Revision and taxonomic position of the genus Euphronia Martius ex Martius & Zuccarini (Vochysiaceae)

Abstract

In this paper the generic name Euphronia Martius ex Martius & Zuccarini is recognized as the valid name for what has commonly been known as Lightia Rob, Schomburgk. The taxonomic position of the genus has been reconsidered, and Euphronia has been removed from the Trigoniaceae, and placed in the Vochysiaceae with which its affinities are closest. Only one species has been recognized, due to the high variability in size and shape of the leaves.

Flora of the Venezuelan Guayana-II

“…As indicated in the present key to the species and in comments under E. guianensis, E. hirtelloides is distinct in having a more elongated, many-flowered inflorescence; larger, more acutely tipped leaves; and the pubescence of pedicel and outer surface of calyx lobes of a different type. It should be noted here that the calyx of Euphronia is gamophyllous [Lleras (1976) mm longis, 1.2 mm latis; petalis suborbicularibus rotundatis 1.5 mm longis, 2 mm latis; fructu subgloboso vel ovoideo-subgloboso 7 mm longo, 7 mm lato; pyrenis 4-5 trigonis 5 mm longis, 3.5-5 mm latis, dorso 3-5-costatis.…”

“…& Yuncker, from which it differs in the glabrous stems and peduncles, more numerous lateral nerves, and floral bracts conspicuously fimbriate. In his publication on a revision and taxonomic position of the genus Euphronia, Lleras (1976) showed that the generic name Lightia must be replaced by the earlier Euphronia. Furthermore, he transferred the genus from the Trigoniaceae, where it had been placed previously, to the Vochysiaceae, the family he considered as showing the closest affinity.…”

“…Rocky savannas and open sandstone exposures of the eastern portion of Bolivar in the Venezuelan Guayana from the region of the Gran Sabana at Cerro Roraima westward to the summit of Cerro Guaiquinima, and in the adjacent Pakaraima Mountains of Guyana, at altitudes of 300-1,200 m, ascending to 1,600 m on the slopes of Ptari-tepui. [Cardona 2726 from the summit of Auyan-tepui at an altitude of 2,500 meters was cited as Euphronia hirtelloides by Lleras (1976). It is actually Myrtus alternifolia Gleason, as cited in Flora of Auyantepui (Steyermark, 1967).]…”

The Systematic Position of Euphronia, with Comments on the Position of Balanops: An Analysis Based on rbcL Sequence Data

“…1). Warming (1875) described two species, but Lleras (1976) concluded that there was too much variability to separate them and combined all collections into one species. Steyermark (1987), with access to more specimens, saw discontinuities in such features as the shape and indumentum of the calyx lobes, as well as range (Fig.…”

“…The taxonomic history of Euphronia was reviewed in detail by Lleras (1976) in his revision of the genus. First described in 1825 from incomplete material, it was placed in Kunth's Spireaceae, in which it remained until Warming (1875) put it in Trigoniaceae.…”