Claudia Petean Bove

Phylogeny of the clusioid clade (Malpighiales): Evidence from the plastid and mitochondrial genomes

PREMISE OF THE STUDY The clusioid clade includes five families (i.e., Bonnetiaceae, Calophyllaceae, Clusiaceae s.s., Hypericaceae, and Podostemaceae) represented by 94 genera and ≈1900 species. Species in this clade form a conspicuous element of tropical forests worldwide and are important in horticulture, timber production, and pharmacology. We conducted a taxon-rich multigene phylogenetic analysis of the clusioids to clarify phylogenetic relationships in this clade. METHODS We analyzed plastid (matK, ndhF, and rbcL) and mitochondrial (matR) nucleotide sequence data using parsimony, maximum likelihood, and Bayesian inference. Our combined data set included 194 species representing all major clusioid subclades, plus numerous species spanning the taxonomic, morphological, and biogeographic breadth of the clusioid clade. KEY RESULTS Our results indicate that Tovomita (Clusiaceae s.s.), Harungana and Hypericum (Hypericaceae), and Ledermanniella s.s. and Zeylanidium (Podostemaceae) are not monophyletic. In addition, we place four genera that have not been included in any previous molecular study: Ceratolacis, Diamantina, and Griffithella (Podostemaceae), and Santomasia (Hypericaceae). Finally, our results indicate that Lianthus, Santomasia, Thornea, and Triadenum can be safely merged into Hypericum (Hypericaceae). CONCLUSIONS We present the first well-resolved, taxon-rich phylogeny of the clusioid clade. Taxon sampling and resolution within the clade are greatly improved compared to previous studies and provide a strong basis for improving the classification of the group. In addition, our phylogeny will form the foundation for our future work investigating the biogeography of tropical angiosperms that exhibit Gondwanan distributions.

Hidrófitas fanerogâmicas de ecossistemas aquáticos temporários da planície costeira do Estado do Rio de Janeiro, Brasil

ABSTRACT – (Phanerogamic hydrophytes from the temporary swampy environments of coastal plains ofnorthern Rio de Janeiro State, Brazil). A floristic inventory of phanerogamic hydrophytes from the temporaryswampy environments of coastal plains of northern of Rio de Janeiro State was made. The botanical voucherswere collected in 27 expeditions between September/1998 and July/2001. They were herborized and identified bythe traditional methodology. The exsicatae were deposited in the UNIRIO herbarium (HUNI). One hundred andthirteen taxa, distributed among 40 families were found. The environment analyzed could be floristically characterizedby the Cyperaceae, represented by 23 taxa (ca. 20%), followed by Fabaceae and Onagraceae (seven taxa), Poaceae(six taxa), Asteraceae and Scrophulariaceae (five taxa) and Apiaceae, Lentibulariaceae and Polygonaceae (four 1 Laboratorio Integrado de Sistematica e Palinologia de Hidrofitas Vasculares, Departamento de Ciencias Naturais, Universidadedo Rio de Janeiro (UNIRIO), Rua Frei Caneca, 94, CEP 20211-040 Rio de Janeiro, RJ, Brasil (cpbove@ibpinet.com.br)

ENDEMISM IN NEOTROPICAL PODOSTEMACEAE

Abstract Podostemaceae, a family of plants restricted to river rapids and waterfalls, are widely reported to have a high degree of local species endemism. We tested this idea for Neotropical members of the family using historical records, herbarium holdings, personal field collections, and geographic information systems analyses. In contrast to estimates of endemism based on the landmark studies of P. van Royen (66%), we report 15%–37% based on current taxonomy. Examples of regional endemism, based on extent of occurence and longest geographic axis measures, are discussed for a subset of species. Major hydrographic regions (Amazon River System, Paraná River System) and major areas (eastern Brazil) are shown to possess largely unique podostemad floras. We propose rivers and river systems as the most appropriate units to assess endemism for Podostemaceae, and consider one-river and two-river endemics as narrowly distributed. Limitations in the current taxonomy are discussed relative to establishment of meaningful estimates of local species endemism. We provisionally apply IUCN assessment categories to Neotropical Podostemaceae and report that approximately one third of the species fall into one of three categories: Data Deficient (DD), Least Concern (LC), and Vulnerable (VU). Ten species are Critically Endangered (CR). Species of Podostemaceae are restricted to an environment that has experienced major human impacts—tropical rivers. Large dams make long reaches of rivers inhospitable. Expanded use of hydropower in Latin America will exacerbate the problem.

Systematics and Phylogeny of Neotropical Riverweeds (Podostemaceae: Podostemoideae)

Abstract New World Podostemaceae (riverweeds) comprise approximately 135 species in 21 genera, most of which are of tropical distribution, shed pollen in monads, and belong to subfamily Podostemoideae. We undertook a phylogenetic study of Neotropical Podostemoideae using molecular (ITS, rbcL, trnL) and morphological data, to assess the monophyly of genera and their interrelationships. Extensive taxon sampling (38 taxa in 15 genera) revealed that the large genera Apinagia and Marathrum are not monophyletic as currently circumscribed, although several species of the former comprised a clade that could be delimited morphologically by the shared character of upright stems (i.e. anchored to the substrate only basally). Marathrum species were split geographically, with Central and South American taxa resolving in different clades. Oserya also comprised two geographically disparate clades, with the type species belonging to the South American clade. To establish the monophyly of Oserya, we erected a new genus Noveloa to accommodate the Central American species N. coulteriana and N. longifolia. The Central American Marathrum clade included the monotypic Vanroyenella, which we transferred to that genus as Marathrum plumosum. The genera Castelnavia and Rhyncholacis were monophyletic in our analyses; C. multipartita f. pendulosa was elevated to species rank as Castelnavia pendulosa. The monotypic Lonchostephus resolved within Mourera, with which it shares a number of morphological features that are found also in Tulasneantha (also monotypic), but which otherwise are unique in Podostemaceae. We recommend that Lonchostephus and Tulasneantha be merged with Mourera and provide the new combination Mourera monadelpha for the latter. Finally, an unexpected clade of morphologically diverse genera, including members of Apinagia, Jenmaniella, Lophogyne, Marathrum, and Monostylis, resolved with strong support but uncertain morphological integrity, as sister to all ingroup taxa except Mourera. However, nomenclatural changes in this group have not been made, pending additional taxon sampling and procurement of further molecular and morphological evidence.

Bimodality in stable isotope composition facilitates the tracing of carbon transfer from macrophytes to higher trophic levels

Even though the suitability of macrophytes to act as a carbon source to food webs has been questioned by some studies, some others indicate that macrophyte-derived carbon may play an important role in the trophic transfer of organic matter in the food web of shallow lakes. To evaluate the importance of macrophytes to food webs, we collected primary producers—macrophytes and periphyton—and consumers from 19 South American shallow lakes and analyzed their carbon stable isotopes composition (δ13C). Despite the diversity of inorganic carbon sources available in our study lakes, the macrophytes’ δ13C signatures showed a clear bimodal distribution: 13C-depleted and 13C-enriched, averaging at −27.2 and −13.5‰, respectively. We argue that the use of either CO2 or HCO3− by the macrophytes largely caused the bimodal pattern in δ13C signals. The contribution of carbon from macrophytes to the lake’s food webs was not straightforward in most of the lakes because the macrophytes’ isotopic composition was quite similar to the isotopic composition of periphyton, phytoplankton, and terrestrial carbon. However, in some lakes where the macrophytes had a distinct isotopic signature, our data suggest that macrophytes can represent an important carbon source to shallow lake food webs.

Monograph of Castelnavia (Podostemaceae)

Abstract A monograph of Castelnavia is presented. Phylogenetic analyses of morphological characters reveal eight nonhomoplasious synapomorphies supporting the monophyly of the genus: 1) absence of roots, a 2) unilocular mature, 3) anisolobous ovary that is 4) surrounded by stem tissue during and after anthesis, 5) horizontal at anthesis, with an 6) asymmetrically inflated pedicel apex and 7) longitudinal axis at 45–90° angle relative to pedicel axis, and 8) one deciduous capsule valve. Five species and two forms are recognized: Castelnavia fluitans, C. monandra, C. multipartita (C. m. forma multipartita, C. m. forma pendulosa C. T. Philbrick & C. P. Bove), C. noveloi, and C. princeps. Four species accepted by earlier authors are placed in synonymy. The morphology and ecology of the genus is discussed, and species descriptions, illustrations, a distribution map, lists of specimens examined, and a key to species are presented. Castelnavia occurs primarily in Brazil with one species in Bolivia. The greatest species diversity is in the Brazilian states of Mato Grosso, Pará, and Tocantins.

Eleocharis R.Br. (Cyperaceae) no Estado do Rio de Janeiro, Brasil

A floristic inventory of the species of Eleocharis (Cyperaceae) from Rio de Janeiro State - Brazil was made. This research included material from most important Herbaria of Rio de Janeiro (FCAB, GUA, HB, HUNI, R, RB, RBR, RFA, RUSU) as well as plants collected during expeditions to aquatic ecosystems of Rio de Janeiro, between November 1998 and September 2003. The genus Eleocharis is represented in the area by 19 species: Eleocharis acutangula (Roxb.) Schult., E. debilis Kunth, E. elongata Chapm., E. equisetoides (Elliott) Torr., E. filiculmis Kunth, E. flavescens (Poir.) Urb., E. geniculata (L.) Roem. & Schult., E. interstincta (Vahl) Roem. & Schult., E. maculosa (Vahl) Roem. & Schult., E. minarum Boeck.*, E. minima Kunth, E. montana (Kunth) Roem. & Schult., E. mutata (L.) Roem. & Schult., E. nana Kunth, E. pachystyla (C. Wright) C. B. Clarke*, E. radicans (Poir.) Kunth*, E. sellowiana Kunth, E. squamigera Svenson, and E. subarticulata (Nees) Boeck. (*species rare in Rio de Janeiro state). A key of identification, descriptions of species, illustrations, and notes on ecological features and geographical distribution are presented.

Dispersal largely explains the Gondwanan distribution of the ancient tropical clusioid plant clade

PREMISE OF THE STUDY The clusioid clade (Malpighiales) has an ancient fossil record (∼90 Ma) and extant representatives exhibit a pantropical distribution represented on all former Gondwanan landmasses (Africa, Australia, India, Madagascar, and South America) except Antarctica. Several biogeographers have hypothesized that the clusioid distribution is an example of Gondwanan vicariance. Our aim is to test the hypothesis that the modern distribution of the clusioid clade is largely explained by Gondwanan fragmentation. METHODS Using a four gene, 207-taxon data set we simultaneously estimated the phylogeny and divergence times of the clusioid clade using a Bayesian Markov chain Monte Carlo approach. Ancestral Area Reconstructions (AARs) were then conducted on a distribution of 1000 trees and summarized on a reduced phylogeny. KEY RESULTS Divergence time estimates and AARs revealed only two or four cladogenic events that are potentially consistent with Gondwanan vicariance, depending on the placement of the ancient fossil Paleoclusia. In contrast, dispersal occurred on > 25% of the branches, indicating the current distribution of the clade likely reflects extensive recent dispersal during the Cenozoic (< 65 Ma), most of which occurred after the beginning of the Eocene (∼56 Ma). CONCLUSIONS These results support growing evidence that suggests many traditionally recognized angiosperm clades (families and genera) are too young for their distributions to have been influenced strictly by Gondwanan fragmentation. Instead, it appears that corridors of dispersal may be the best explanation for numerous angiosperm clades with Gondwanan distributions.

Floral structure and palynology of Podostemum weddellianum (Podostemaceae: Malpighiales)

The family Podostemaceae is exceptional among angiosperms because of its uncommon biology and morphology, the absence of double fertilisation and endosperm, and the obscure distinction between root, stem, and leaf. The highly modified morphology produced by reductions and specialisations is reflected in the multiple positions that the Podostemaceae has occupied in different classification systems. In the family, structural studies are mainly related to the vegetative body. In the genus Podostemum, structural data are related to the development and embryology of Podostemumceratophyllum Michx., which, with P. weddellianum, has pre-anthesis cleistogamy. P. weddellianum is analysed for the first time with regard to floral structure and palynology. The presence of silica in the spathella, the apical septum in the ovary, dyads and pseudomonads, unimodal embryo sac and chasmogamous flowers with the possibility of self-pollination contribute to the characterisation of the Podostemoideae and the search for relationships among Podostemaceae and the clusioids.

A New Species of Cipoia (Podostemaceae) from Minas Gerais, Brazil

Abstract A new species of Cipoia (Podostemaceae) from the state of Minas Gerais (Brazil) is described and illustrated: Cipoia ramosa. It is distinguished from the only other species in the genus, C. inserta, by its branched stems, stipules composed of two tooth-shaped appendages adjacent to the leaf base, anther thecae that remain at a prominent angle during and after anthesis, and an ovary that is longer than the stigmas at anthesis.