A new species of Microlicia (Melastomataceae) from Brazil

A new species of the genusMicrolicia,M. flava, from the highland “campo rupestre” vegetation of Serra da Canastra National Park, São Roque de Minas, Minas Gerais, Brazil, is described and illustrated.     

Four new species of Trembleya (Melastomataceae: Microlicieae) from Serra do Cabral, Minas Gerais, Brazil

Nine species of the Brazilian endemic genus, Trembleya, were collected during a floristic survey of the tribe Microlicieae on Serra do Cabral, an isolated mountain range in north-central Minas Gerais State, Brazil. Four of these are newly described and illustrated here: Trembleya inversa, T. purpurascens, T. rubra, and T. serrulata, represent new taxa for the genus. These new species appear to be endemic to Serra do Cabral where they occur in campo rupestre and cerrado vegetation. Serra do Cabral has the distinction of harboring more species of Trembleya than any other mountain range 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.     

The best of both worlds: Apomixis and sexuality co-occur in species of Microlicia,Melastomataceae

Apomixis, the asexual formation of embryos and seeds, occurs in approximately 18% of angiosperm families. Melastomataceae exhibits a remarkable number of apomictic species, distributed among different tribes. This mode of reproduction has been elucidated in Miconieae, but remains unclarified for other groups, such as Microlicieae. Although apomixis has been previously described for Microlicieae species, the cytological basis for this phenomenon is entirely unknown in this group. Thus, populations of Microlicia fasciculata and M. polystemma were used in order to (a) investigate the presence of autonomous apomixis; (b) verify if this mode of reproduction leads to polyembryony; and (c) investigate whether apomixis may occur in parallel with the sexual process. We tested these species for autonomous fruit set and polyembryony, and pollen viability, and analyzed pollen tube growth. Anatomical techniques were used to elucidate the micro- and megasporogenesis and gametogenesis. The species showed autonomous fruit and seed formation and exhibited polyembryony. Apospory and adventitious embryony were the developmental mechanisms of apomixis in M. fasciculata and M. polystemma, respectively. Both species exhibited low pollen viability. However, some viable pollen, reduced embryo sac formation, natural pollination and pollen tube growth enable sexual reproduction and characterize these species as facultative apomicts. The independence of pollinators for fruit set, uniparental reproduction and the possibility of sexual reproduction, confer reproductive assurance and flexibility, bringing together advantages of sexual and asexual reproduction. In this sense, apomixis may have played an important role in the evolution and diversification of Microlicia, a widely distributed genus in the Brazilian Cerrado.     

Microlicia crassa and M. maculata spp. nov. (Melastomataceae) from Minas Gerais,Brazil: morphology and leaf anatomy

Two new species of Microlicia from campos rupestres of Minas Gerais are described, illustrated and compared with their relatives. Microlicia crassa sp. nov. is similar to M. formosa, and M. maculata sp. nov. is similar to M. isophylla and M. tetrasticha. The trichomes covering both surfaces of the leaves of the two new species and their relative, M. isophylla may be characterized as sessile glands under a stereomicroscope, but anatomical studies revealed the presence of a short stalk. Microlicia crassa and M. maculata are assessed as “Endangered”, according to the IUCN categories and criteria.     

Seed germination requirements of Trembleya laniflora (Melastomataceae), an endemic species from neotropical montane rocky savannas

Trembleya laniflora is an endemic shrub from neotropical montane rocky savannas of southeastern Brazil. It has been indicated as a potential candidate for ecological restoration of abandoned iron‐ore mines due to heavy metal accumulation. Here, we evaluated the seed germination requirements of T. laniflora. Seeds collected in 2005 and 2008 were set to germinate under a broad range of temperature and light conditions. Seed viability was estimated by dissecting seeds under a dissecting microscope for embryo presence/absence. Seeds were photoblastic and optimum temperature range was 20–25°C, coinciding with the onset of the rainy season. Seeds were viable after 42 months of storage, which together with small seeds that easily get buried and light requirement for germination suggest formation of soil seed banks. Except the large fraction of embryoless seeds, almost all tested seeds germinated when incubated under light conditions; therefore, T. laniflora should be regarded to have nondormant seeds. Easiness of burial resulting from small seed size and positive photoblastism may both contribute to incorporation into soil seed banks. Our data suggest that the long‐term storage of T. laniflora seeds provides a useful strategy for plant reintroduction.     

Phylogeny and systematics of the tribe Sonerileae (Melastomataceae) in Africa: A revised taxonomic classification

The tribe Sonerileae in tropical Africa and Madagascar is a morphologically diverse lineage that consists of 239 species in 10 genera. In this study, we present the first in-depth phylogenetic analysis of African Sonerileae to test monophyly of the currently recognized genera. Phylogenetic analyses were performed using sequence data from two nuclear (nrITS and nrETS) and three plastid loci (accD-psaI, ndhF and psbK-psbL). Sampling consisted of 140 accessions including 64 African, 27 Malagasy, 46 Asian, and three neotropical Sonerileae together with a broad outgroup sampling (105 spp.). Phylogenetic relationships were inferred using maximum likelihood and Bayesian inference approaches, and a careful reassessment of morphological characters was carried out. Our results neither support the monophyly of the Old World nor African Sonerileae. The monospecific African genus Benna is partially supported as sister to Phainantha, one of the basal neotropical lineages, while African and Malagasy Medinilla are nested among the SE Asian genera. Gravesia (116 spp.), the most species-rich and morphologically diverse genus in Madagascar, is recovered as monophyletic. The African genera of Sonerileae Calvoa, Dicellandra, and Preussiella form well-supported clades. In contrast, Amphiblemma (including Amphiblemma molle) and Cincinnobotrys s.l. (including Cincinnobotrys felicis) are not monophyletic. To accommodate the caulescent C. felicis we propose reinstatement of the monospecific genus Bourdaria. For the distinctive A. molle a new genus Mendelia is described. Calvoa hirsuta is designated here as the type of genus Calvoa, lectotypes are designated for Medinilla engleri and Veprecella lutea, and a neotype is designated for Preussiella kamerunensis.     

Floral microcharacters in Lessingianthus (Vernonieae,Asteraceae) and their taxonomic implications

Micromorphological characters of 113 species of the South American genus Lessingianthus H.Rob. (Vernonieae, Asteraceae) were analyzed to evaluate their reliability as taxonomic markers. The corolla pubescence was studied in detail for the first time in the genus. Glandular and non-glandular trichomes were studied and described. The trichome types allow differentiation among related species, but do not reflect the relationships among species groups. On the other hand, the basal stylar node only occurs in a distinctive group of species within the genus. The apical appendage of the anthers is non-glandular in all species of the genus. Several character states analyzed in Lessingianthus are often widespread in other related genera of Vernonieae. Therefore, Lessingianthus can be circumscribed only by a combination of micro- and macromorphological features.     

Flavonoids of the primitive liverwort Takakia and their taxonomic and phylogenetic significance

The flavonoid chemistry of Takakia is described for the first time. T. lepidozioides, thought to be amongst the most primitive of extant liverworts, contains a high level and wide variety of flavone C- and O-glycosides, many of which are unique. New flavonoids include the 8-O-glucuronide and 8-O-xylosylglucoside of takakin (8-hydroxyacacetin), luteolin 6-C-arabinoside-8-C-pentoside, kaempferol 3-O-glucoside-7-O-xyloside and a number of tricetin C-glycosides. The only other known Takakia species, T. ceratophylla, contains the same 4 major constituents but significantly lacks flavonols. The often suggested relationship of Takakia with the order Calobryales is not supported by the available flavonoid data. Biochemical affinities of Takakia with all major liverwort orders are noted and the flavonoid data are interpreted as supporting the concept of Takakia as an isolated branch among the ancestors of modern bryophytes.     

A revision of Rhynchanthera (Melastomataceae)

The neotropical genus Rhynchanthera (Melastomataceae, Microlicieae) is revised, and 15 of the 84 proposed taxa are recognized; two species are excluded from the genus. The group consists of subshrubs and shrubs with usually purple flowers in thyrsoid inflorescences of uniparous or biparous cymes. It is characterized by androecia with five antepetalous staminodia in addition to the five fertile stamens, and - in most species - dimorphism of the stamens, with one strikingly longer than the other four. The plants always are covered by at least some simple glandular hairs. The majority of the species of Rhynchanthera occur in south-central Brazil, however, the range of the genus extends from southern Mexico to Bolivia and Paraguay. All species grow in wet places in open scrub or savanna vegetation. Micromorphological features of the seeds have been investigated and support the traditional placement of Rhynchanthera in the Microlicieae where it is closest to Microlicia, Lavoisiera , and Trembleya. Two taxa are illustrated with drawings, and the distribution of all is mapped.     

Taxonomic revision of Driessenia (Melastomataceae)

The genus Driessenia Korth. comprises fourteen species and two varieties. Eleven species are endemic to Borneo, the remaining three species occur on Sumatra, Java or Sulawesi. Five species ( D. sessiliflora, D. planopetiolata, D. attenuata, D. grandithyrsa and D. aequiappendiculata ), one variety ( D. microthrix Stapf var. pteroclada ) and one combination ( D. dispar (Cogn.)) are new. The genus Triuranthera Back. is made a synonym of Driessenia . The revision includes a key to the species, illustrations of various floral parts and maps of distribution.     

<Emphasis Type="Italic">Microlicia hirticalyx</Emphasis> (Melastomataceae): a new name for <Emphasis Type="Italic">Microlicia acuminata</Emphasis> Cogn.

The name Microlicia acuminata Cogn. is a later homonym of M. acuminata Naudin. Microlicia hirticalyx is proposed as a new name.     

The monotypic genus Cyphotheca (Melastomataceae)

Cyphotheca (Sonerileae s.l.), known only from China (Yunnan), is accepted as a monotypic genus most closely related to Phyllagalhis . The new name P. fengii C . Hansen is proposed for C. hispida , because the epithet hispida is not available in the genus Phyllagathis .