Calystegines in wild and cultivated Erythroxylum species

Calystegines were identified in the genus Erythroxylum for the first time. Erythroxylum novogranatense var. novogranatense, a species cultivated for cocaine production, contained 0.2% total calystegines in dry leaves. Forty six Erythroxylum herbarium species consisting mostly of leaf tissue were analysed for calystegines, and 38 were found positive. Calystegines were compared qualitatively and quantitatively between individual Erythroxylum species. Calystegines A(3) and B(2) were the major calystegines in most species. Total calystegine content reached up to 0.32% dry mass. The simultaneous occurrence of calystegines, cocaine, other alkaloids of a 3alpha-hydroxy- or 3beta-hydroxytropane structure together with nicotine supports the concept of common biosynthetic steps of these alkaloids in Erythroxylum. The present results are the basis for further investigations of the phylogenetic origin of tropane alkaloid biosynthesis in the taxonomically remote families Solanaceae and Erythroxylaceae.     

Distyly and heteromorphic incompatibility in oceanic island species ofErythroxylum (Erythroxylaceae)

Surveys of oceanic island floras have shown that heterostyly is usually absent in such regions, probably because this floral polymorphism is often associated with a self-incompatibility system. In this context we describe the floral biology of three species ofErythroxylum on La Réunion island and examine the compatibility relationships of one of these species,E. laurifolium. All three species are distylous but differ in relative stigma-anther separation in the different morphs. In general, short-styled flowers have greater stigma-anther separation than long-styled flowers, which are often homostylous in appearance. This lack of stigma-anther separation in long-styled flowers is due to style twisting which improves reciprocity at the high organ level. The reduced stigma-anther separation does not appear to be associated with the evolution of selfing asErythroxylum laurifolium shows heteromorphic self-incompatibility. The presence of heteromorphic incompatibility in a group of species that have colonized an oceanic island is discussed.     

Morph-biased male sterility in the tropical distylous shrub Erythroxylum havanense (Erythroxylaceae)

This study explores whether ecological factors, such as pollinators and pollen flow, or variation in pollen and ovule development account for the observed differences (approximately twofold) in the reproductive output of pin and thrum individuals of Erythroxylum havanense. The importance of ecological factors was assessed by means of comparison of the identity of pollinators and the rates of flower visitation, and by performing controlled hand pollinations and measurements of fruit set. In addition, we described the pollen and ovule development of thrum and pin individuals. Our results indicate that pollinators of E. havanense do not distinguish between floral morphs. The differences in fruit set between pin and thrum plants held even after hand pollination and, therefore, the observed differences in reproductive output between floral morphs of E. havanense cannot be explained in terms of asymmetrical pollen flow. There were no differences in the pattern of gynoecium development between the pin and thrum morphs, however androecium development showed marked differences between the morphs, and there was a resemblance between the developmental pathways leading to male sterility of the thrum morph of E. havanense with that of species with cytoplasmic male sterility (CMS).     

Agouticarpa, a new neotropical genus of Tribe Gardenieae (Rubiaceae)

Agouticarpa, a new genus of the informalAlibertia group (Rubiaceae), is described and illustrated. It comprises six species, and occurs from Costa Rica to Bolivia. Three species are here described as new:Agouticarpa grandistipula, A. hirsuta, andA. velutina. Additionally, three new combinations are made:A. curvifolia andA. williamsii (previously inGenipa) andA. isernii (previously inAlibertia). Agouticarpa is characterized by being dioecious, having elliptic to abovate, membranaceous stipules, male flowers in a branched dichasial or thyrse-like inflorescence, a poorly developed cup-shaped calyx, pollen grains with 3–7 apertures, and large globose fruits.     

Redefinition of the neotropical genus Anthopterus (Ericaceae: Vaccinieae), including one new species

The taxonomic history of Anthopterus as it relates to Themistoclesia is briefly reviewed. Anthopterus is redefined to include several species formerly placed in Themistoclesia. Two subgenera are established within Anthopterus. Anthopterus costaricensis Luteyn is described as new, and the new combination Anthopterus pterotus (A. C. Sm.) Luteyn is made. A key to the genus, a list of the species currently accepted, and brief notes on distribution and frequency are provided. Most species of Anthopterus are rare and their habitats are endangered.     

Heterostyly in Erythroxylum coca (Erythroxylaceae)

Erythroxylum coca is a distylous species with a strong self-incompatibility system linked with the floral dimorphism. The two sets of stamens in the flowers are usually unequal in length, but between individuals of both morphs there is considerable variation in the relative qengths of the two sets of stamens, which is unrelated to the incompatibility system. Pin flowers produce more pollen grains than thrum flowers, but thrum pollen is larger than pin pollen. Within each morph the two sets of stamens produce pollen grains of slightly different diameter. Erythroxylum novogranatewe is also distylous. Pin flowers of E. novogranatense var. novogranatense are partially self-compatible, while thrum flowers of E. novogranatense var. truxillense are self-incompatible. Reports of tristyly and of four different morphs in species of Erythroxylum are probably misinterpretations, resulting from limited sampling, of the continuous variation in the relative lengths of the two sets of stamens.     

Pre-dispersal seed predation reduces the reproductive compensatory advantage of thrum individuals in Erythroxylum havanense (Erythroxylaceae)

Male-sterility mutations in hermaphroditic species represent the first step in the evolution of gender specialization. Male-sterile individuals commonly compensate the loss of the male function by increasing the number or quality of seeds. Because the magnitude of compensation determines the maintenance of females within populations and the evolution of sexual specialization, plant-animal interactions may affect these evolutionary processes if animals are sensitive to such reproductive asymmetries. Here we explore the effect of seed predation on the reproductive compensation of Erythroxylum havanense, a distylous shrub with morph-biased partial male sterility, during two consecutive years. Seed predation reduced the compensatory advantage of thrums in 1987, but not in 1988. Annual differences in the intensity of seed predation seem to be accounted for differences in the onset and synchrony of flowering. Thus, although seed predators may reduce the compensatory advantage of thrums, their impact is modulated by the environmental cues triggering flowering and insect emergence.     

Review of the neotropical endemics Burmeistera, Centropogon, and Siphocampylus (Campanulaceae: Lobelioideae), with description of 18 new species and a new section

Burmeistera, Centropogon, and Siphocampylus together comprise more than 500 species endemic to the Neotropics, Current knowledge of these genera is unsatisfactory, with much diversity yet to be described. Over the past seven years, one out of every 28 specimens received for identification has represented a new species, many characterized by unique or unusual character states. Siphocampylus smilax (Bolivia) is unique in the genus in its parallelodromous leaf venation and extra-floral nectaries. Centropogon dianae (Peru) cannot be accommodated in any recognized infrageneric taxon, and a new section, Centropogon sect. Niveopsis, is proposed for it. The flowers of C. steinii (Ecuador) are the smallest known in the genus, while C. connatilobatus (Venezuela) is the first species to combine arbusculiform pubescence and connate calyx lobes. Burmeistera venezuelensis is only the second species of the genus known to occur in Venezuela and the first to be endemic; similarly, Centropogon wilburii is only the third species of Centropogon known from Mexico and the first to be endemic to that country. Additional novelties are also described.     

Local genetic differentiation among populations of the mass-flowering tropical shrub Erythroxylum havanense (Erythroxylaceae)

This study is aimed to understand the role of life-history traits in determining the genetic structure of populations. We used Erythroxylum havanense, a distylous shrub with synchronous and massive patterns of flowering and fruiting. We suggest that the high concentration of ephemeral resources produced by mass flowering satiates both pollinators and frugivores, restricting gene flow and leading to genetic differentiation among populations. Using random amplified polymorphic DNAs as genetic markers, we estimated genetic diversity and structure statistics to quantify the amount and distribution of genetic variation within and among five populations from the Pacific coast of Mexico. High levels of genetic variation within populations and significant differentiation among populations located very near to each other were found. Furthermore, spatial autocorrelation analysis indicated the presence of significant genetic structure at short spatial distances. We suggest that by influencing the foraging behavior of pollinators and frugivores, mass flowering may produce the observed patterns of genetic structure, while small differences in flowering or fruiting phenology could further reinforce the isolation of nearby populations.     

Dacryodes edilsonii, a new species from southwestern Amazonia. Studies in neotropical Burseraceae XII

Dacryodes edilsonii Daly (Burseraceae) is one of at least 14 still undescribed neotropical species in the genus; it is also one of a large number of new species emerging from intensified botanical exploration of the Brazilian state of Acre in southwestern Amazonia. The new species is easily distinguished from most other Neotropical species of the genus by its usually densely long-pubescent petiole, rachis, petiolules, and abaxial midvein.     

Monograph of the neotropical species of Callipteris with anastomosing veins (Woodsiaceae)

Callipteris is a pantropical fern genus defined by two synapomorphies of its rhizome scales: 1) dark-castaneous to black borders, and 2) bifid marginal teeth. This monograph treats 15 neotropical species ofCallipteris that are further defined by the synapomorphy of anastomosing veins (free-veined species of the genus occur in the Neotropics and elsewhere). Three species are newly described here; the remaining 12 were previously classified inDiplazium. All the species ofCallipteris grow on wet forest floors at 100–2300 m. In the Neotropics the genus occurs from Guatemala to Bolivia, northern Brazil, and the Lesser Antilles. It has two centers of species richness. The first is the Chocó region on the western side of the Andes in Colombia and northwestern Ecuador. This region contains eight species, five of which are endemic. The second center is the mountains of Costa Rica and Panama, where six species occur, three of which are endemic. Only one species, an endemic, occurs in the Lesser Antilles in Martinique, St. Vincent, and Grenada. Four species occur only on the eastern side of the Andes, and these apparently represent at least two separate dispersal events from the western side of the Andes.     

Two new species of Protium from French Guiana. Studies in neotropical Burseraceae VIII

Revision of Protium in French Guiana has revealed two new species. Protium gallicum is related to P. aracouchini (Aubl.) Marchand and P. elegans Engl., although its fruits resemble those of P. plagiocarpium Bénoist. Protium inodorum, which also occurs in northern Pará, Brazil, is related to P. pallidum Cuatrec. and P. cuneatum Swart; it is known only from flowers and very young fruits. Even in relatively well-known regions of tropical forest, botanical exploration continues to yield new taxa.     

Asplenium (sect. Hymenasplenium) basiscopicum, a new species from Bolivia

Asplenium basiscopicum is described, illustrated, and compared to the most similar species,A. purpurascens.     

New species, nomenclatural changes and lectotypifications in Neotropical Lepidagathis Willd. (Acanthaceae)

Summary  Taxonomic and phylogenetic studies of the Neotropical genus Lophostachys showed that it is congeneric with Lepidagathis. The following new combinations of species previously described under Lophostachys are proposed: Lepidagathis chiapensis (Acosta) Kameyama, L. cyanea (Leonard) Kameyama, L. guatemalensis (Donn. Sm.) Kameyama, L. laxifolia (Nees) Kameyama, L. montana (Nees) Kameyama, L. nemoralis (Mart. ex Nees) Kameyama, L. soconuscana (T. F. Daniel) Kameyama, and L. uxpanapensis (Acosta) Kameyama. Five new species are described: Lepidagathis callistachys, L. cuneiformis, L. meridionalis, L. paraensis and L. wasshausenii. Three lectotypes are also designated. A key to the Neotropical secundiflorous species is provided.