 |
| Miconia dianae R.Goldenb., Michelang. & Amorim, in Goldenberg, Michelangeli, Ziemmer et Amorim, 2023. |
Abstract
Miconia dianae is a new species described from four specimens collected in semideciduous forests in the municipality of Ribeirão do Largo, in the state of Bahia, Brazil. According to current data and based on IUCN criteria, this species should be qualified as “data deficient”, but we note that it should be actually considered as critically endangered, since the known habitat of M. dianae is reduced and subject of constant disturbance, which may perhaps lead to its extinction. The new species can be recognized by the inflorescences of pedunculate triads or seldom pauciflorous racemes with up to five flowers, these on a short pedicel topping an anthopodium 3–8 mm long, early caducous, filiform bracteoles, 5-merous flowers, terete hypanthia with verrucose projections on the abaxial surface, the calyx incompletely closed in bud, rupturing at anthesis in irregular lobes, white stamens with a dorso-basal hump and glandular trichomes on the connective, and a 3-locular, superior ovary with sparse glandular trichomes. The granulose surfaces of stems, leaves, inflorescences and hypanthia in dried specimens are caused by large druses, sometimes measuring half the thickness of the leaf mesophyll, that project themselves into hemispheric domes when the leaves are dried. The verrucose projections on the hypanthium develop from successive divisions of the ground tissue inside it. We were not able to explain its function, since they are not formed by crystals, nor seem to develop as pathogen or animal-induced galls, neither seem to store phenolic compounds nor starch. Since they fade away while the fruits ripen, they probably do not have any function related to dispersal either.
Keywords: Plant anatomy, Semideciduous forests, South America, Taxonomy, Verrucose projections
 |
| General morphology of Miconia dianae. a Branch with inflorescences, with the detail of the abaxial surface of the leaf base. b Details of two inflorescences. c Flower bud in pre-anthesis, lateral view, with the detail of the sepals. d Flower at anthesis, lateral view, with the detail of one bracteole. e Petal, adaxial view. f Old flower (post-anthesis), lateral view. g Flower at anthesis, longitudinal section, with the detail of the torus at the apex of the hypanthium, and bases of the petals. h Stamens in lateral view, antesepalous (left) and antepetalous (right), with the detail of the filament apex and anther/connective base of the antesepalous stamen. a–h From the holotype, Amorim et al. 11,810 (UPCB). Drawings by Diana Carneiro |
 |
| Miconia dianae in the field. a Vegetative and flowering branches. b Leaf margin, adaxial surface. c Leaf margin, abaxial surface. d Inflorescence, with a detail of the external portion of the sepal; e Leaf base, adaxial surface. f Flower, apical/lateral view, showing the zygomorphic arrangement of the stamens and style; the red arrow indicates one of the longer, antesepalous stamens, and the blue one indicates a glandular trichome on a lateral position of the connective in one of the shorter, antepetalous stamens. g Hypanthium lateral view, showing the verrucose projections and the minute, stellate trichomes. h Flower, lateral view; the yellow arrow indicates the single, stout glandular trichome bending downward on the connective of an antesepalous stamen, and the red one indicates the connective’s dorsal hump on the same stamen. From Amorim et al. 11,810 (UPCB). Photos by Y. Gouvêa |
Miconia dianae R.Goldenb., Michelang. & Amorim, sp. nov.
Etymology: This epithet honors Prof. Diana Carneiro (1947–; www.dianacarneiro.com), a botanical artist born in the municipality of Guanambi (Bahia, Brazil) and now living and actively working at Curitiba (Paraná, Brazil). During an extensive career teaching scientific art, and illustrating hundreds of botanical publications, she has been producing the finest botanical art, always combining an amazing technical precision with her beautifully drawn lines and competent composition. After preparing 63 botanical illustrations for regularly published scientific papers only in Melastomataceae, from which 43 are new species from 14 genera, she came to draw details of melastomes from amazing 25 Brazilian genera. We are sure that very few botanists in the world have analyzed flowers of species from this number of genera in Melastomataceae; we may, therefore, recognize and declare Diana Carneiro as a melastome specialist, such as we are.
Renato Goldenberg, Fabián A. Michelangeli, Juliana K. Ziemmer and André M. Amorim. 2023. Miconia dianae (Melastomataceae), A New Species from Bahia (Brazil) with Notes on leaf and hypanthium surfaces. Brazilian Journal of Botany. DOI: 10.1007/s40415-023-00932-6
