Taxon Details: Miconia amilcariana Almeda & Dorr
Taxon Profile:
 | The Plant List |
 | International Plant Name Index |
 | Tropicos |
 | Catalogue of Life |
 | Global Biodiversity Information Facility |
 | JSTOR Types |
| JSTOR |
 | BHL |
 | Encyclopedia of Life |
 | WikiSpecies |
 | Google Scholar |
 | PubMed |
 | Morphbank |
 | IUCN |
 | National Center for Biotechnology Information |
 | Barcode of Life |
Multimedia:
Narratives:
Family:
Melastomataceae (Magnoliophyta)
Melastomataceae (Magnoliophyta)
Scientific Name:
Miconia amilcariana Almeda & Dorr
Miconia amilcariana Almeda & Dorr
Primary Citation:
Proc. Calif. Acad. Sci. ser. 4, 57: 549 (-555, fig. 1). 2006
Proc. Calif. Acad. Sci. ser. 4, 57: 549 (-555, fig. 1). 2006
Accepted Name:
This name is currently accepted.
This name is currently accepted.
Description:
Description Author and Date: F. Almeda, Jan 2012, based on Almeda, F. & L. J. Dorr. 2006. Proc. Calif. Acad. Sci., ser. 4, 57(19): 549, fig. 1.
Type: Venezuela. Trujillo: Mpio. Boconó, El Campamento-Pele Ojo, bajando hacia Quebrada Honda, 1900--2120 m, 9-16 July 1998, B. Stergios 17582 (holotype, PORT!; isotypes, CAS!, US!).
Description: Trees or understory shrubs (1.5)2--10 m tall with obtusely sulcate-quadrangular internodes that become terete with age. Uppermost cauline internodes, juvenile unexpanded leaves, and inflorescence rachis copiously but deciduously covered with a pale tan mixture of sessile-stellate and stalked-stellate and asperous-headed hairs. Leaves of a pair equal to subequal in size; petioles (1.7)2.5--7.5 cm long; blades 10.5--25 x 4--12 cm, elliptic, oblong-ovate to ovate, apex acuminate, base broadly rounded to nearly cordate, margin mostly entire but varying to crenate-serrulate or denticulate, 5-plinerved, the innermost pair of primary veins diverging from the median vein 2--10 mm above the blade base, adaxially ± glabrous at maturity, abaxially covered with a sparse to copious indument of sessile-stellate, stalked-stellate and asperous-headed hairs mostly on the primary and higher order veins with an inconspicuous scattering of minute orange-brown glands on the higher order veins and the actual blade surface. Inflorescence a terminal multiflowered panicle 6.5--12 cm long; bracteoles linear-subulate, 0.5 mm long and more or less 0.25 mm wide, glabrous, early deciduous and typically absent at anthesis. Flowers 5-merous and unisexual on pedicels 0.5 mm long, covered with a scattering of rusty-brown glands. Hypanthia (at anthesis) 1 mm long to the torus, glabrous or with a few minute rusty-brown glands. Calyx tube obsolete, the calyx lobes 0.25 x 0.25 mm, glabrous, bluntly rounded-triangular, exterior teeth 5, thickened and ± triangular or obconic, ca. 0.3 mm long but not projecting beyond the calyx lobes; torus glabrous on the abaxial side. Petals 1--1.1 x 0.5--0.6 mm, white, glabrous, obovate and ± concave, sometimes deeply notched or hooked apically in staminate flowers. Anthers white, isomorphic, cuneiform or obovoid, widest at the apex, 4-celled and 4-pored, the filaments 1.5--1.6 mm long, anthers 0.5 mm long and ca. 0.5 mm wide apically in staminate flowers, the filaments ca. 0.5 mm long, non-polleniferous and collapsed anthers ca. 0.4 mm long in pistillate flowers; connective prolonged 0.25 mm below the thecae in staminate flowers but neither elevated nor appendaged. Ovary (in fruit) 3/4 -inferior, 3-locular, the apex glabrous. Style straight, glabrous, 1--1.2 mm long, stigma peltate in pistillate flowers, these structures vestigial and barely evident in staminate flowers. Berry 2--2.5 x 2.5--3 mm, globose, green flushed with pink when immature becoming bluish or purple-pink at maturity. Seeds 0.5--0.75 mm long, ovoid to ovoid-pyramidate, the testa irregularly granulate.
Habitat and Distribution: This species grows in openings created by roads and other clearings in lower montane and montane (cloud) forest in the Cordillera de Trujillo, the northeastern-most range of the Venezuelan Andes at 1,700--2,550 m.
Phenology: Flowering and fruiting specimens have been collected in July and from September through January.
Etymology: This species is named for Amilcar Bencomo, Superintendent of Guaramacal National Park. With few tangible resources at his disposal, he has been fiercely protective of the park, an important refuge for Andean flora and fauna and an essential watershed for the people of Barinas, Portuguesa, and Trujillo states. Additionally, he has been an outstanding friend of science and has enthusiastically supported projects that contribute to expanding our knowledge of the natural history of Guaramacal.
Taxonomy and Systematics: Based on its obovoid-oblong anthers with a wide 4-pored apex and protruding septum, Miconia amilcariana is assigned to section Cremanium (D. Don) Naudin, the largest (with some 214 species) of the 10 currently recognized sections of Miconia. The distinctive features of M. amilcariana include its 5-merous unisexual flowers that are produced on different individuals (dioecy), anther pores that are essentially truncate or slightly inclined ventrally at the apex, peltate stigma on pistillate flowers, 3-locular ovary, 5--7-plinerved leaf blades, and indument on internodes and abaxial foliar surfaces that consists of a mixture of sessile- and stalked-stellate hairs, and asperous-headed hairs. Among the species of section Cremanium, Miconia amilcariana is most similar to M. laetevirens L. Uribe of Colombia and M. tabayensis Wurdack of Venezuela. The former differs from the new species in having hermaphroditic flowers, 3-nerved or shortly 3-plinerved leaf blades, elliptic to obovate-spatulate bracteoles that are persistent, and a clavate-truncate to subcapitate stigma. The anthers of both M. laetevirens and M. amilcariana are similar in shape and in being 4-loculed and 4-pored but the former differs in having the two dorsal anther sacs positioned above (superposed) the two ventral anther sacs with all the apical pores conspicuously inclined ventrally to give the overall anther a somewhat curved aspect (see Uribe Uribe, 1966). In M. amilcariana all the locules of each anther diverge from the same basal position to give the anther a straight posture. In overall morphological similarities, Miconia amilcariana appears to be most closely related to M. tabayensis, another dioecious species (Wurdack, 1973). The latter has leaf apices that are shortly obtuse-acuminate (vs. acuminate to long-acuminate), leaf bases that are obtuse to rounded (vs. broadly rounded to nearly cordate), and linear-oblong bracteoles that are 0.7--1 mm long (vs. linear-subulate bracteoles that are 0.5 mm long). The most striking feature of M. tabeyensis that readily distinguishes it from M. amilcariana is the indument on branchlet internodes, the inflorescence, and abaxial foliar surfaces. This indument, which is fairly dense and persistent, consists of inconspicuously septate simple hairs 0.5--1.2 mm long that are somewhat crisped and often forked or barbed distally. In M. amilcariana, the indument which can be sparse to copious but tardily deciduous consists of a mixture of sessile- and stalked-stellate hairs intermixed with asperous-headed hairs, all of which are prevailingly less than 0.5 mm in length. Each species also appears to occur in a different region of montane Venezuela. Miconia amilcariana is known from several collections made in the northeastern-most range of the Venezuelan Andes at 1,700--2,550 m. Miconia. tabayensis, also endemic to the Venezuelan Andes, has been collected only a few times above Mérida and in a region of the Cordillera de Mérida further south and west near Pueblo El Cobre at 2,300--2,800 m. The unisexual flowers of Miconia amilcariana consistently have vestigial organs of the other sex (Fig. 1F and 1H; Fig. 1C). This is common for dioecious species in families that are largely hermaphroditic like the Melastomataceae. Nectar is typically the attractant in female flowers of dioecious species (Proctor et al., 1996) but sterile anthers may be the prime attractant in female flowers where pollen is the prime reward. This is likely the case in small-flowered species like Miconia section Cremanium that are probably visited by generalist pollinators.
Description Author and Date: F. Almeda, Jan 2012, based on Almeda, F. & L. J. Dorr. 2006. Proc. Calif. Acad. Sci., ser. 4, 57(19): 549, fig. 1.
Type: Venezuela. Trujillo: Mpio. Boconó, El Campamento-Pele Ojo, bajando hacia Quebrada Honda, 1900--2120 m, 9-16 July 1998, B. Stergios 17582 (holotype, PORT!; isotypes, CAS!, US!).
Description: Trees or understory shrubs (1.5)2--10 m tall with obtusely sulcate-quadrangular internodes that become terete with age. Uppermost cauline internodes, juvenile unexpanded leaves, and inflorescence rachis copiously but deciduously covered with a pale tan mixture of sessile-stellate and stalked-stellate and asperous-headed hairs. Leaves of a pair equal to subequal in size; petioles (1.7)2.5--7.5 cm long; blades 10.5--25 x 4--12 cm, elliptic, oblong-ovate to ovate, apex acuminate, base broadly rounded to nearly cordate, margin mostly entire but varying to crenate-serrulate or denticulate, 5-plinerved, the innermost pair of primary veins diverging from the median vein 2--10 mm above the blade base, adaxially ± glabrous at maturity, abaxially covered with a sparse to copious indument of sessile-stellate, stalked-stellate and asperous-headed hairs mostly on the primary and higher order veins with an inconspicuous scattering of minute orange-brown glands on the higher order veins and the actual blade surface. Inflorescence a terminal multiflowered panicle 6.5--12 cm long; bracteoles linear-subulate, 0.5 mm long and more or less 0.25 mm wide, glabrous, early deciduous and typically absent at anthesis. Flowers 5-merous and unisexual on pedicels 0.5 mm long, covered with a scattering of rusty-brown glands. Hypanthia (at anthesis) 1 mm long to the torus, glabrous or with a few minute rusty-brown glands. Calyx tube obsolete, the calyx lobes 0.25 x 0.25 mm, glabrous, bluntly rounded-triangular, exterior teeth 5, thickened and ± triangular or obconic, ca. 0.3 mm long but not projecting beyond the calyx lobes; torus glabrous on the abaxial side. Petals 1--1.1 x 0.5--0.6 mm, white, glabrous, obovate and ± concave, sometimes deeply notched or hooked apically in staminate flowers. Anthers white, isomorphic, cuneiform or obovoid, widest at the apex, 4-celled and 4-pored, the filaments 1.5--1.6 mm long, anthers 0.5 mm long and ca. 0.5 mm wide apically in staminate flowers, the filaments ca. 0.5 mm long, non-polleniferous and collapsed anthers ca. 0.4 mm long in pistillate flowers; connective prolonged 0.25 mm below the thecae in staminate flowers but neither elevated nor appendaged. Ovary (in fruit) 3/4 -inferior, 3-locular, the apex glabrous. Style straight, glabrous, 1--1.2 mm long, stigma peltate in pistillate flowers, these structures vestigial and barely evident in staminate flowers. Berry 2--2.5 x 2.5--3 mm, globose, green flushed with pink when immature becoming bluish or purple-pink at maturity. Seeds 0.5--0.75 mm long, ovoid to ovoid-pyramidate, the testa irregularly granulate.
Habitat and Distribution: This species grows in openings created by roads and other clearings in lower montane and montane (cloud) forest in the Cordillera de Trujillo, the northeastern-most range of the Venezuelan Andes at 1,700--2,550 m.
Phenology: Flowering and fruiting specimens have been collected in July and from September through January.
Etymology: This species is named for Amilcar Bencomo, Superintendent of Guaramacal National Park. With few tangible resources at his disposal, he has been fiercely protective of the park, an important refuge for Andean flora and fauna and an essential watershed for the people of Barinas, Portuguesa, and Trujillo states. Additionally, he has been an outstanding friend of science and has enthusiastically supported projects that contribute to expanding our knowledge of the natural history of Guaramacal.
Taxonomy and Systematics: Based on its obovoid-oblong anthers with a wide 4-pored apex and protruding septum, Miconia amilcariana is assigned to section Cremanium (D. Don) Naudin, the largest (with some 214 species) of the 10 currently recognized sections of Miconia. The distinctive features of M. amilcariana include its 5-merous unisexual flowers that are produced on different individuals (dioecy), anther pores that are essentially truncate or slightly inclined ventrally at the apex, peltate stigma on pistillate flowers, 3-locular ovary, 5--7-plinerved leaf blades, and indument on internodes and abaxial foliar surfaces that consists of a mixture of sessile- and stalked-stellate hairs, and asperous-headed hairs. Among the species of section Cremanium, Miconia amilcariana is most similar to M. laetevirens L. Uribe of Colombia and M. tabayensis Wurdack of Venezuela. The former differs from the new species in having hermaphroditic flowers, 3-nerved or shortly 3-plinerved leaf blades, elliptic to obovate-spatulate bracteoles that are persistent, and a clavate-truncate to subcapitate stigma. The anthers of both M. laetevirens and M. amilcariana are similar in shape and in being 4-loculed and 4-pored but the former differs in having the two dorsal anther sacs positioned above (superposed) the two ventral anther sacs with all the apical pores conspicuously inclined ventrally to give the overall anther a somewhat curved aspect (see Uribe Uribe, 1966). In M. amilcariana all the locules of each anther diverge from the same basal position to give the anther a straight posture. In overall morphological similarities, Miconia amilcariana appears to be most closely related to M. tabayensis, another dioecious species (Wurdack, 1973). The latter has leaf apices that are shortly obtuse-acuminate (vs. acuminate to long-acuminate), leaf bases that are obtuse to rounded (vs. broadly rounded to nearly cordate), and linear-oblong bracteoles that are 0.7--1 mm long (vs. linear-subulate bracteoles that are 0.5 mm long). The most striking feature of M. tabeyensis that readily distinguishes it from M. amilcariana is the indument on branchlet internodes, the inflorescence, and abaxial foliar surfaces. This indument, which is fairly dense and persistent, consists of inconspicuously septate simple hairs 0.5--1.2 mm long that are somewhat crisped and often forked or barbed distally. In M. amilcariana, the indument which can be sparse to copious but tardily deciduous consists of a mixture of sessile- and stalked-stellate hairs intermixed with asperous-headed hairs, all of which are prevailingly less than 0.5 mm in length. Each species also appears to occur in a different region of montane Venezuela. Miconia amilcariana is known from several collections made in the northeastern-most range of the Venezuelan Andes at 1,700--2,550 m. Miconia. tabayensis, also endemic to the Venezuelan Andes, has been collected only a few times above Mérida and in a region of the Cordillera de Mérida further south and west near Pueblo El Cobre at 2,300--2,800 m. The unisexual flowers of Miconia amilcariana consistently have vestigial organs of the other sex (Fig. 1F and 1H; Fig. 1C). This is common for dioecious species in families that are largely hermaphroditic like the Melastomataceae. Nectar is typically the attractant in female flowers of dioecious species (Proctor et al., 1996) but sterile anthers may be the prime attractant in female flowers where pollen is the prime reward. This is likely the case in small-flowered species like Miconia section Cremanium that are probably visited by generalist pollinators.