The Demography of Miconia prasina (Melastomataceae) During Secondary Succession in Puerto Rico1

Miconia prasina (Melastomataceae) is an important colonizing species during early stages of secondary succession in Puerto Rico but its abundance declines with increasing stand age. We studied its demography for 2 yr (1995–1997) in three populations across a pasture to forest chronosequence (1‐, 12‐, and 25‐yr old) and in one population in a hurricane‐disturbed older forest (>60‐yr old). Vegetative growth was positive in the two young sites, but negative in the two older sites. The highest percentage of plants that flowered occurred in the two younger sites but highest seed production occurred in the 25‐yr‐old site. Although seed germination occurred in the two older sites, no seedlings established. Vegetative reproduction (root sprouts) was found in all sites, with most sprouts occurring in young sites. The 2 yr of census data were used to construct stage‐based transition matrices. In the two young sites, the average population growth rate was positive (λ > 1), while average population growth was negative in the two older sites (λ < 1). Elasticity, a measure of the effects of proportional changes in life‐history transitions to the long‐term population growth rate, varied across both stages and sites. Elasticity shifted from large plants in young sites to small plants in older sites. Across all sites, elasticities related to survival were more important than those of growth or vegetative reproduction. The demographic analysis supported the previous observations of changes in the density of M. prasina based on the chronosequence and also suggests that establishment via seeds must occur prior to abandonment in active pastures.     

Three new mesoamerican species of Miconia (Melastomataceae)

Miconia centrosperma andM. santaritensis from Panama, andM. stevensiana from Honduras, Nicaragua and Costa Rica, are described, illustrated, and compared with their presumed relatives.     

Tahiti's native flora endangered by the invasion of Miconia calvescens DC. (Melastomataceae)

Abstract. The native flora of tropical oceanic islands is known to be particularly susceptible both to displacement and extinction, following the invasion of alien organisms. Miconia calvescens DC. (Melastomataceae), first introduced to Tahiti (French Polynesia, South Pacific Ocean) in 1937 as an ornamental plant, now covers over two-thirds of the Island. As it forms dense monotypic stands which have progressively overwhelmed the native forests, this plant pest is a direct threat to the rich Tahitian indigenous flora. Between 40 and 50 species of the 107 species endemic to Tahiti are thought to be on the verge of extinction. M. calvescens was finally declared a'noxious species in French Polynesia'in 1990. Without efficient control efforts and effective endangered plant conservation and protection legislation, M. calvescens could cause Tahiti and all the high islands of French Polynesia to become ecological deserts.     

Miconia galeiformis and Miconia neei (Miconieae: Melastomataceae), two new species from Bolivia

Two new species of Miconia from Bolivia are described: Miconia galeiformis and Miconia neei. Both species occur in Andean montane forests. Miconia galeiformis (sect. Chaenopleura) is distinctive within Miconia due to the presence of setose stems, petioles and abaxial leaf surface, and a large, globose stigma. Miconia neei bears unisexual flowers, and can be distinguished from similar species of Miconia sect. Cremanium in Bolivia based on the furfuraceous stems and young nodes, in addition to serrulate leaf margins. The documentation of dioecy in Miconia neei and the occasional occurrence of unisexual flowers in Miconia galeiformis adds to our burgeoning understanding of complex breeding systems within Miconia.     

A new species of Miconia (Melastomataceae, Miconieae) from northeastern Brazil

Miconia caiuia occurs only in the highly endangered submontane moist forests in the states of Alagoas, Pernambuco, and northern Bahia, Brazil. It belongs to Miconia section Miconia subsection Secundiflorae. This new species can be distinguished from other species in this subsection by the lepidote-stellate trichomes on young branches, petioles, inflorescences and hypanthia, leaves with suprabasal nerves and wrinkled/auriculate bases, abaxial leaf surfaces with only sparse trichomes, a 5-locular ovary, and large mature fruits (10–13?×?12–15 mm) with up to 15 seeds, which are 2.5–3.5 mm long.     

Miconia zanonii (Melastomataceae: Miconieae), a new species from Hispaniola

Miconia zanonii, which occurs in broad-leaved cloud forests at four localities in the Cordillera Central of the Dominican Republic, is described and illustrated. It is compared withM. krugii andM. samanensis, two probably close relatives withinMiconia sect.Chaenopleura.     

Isolation and characterization of polymorphic microsatellite markers from the velvet tree, Miconia calvescens DC. (Melastomataceae)

Nine polymorphic microsatellite loci were isolated and characterized from the invasive velvet tree (Miconia calvescens DC.), a serious forest invader in tropical Pacific oceanic islands. These loci provided markers with polymorphism of three to 10 alleles per locus within 95 individuals. The expected and observed heterozygosities ranged from 0.0367 to 0.5053 and from 0.0370 to 0.2473, respectively. These markers should be useful to study dispersal and the invasion genetics of the velvet tree.     

Miconia becqueri,a new species of Miconia (Melastomataceae) with strongly four-lobed ovaries from the Sierra Maestra,Cuba

A new species of Miconia belonging to a clade diagnosed by strongly four-lobed ovaries/hypanthia and elongated calyx teeth flattened parallel to the floral radii, i.e., the Calycogonium hispidulum complex, endemic to the Sierra Maestra of eastern Cuba, is described, illustrated, and compared with related Cuban species. The discovery of Miconia becqueri brings to 15 the number of recognized species of this complex, seven of which occur in Cuba (if Clidemia barbeyana is conspecific with C. wrightii).     

Biology, herbivory, and host specificity of Antiblemma leucocyma (Lepidoptera: Noctuidae) on Miconia calvescens DC. (Melastomataceae) in Brazil

Miconia calvescens DC. (Melastomataceae) is an invasive tree considered one of the greatest threats to natural ecosystems of Hawaii and other Pacific islands. The potential for using the defoliator Antiblemma leucocyma (Lepidoptera: Noctuidae) as a biological control agent of M. calvescens was evaluated in the native habitat of the insect in Brazil. Impact assessment in the field showed that 37.2% of leaves presented damage by A. leucocyma, and among damaged leaves, 1.5-51.9% of the leaf area (16.3% on average) was affected. Damage was found in young to fully expanded leaves (28-915 cm² in area). Individual A. leucocyma developing as third through sixth instars in the laboratory consumed an average of 1348 cm² of M. calvescens leaf material in about 11 days. Populations of A. leucocyma in the field were heavily impacted (up to 83% parasitism) by a braconid parasitoid. Observations in the field and single- and two-host choice tests in the laboratory indicated that A. leucocyma has a narrow host range restricted to M. calvescens. Usefulness of this herbivore for biological control in Hawaii appears low, however, because of its probable susceptibility to generalist parasitoids.     

Two new species of Huberia (Melastomataceae: Merianieae) from Brazil

Two new Brazilian species of the genusHuberia,H. carvalhoi andH. consimilis, are described, discussed, and illustrated.Huberia carvalhoi is endemic to Bahia;H. consimilis has a wider distribution, with disjunct populations in Pernambuco, Bahia, and Rio de Janeiro. A key is provided to the three Bahia taxa with some comments on the taxonomic affinities of the two new species.     

Two new species in Memecylon (Melastomataceae) from India

Two new species in Memecylon, M. kollimalayana and M. bremeri , of Melastomataceae are described here with illustrations from the Kollihills of Salem District in Tamil Nadu, India.     

Observations on the big bang flowering of Miconia minutiflora (Melastomataceae)

Trees ofMiconia minutiflora produced abundant flowers for only one to three days during mid-April 1983 in the vicinity of Saül, French Guiana. They attracted large numbers of at least 14 species of bees that collected nectar or pollen or both. Nectar production is uncommon in the Melastomataceae and not previously reported forMiconia. Peak bee activity at the trees was in the morning and by afternoon most visits were limited to those bees in search of remnant pollen, especially species ofTrigona. As has been shown for other neotropical plants, heavy rains may trigger flowering in this species. It is suggested that the flowering system ofM. minutiflora promotes outcrossing because of interactions among the numerous species of bees visiting the trees and because of inter-individual variation in nectar and pollen availability. Therefore, bees may fly to other trees instead of becoming satiated with nectar or pollen from a single tree.     

Taxonomic studies in the Miconieae (Melastomataceae). VI. Miconia santanana,a new species from Hispaniola

Miconia santanana, which occurs in broad-leaved forests along streams of pineland habitats in the Cordillera Central of the Dominican Republic, is described and illustrated. It is compared withM. ferruginea andM. adenocalyx, two presumed close relatives withinMiconia sect.Chaenopleura. Eco-geographic characterizations and a key are presented for these three species.     

Two new species of Charianthus (Melastomataceae: Miconieae) from the Lesser Antilles

In the course of a phylogenetic analysis and systematic revision ofCharianthus, it was discovered thatC. purpureus, as traditionally circumscribed, is polyphyletic, consisting of three morphologically diagnosable entities. Thus two new species,Charianthus dominicensis andC. grenadensis, are described and illustrated. Each is endemic to the Lesser Antillean island for which it is named—Dominica and Grenada, respectively.Charianthus, the only vascular plant genus endemic to the Lesser Antilles, comprises six species of nectariferous, hummingbird-pollinated shrubs and small trees.     

Two new species ofPhyllagathis related toP. tuberculata (Melastomataceae) from Peninsular Malaysia

Phyllagathis tuberculata King and two closely allied new species,P. magnifica A. Weber andP. stonei A. Weber, are described and illustrated. Within the genus, these species form a distinct and isolated group which is restricted to Peninsular Malaysia.P. tuberculata occurs in Perak (probably confined to G. Bujang Melaka),P. magnifica andP. stonei are found in the mountains on the Pahang/Selangor border (Genting Highlands, Gombak valley). The distinctive characters of the three species are listed and some general information relating to inflorescence morphology, tubercle anatomy, fruit structure and seed dispersal is provided.     

Observations on the Reproductive Biology of Miconia calvescens DC (Melastomataceae), an Alien Invasive Tree on the Island of Tahiti (South Pacific Ocean)1

Miconia calvescens DC (Melastomataceae) is a dominant invasive species in the tropical oceanic island of Tahiti (French Polynesia, South Pacific Ocean), where it was introduced as an ornamental plant. Whereas this small tree is sparse in its native range of Central America, it has spread in Tahiti into a wide variety of habitats including native wet forests. The remarkable success of this invasion is due in great part to prolific reproduction: a mature tree can bear up to 220 inflorescences with an average of 1330 flowers/inflorescence, 208 fruits/infructescence and 195 seeds/fruit. Two and a half years of phenological observations in a highly invaded site indicated that three major peaks of flowering occur/year over brief periods: flower anthesis lasted a few days and pollen grain germination suggested a short stigmatic receptivity of only a few hours; no pollinators were observed foraging on flowers during our survey; the production of fruits containing viable seeds in bagged inflorescences showed that self-fertilization can occur; pollen-ovule ratio (log P/O = 2.68) suggested facultative xenogamy; bagged isolated flowers to test for autogamy and style cutting to learn whether apomixis occured or not were not conclusive. The flowering phenology and the breeding system of M. calvescens enable this plant to build up rapidly successful populations from even a single propagule on the island of Tahiti and on other sites of introduction. The vegetation structure of Polynesian native forests compared to Neotropical rain forests probably plays an important role in determining the reproductive success of M. calvescens and could provide a complementary explanation of the biological invasion processes in tropical oceanic islands.     

Two new species of myrmecophytic Tococa (Melastomataceae) with unusually large floral bracts

Two new species ofTococa with large bracts and ant domatia are described.Tococa leticiana has caducous acuminate floral bracts that enclose the young inflorescence and is known only from Leticia, Colombia.Tococa costoides has persistent broadly ovate floral bracts and is known from Amazonas State in Brazil.     

Two new species of Microlicia D.Don (Melastomataceae) from campos rupestres in eastern Brazil

Two new species of Microlicia (Melastomataceae) endemic to campos rupestres in Serra do Cipó, Minas Gerais, Brazil, are described, illustrated and compared with their putative relatives. Microlicia rugosa sp. nov. is similar to M. minutiflora and M. martiana by having fastigiate branches, ascending, lanceolate or oblanceolate leaves with obtuse apex, attenuate base and entire margin, flower with short pedicels (1?2 mm long), magenta petals, and dimorphic stamens. Microlicia rugosa is further characterized by wrinkled surface of hypanthium and sepals, and both leaf surfaces with distinct depressions, which sometimes contain short‐stalked glandular trichomes. Microlicia viscida sp. nov. is similar to M. martiana, M. furnensis and M. rugosa mainly by having fastigiate branches, terete stems without leaves at the base and the bark gradually peeling to reveal the underlying brownish wood and leaves with similar size and shape. Microlicia viscida is characterized by a conspicuous secretion covering branches, leaves, hypanthium and sepals, giving a smooth and bright appearance. The leaf anatomy of both new species is briefly described. Microlicia rugosa and M. viscida are assessed as ‘Endangered’ and ‘Critically Endangered’ respectively, due to its limited extent of occurrence and area of occupancy, according to the IUCN categories and criteria.