at ambient temperature for 4 weeks in perforated paper bags. The dried leaves were grounded and we obtained approximately 30 g of powder for each taxon. The essential oils were extracted by hydrodestillation in a modified Clevenger-type apparatus and, after that, analyzed using gas chromatography coupled with mass spectroscopy (GC-MS). We studied eight taxa: Eriope complicata Mart. ex Benth., Eriope crassipes Benth. subsp. crassipes var. acutifolia Benth., Eriope crassipes Benth. subsp. crassipes var. macrophylla Benth.,  Eriope crassipes Benth. subsp. cristalinae Harley, Eriope foetida A. St. Hil. ex Benth., Eriope velutina Epling and two taxa collected in the municipalities of Alto Paraíso de Goiás and Cristalina, Goiás, described as new species. The subspecies Eriope crassipes Benth. subsp. cristalinae Harley presents distinct morphologic and anatomical characteristics within the group; thus we suggest to maintain the specific status Eriope cristalinae (Harley) C. T. Rizzini and use Eriope crassipes Benth. subsp. cristalinae Harley as a synonym. Characteristics such as dense hairiness, thick cuticle, sinuous anticlinal walls of epidermal cells, hypodermis, amphistomatic leaves, isobilateral mesophyll, broad group of sclerenchymatic cells external to the phloem, and presence of sclereids allowed us to conclude that the species studied are xeromorphic. We created identification keys using morphologic and anatomical data for the taxa under study. The species present anthraquinone flavonic and saponin heterosides, triterpenes and fenolic compounds. As to the essential oils, among the 58 identified compounds, ?-copaen, aromadendrene, and ?-copaen-4?-ol were found in all the taxa.