0000000000586217
AUTHOR
Regine Classen-bockhoff
Five new species of Marantaceae endemic to Gabon
ABSTRACT Five new species of African Marantaceae are described and illustrated from two locations in Gabon, Marantochloa alba A. C. Ley, sp. nov., M. grandiflora A. C. Ley, sp. nov., M. montsdecristalii A. C. Ley, sp. nov. and Thaumatococcus flavus A. C. Ley, sp. nov. from the mountainous area of Monts de Cristal, north east of the capital Libreville, as well as Hypselodelphys lopei A. C. Ley, sp. nov. from the central part of Gabon in secondary forest near La Lope and Mikongo. New keys to the genera Marantochloa Brongn. & Gris., Thaumatococcus Benth. and Hypselodelphys (K. Schum.) Milne.-Redh. are provided.
FLIES AS POLLINATORS OF MELITTOPHILOUS SALVIA SPECIES (LAMIACEAE)
UNLABELLED • PREMISE OF THE STUDY Floral adaptation to a functional pollinator group does not necessarily mean close specialization to a few pollinator species. For the more than 950 species of Salvia, only bee and bird pollinations are known. Restriction to these pollinators is mainly due to the specific flower construction (lever mechanism). Nevertheless, it has been repeatedly suggested that Salvia flowers might also be pollinated by flies. Are flies able to handle the lever mechanism? Are they functionally equivalent pollinators? In this study, we compared and quantified pollen transfer by bees and flies to test whether flies are true pollinators in Salvia.• METHODS We identified pollin…
Developmental analysis of merosity and sexual morphs in Rubiaceae: A case study in Rubia and Cruciata
The Rubiaceae is characterized by considerable diversity in floral features. To shed light on the variation of floral developmental patterns in Rubiaceae, a comparative study was carried out on pentamerous flowers of Rubia tinctorum L. and tetramerous flowers of Cruciata (Cruciata laevipes Opiz.; Cruciata glabra (L.) Ehrend.), two herbaceous genera of the tribe Rubieae. We aim to study the mechanism responsible for meristic variation and to discuss the expression of andromonoecy in C. laevipes. Developmental peculiarities include the time overlap in the initiation of petal and stamen whorls in Cruciata, the lack of calyx, and a very weak sympetaly in all species examined. Our results show t…
Towards a new classification of Salvia s.l.: (re)establishing the genus Pleudia Raf.
Salvia L. In its traditional circumscription is the largest genus within the mint family. To date, the magnitude of the task has rendered it difficult to provide a genus-wide revision based on morphological data. Current molecular investigations based on a dense taxon sampling representing the whole phenotypic diversity and distribution range of Salvia confirmed that the genus is polyphyletic. Salvia species fall in 4 distinct clades, although all of them, except Clade IV, also include non-Salvia genera. A taxonomic revision is thus urgently needed with two different approaches that have to be considered: (1) to include the 5 morphologically distinct non-Salvia genera in Salvia or (2) to sp…
Flower ontogeny inCapparis spinosa(Capparaceae) with special emphasis on symmetry expression
The flower ontogeny of Capparis spinosa L. was studied using scanning electron microscopy (SEM) in order to shed light on the early expression of symmetry in a representative member of Capparaceae. Sepals start decussately with the abaxial and adaxial sepals, followed by the lateral ones. Petal appearance proceeds uni-directionally from the abaxial to the adaxial side. Stamens develop centrifugally on an androecial ring. Five to seven carpel lobes arise on a gynoecial ring. Monosymmetry is established in early development by the uni-directional petal appearance and is further enhanced by the acquisition of an abaxial nectary appendage and differential development of perianth organs at anthe…
Modeling dense inflorescences
Showy inflorescences - clusters of flowers - are a common feature of many plants, greatly contributing to their beauty. The large numbers of individual flowers (florets), arranged in space in a systematic manner, make inflorescences a natural target for procedural modeling. We present a suite of biologically motivated algorithms for modeling and animating the development of inflorescences with closely packed florets. These inflorescences share the following characteristics: (i) in their ensemble, the florets form a relatively smooth, often approximately planar surface; (ii) there are numerous collisions between petals of the same or adjacent florets; and (iii) the developmental stage and ty…
Functional implications of the staminal lever mechanism in Salvia cyclostegia (Lamiaceae)
Flower morphology and inflorescence architecture affect pollinator foraging behaviour and thereby influence the process of pollination and the reproductive success of plants. This study explored possible ecological functions of the lever-like stamens and the floral design in Salvia cyclostegia.Flower construction was experimentally manipulated by removing either the lower lever arms or the upper fertile thecae of the two stamens from a flower. The two types of manipulated individuals were intermixed with the control ones and randomly distributed in the population.Removing the sterile lower lever arms significantly reduced handling time per flower of the main pollinator, Bombus personatus. I…