E. Nic Lughadha

Measuring the fate of plant diversity: towards a foundation for future monitoring and opportunities for urgent action

Vascular plants are often considered to be among the better known large groups of organisms, but gaps in the available baseline data are extensive, and recent estimates of total known (described) seed plant species range from 200 000 to 422 000. Of these, global assessments of conservation status using International Union for the Conservation of Nature (IUCN) categories and criteria are available for only approximately 10 000 species. In response to recommendations from the Conference of the Parties to the Convention on Biological Diversity to develop biodiversity indicators based on changes in the status of threatened species, and trends in the abundance and distribution of selected species, we examine how existing data, in combination with limited new data collection, can be used to maximum effect. We argue that future work should produce Red List Indices based on a representative subset of plant species so that the limited resources currently available are directed towards redressing taxonomic and geographical biases apparent in existing datasets. Sampling the data held in the worlds major herbaria, in combination with Geographical Information Systems techniques, can produce preliminary conservation assessments and help to direct selective survey work using existing field networks to verify distributions and gather population data. Such data can also be used to backcast threats and potential distributions through time. We outline an approach that could result in: (i) preliminary assessments of the conservation status of tens of thousands of species not previously assessed, (ii) significant enhancements in the coverage and representation of plant species on the IUCN Red List, and (iii) repeat and/or retrospective assessments for a significant proportion of these. This would result in more robust Sampled Red List Indices that can be defended as more representative of plant diversity as a whole; and eventually, comprehensive assessments at species level for one or more major families of angiosperms. The combined results would allow scientifically defensible generalizations about the current status of plant diversity by 2010 as well as tentative comments on trends. Together with other efforts already underway, this approach would establish a firmer basis for ongoing monitoring of the status of plant diversity beyond 2010 and a basis for comparison with the trend data available for vertebrates.

Phylogenetic patterns in the fleshy-fruited Myrtaceae – preliminary molecular evidence

Abstract.A phylogenetic study of selected fleshy-fruited genera of the Myrtaceae was conducted using sequences from the ITS region of nuclear DNA and the psbA-trnH region of plastid DNA. Studies to date have suggested that the fleshy-fruited state has arisen on several occasions in the Myrtaceae. The previously accepted and predominantly Neotropical tribe Myrteae has traditionally been divided into three groups, the subtribes Myrtinae, Eugeniinae and Myrciinae. This subtribal arrangement is analysed in detail here for the first time. The monophyly of the tribe and subtribes are tested and relationships of the genera within them, in particular those of the Myrciinae and anomalous genera sometimes associated with it, are discussed. Combined analyses of these two DNA regions revealed 40 shortest trees, all of which resolve Myrteae (excluding the Acmena group) as monophyletic. Myrciinae appears to be monophyletic whereas Myrtinae and Eugeniinae appear polyphyletic. The phylogenetic positions and relationships of the anomalous genera Myrceugenia,Luma and Blepharocalyx are unclear, but Myrceugenia is never included within the Myrciinae s.str. A Myrciinae s.str. clade emerges within which Myrcia,Calyptranthes and Marlierea appear polyphyletic. Clades emerge, however, that may reflect some natural groupings within the subtribe.

Polysporangiate Anthers: Described for the First Time in Melastomataceae

In taxonomic studies of the Melastomataceae anther morphology has been used along with fruit and seed characters to distinguish taxa mainly at a supraspecific level (among others De Candolle 1828a, b; Don 1832; Spach 1835; Grisebach 1864; Hooker 1867; Cogniaux 1883, 1891; Krasser 1893; Pereira 1961; Barroso et al. 1984). Characters used include the number and length of the stamens or anthers, position and form of the anther connective and the presence and type of indumentum on the stamens as well as the incidence of stamen dimorphism. Recent taxonomic revisions of genera of Melastomataceae and treatments of species of this family for local floras have shown that details of stamen morphology are important in the distinction of species or species groups, as may be observed in publications by Souza (1988), Baumgratz (1990), Renner (1989a, 1990, 1994), Martins (1989), Chiea (1990), Romero (1993), Wurdack et al. (1993), Baumgratz & Souza (1995) and Woodgyer & Nic Lughadha (1995). The anthers of the Melastomataceae are generally described as tetrasporangiate, dithecal, and bilocular at maturity. The single exception is Rhexia which although tetrasporangiate, is unithecal and becomes unilocular at anthesis through a breakdown of the septa. (Kral & Bostick 1969, Cronquist 1981, Renner 1993). During the preparation of the Melastomataceae account for the Flora of the Pico das Almas, in the state of Bahia, Brazil, (Baumgratz & Souza 1995) anthers of an apparently polysporangiate nature were encountered in two species of Chaetostoma , a phenomenon hitherto unknown in the Melastomataceae. The discovery gave rise to questions as to the importance of this character not only in the taxonomy of the tribe Microlicieae but also in the family as a whole. The taxonomy of the Microlicieae has long been recognised as problematic (Baillon 1880), and several of the genera within it are sorely in need of revision.

Three new species of Myrcia section Gomidesia (Myrtaceae) — from Espírito Santo, Brazil

SummaryThree new species of Myrcia sect. Gomidesia: M. curtipendula Nic Lughadha, M. aurea Nic Lughadha and M. teresensis Nic Lughadha, from Espírito Santo are described. Their diagnostic characters and habitat are discussed; IUCN categories of threat are assigned.

Additions to Myrcia s.l. from Eastern Brazil — taxonomic and nomenclatural novelties in Myrcia s.l. (Myrtaceae)

SummaryTwo new species of Myrcia from Bahia are described and a new combination and status of Myrcia from southern Brazil is proposed. Their diagnostic characters and habitat are discussed and IUCN categories of threat are assigned.

Notes on Thai Myrtaceae

During the preparation of an account of the Myrtaceae (other than Eugenia s.l.) for the Flora of Thailand several points of interest arose which can more appropriately be discussed here than in the Flora itself. A new subspecies of the variable Decaspermum parviflorum is described and the specific description is amplified, new combinations are made in Rhodamnia and Tristaniopsis and the nomenclature of the widespread Rhodamnia dumetorum is clarified.

A new infra-generic classification of the species-rich Neotropical genus Myrcia s.l.

SummaryA new classification of the large Neotropical genus Myrcia s.l. is proposed. Nine sections are presented that correspond to recently published clades. Of these nine sections, sects. Myrcia, Aulomyrcia and Sympodiomyrcia are already published, sects. Reticulosae and Tomentosae are new sections, sect. Eugeniopsis is a new combination whilst sects. Aguava, Calyptranthes and Gomidesia are new combinations at a new rank (comb. & stat. nov.). Six lectotypifications are made for sections or genera. Estimates of species per section are listed.

A new species and a replacement name in Myrcia ( Gomidesia ; Myrtaceae) from north-eastern Brazil

SummaryA new species of Myrcia, M. rosangelae NicLugh., from north-eastern Brazil is described and illustrated, and a conservation assessment based on IUCN criteria is given. A replacement name is also published, M. neoblanchetiana Sobral & E. Lucas.

Gomidesia cordiifolia (Myrtaceae): a new combination for a little known species from southeastern Brazil.

Summary. The new combination Gomidesia cordiifolia (DC.) Nic Lughadha is made to replace the superfluous name G. linkiana 0. Berg. The name Myrcia cordiifolia DC. is lectotypified and discussed in relation to Myrcia cordifolia 0. Berg.