Taxonomia e distribuição dos gêneros Euploca Nutt. e Heliotropium L. (Heliotropiaceae) para o Brasil

Abstract

This work deals of the taxonomic study of the genera Euploca Nutt. and Heliotropium L.(Heliotropiaceae) in Brazil. Comparative morphological studies were developed based on specimen from 70 herbaria, 58 from Brazil and 12 from abroad, also field works were developed in the States of Ceará, Rio Grande do Norte, Paraíba, Pernambuco and Bahia. The identifications were based on original descriptions, type and revisions, as well as local and regional floras. The descriptions were based exclusively on specimen collected in Brazil, following methods and terminologies of the classic taxonomic literature. Keys to the identification for genera and species, as well as illustrations of its vegetative, floral and fruit morphological features are presented. Comments on its taxonomic affinities based on its morphological features, besides flowering and fructification data or, when possible, common names also are provided. The patterns of geographical distribution of the species were established based exclusively on its studied specimen. In this work, 28 taxa were found; 17 species belongs to the genus Euploca and nine species and two subspecies belongs to the genus Heliotropium.The species of Euploca are: E. barbata (DC.) J.I.M. Melo & Semir, E. filiformis (Lehm.) J.I.M. Melo & Semir, E. fruticosa (L.) J.I.M. Melo & Semir, E. hassleriana (Chodat) J.I.M. Melo & Semir, E. humistrata (Cham.) J.I.M. Melo & Semir, E. krapovickasii J.I.M. Melo & Semir, E. lagoensis (Warm.) Diane & Hilger, E. ocellata (Cham.) J.I.M. Melo & Semir, E. pallescens (I.M. Johnst.) J.I.M. Melo & Semir, E.paradoxa (Mart.) J.I.M. Melo & Semir, E. parciflora (Mart.) J.I.M. Melo & Semir, E. polyphylla (Lehm.) J.I.M. Melo & Semir, E. pottii J.I.M. Melo & Semir, E. procumbens (Mill.) Diane & Hilger, E. rodaliae J.I.M. Melo & Semir, E. salicoides (Cham.) J.I.M. Melo & Semir and E. ternata (Vahl) J.I.M. Melo & Semir, three are news to the science, also being established twelve new combinations. In the genus Heliotropium, the following taxa are recognized: H. amplexicaule Vahl, H. angiospermum Murray, H. curassavicum L., H. curassavicum L. ssp. argentinum (I.M. Johnst.) J.I.M. Melo & Semir, H. elongatum (Lehm.) I.M. Johnst., H. elongatum ssp. burchellii (I.M. Johnst.) J.I.M. Melo & Semir, H. indicum L., H. leiocarpum Morong, H. nicotianaefolium Poir., H. phylicoides Cham. and H. transalpinum Vell., where the infraspecifs taxa represents new status. Four biogeography patterns general and their subpatterns were found. In Brazil, the diversity center of the species of Euploca comprises the Northeast (16), whilein Heliotropium the species are generally occurring in the South region (08). The Rio Grande do Sul State comprises the diversity center of Heliotropium, including the section Heliotrophytum G. Don, withtheir four species occurring in this State. The most important features to the recognizement of the genera were: presence/absence of bracts in the inflorescences, union grade of the anthers, number ofnutlets and embryo type. The species on both genera were distinguished mainly based on its vegetativeand blood features.