Botanical Journal of the Linnean Society

VARASSIN, ISABELA GALARDA; TRIGO, JOSÉ ROBERTO; SAZIMA, MARLIES

doi: 10.1111/j.1095-8339.2001.tb00563.xpmid: N/A

AbstractThe pollination biology of four species of passionflower was studied in south-eastern Brazil, specifically the importance of chemical features of floral nectar, pigments and odours. All species required pollinators to produce fruits: P. alata was pollinated by bees, P. speciosa by hummingbirds, and P. galbana and P. mucronata by bats. Pollinators consumed nectar as a food source. The activity of vertebrate pollinators reflected resource availability: they foraged when large amounts of nectar were available and when quantitative resource predictability was greater. The nectar of the vertebrate-pollinated species was richer in cholesterol and phospholipids, and had a potassium-sodium ratio higher than 1.0. For all species, the light absorption of flowers was paralleled by the pollinators' visual spectral sensitivity. This first report on Passiflora floral volatile compounds showed that there was a greater chemical class diversity among the species pollinated by animals with an acute olfactory sense, such as bees and bats. Benzenoid alcohols were the most represented compounds. The fragrances contained compounds that occur in other plant species and in the exocrine secretions of bees. This study shows a strong association between pollinators and the attracting and rewarding features of flowers.

STERN, WILLIAM LOUIS; JUDD, WALTER S.

doi: 10.1111/j.1095-8339.2001.tb00564.xpmid: N/A

AbstractCatasetinae consist of five genera of pseudobulbous Orchidaceae of the Neotropics. Anatomy is characterized by sunken, three-celled foliar hairs, mostly tetracytic stomatal apparatuses, superficial stomata, homogeneous mesophyll, foliar fibre bundles, collateral vascular bundles in a single row, xylem and phloem sclerenchyma associated with vascular bundles in leaves, conical, and rough-surfaced silica bodies adjacent to vascular bundle sclerenchyma; epidermal cells of pseudobulbs with heavily thickened outer walls, pseudobulb ground tissue of assimilatory and water-storage cells, scattered vascular bundles in pseudobulbs, and sclerenchyma and stegmata associated only with phloem of pseudobulbs; roots with thin-walled velamen cells and tenuous spirals of cell wall material, distinctive epivelamen cells, thin-walled exodermal cells and vascular tissue embedded in parenchyma. Except for mucilaginous idioblasts that occur in Mormodes and Cycnoches, there are few outstanding anatomical differences among the five genera. Thus, there are few anatomical characteristics of phylogenetic value. The monophyly of Catasetinae is supported by the presence of sunken foliar hairs. Our results support a close relationship between Clowesia and Catasetum, and between Mormodes and Cycnoches. Among the outgroups Pteroglossaspis is especially distinctive.

FIGUEIREDO, ESTRELA

doi: 10.1111/j.1095-8339.2001.tb00565.xpmid: N/A

AbstractA revision of the genus Calvoa Hook. f. (Melastomataceae) is presented. Principal Component Analyses (PCA) and Cluster Analyses (UPGMA) were performed to elucidate three cases of difficult species delimitation and infraspecific variation, with the following results. (1) The separation between C. crassinoda Hook. f. and C. grandifolia Cogn. was clear in the results obtained with both methods. (2) The group of the West-Central African species Calvoa angolensis A. Fern. & R. Fern., C. calliantha Jacq.-Fél., C. monticola A. Chev., C. pulcherrima Gilg ex Engl., C. sapinii De Wild., C. seretii De Wild., C. sinuata Hook. f. and C. subquinquenervia De Wild, proved difficult to resolve with either analysis, but the Cluster Analysis produced results which are more consistent with the identification of the specimens. (3) Neither of the two analyses supported the recognition of infraspecific categories in Calvoa orientalis Taub. Eighteen species are recognized in the genus. The new species Calvoa Jacques-felixii E. Figueiredo is described and the new combination Calvoa seretii subsp. wildemaniana (Exell) E. Figueiredo is made. Four lectotypes are designated. The conservation status of some taxa is discussed. Six species are considered rare and possibly under threat.

LENG, QIN; YANG, HONG; YANG, QUN; ZHOU, JIANPING

doi: 10.1111/j.1095-8339.2001.tb00566.xpmid: N/A

AbstractLeaf cuticle micromorphology of Metasequoia glyptostroboides Hu & W. C. Cheng was studied with SEM using samples collected from its natural population in south-central China and cultivated trees in Nanjing City. The cuticle characters from both natural and cultivated trees living in different environments allowed us to re-evaluate taxonomic values of certain cuticular characters and to assess their relationships with environmental factors and the degree of tree maturity. External and internal cuticular features of both adaxial (upper) and abaxial (lower) leaf surfaces revealed the following: (1) Cuticle micromorphology of M. glyptostroboides is distinct among Taxodiaceae, but that variation does not exceed the range of this family. (2) Except for an isolated tree outside the Metasequoia valley, the cuticular features displayed by individual trees from the main Metasequoia groves demonstrate a high degree of uniformity, which is in congruence with previous observations on the low population variability at the gross morphology level. (3) Cuticular characters of grafted Metasequoia trees living in different environments are identical to those of their original trees, indicating that no cuticular character of this species could be regarded as an environmental indicator. (4) Recognition of some unique cuticular features in a Metasequoia tree in an isolated location may lead to a rare source for increasing the variation of this endangered species.

DAS, ANATH BANDHU; MUKHERJEE, ARUP KUMAR; DAS, PREMANANDA

doi: 10.1111/j.1095-8339.2001.tb00567.xpmid: N/A

AbstractRandom amplified polymorphic DNA (RAPD) markers are used to estimate interspecific variation among mangrove and non-mangrove Heritiera fomes, H. littoralis and H. macrophylla. All the species have 2n = 38 chromosomes, with minute structural changes distinguishing the karyotype of each species. Significant variation of 4C DNA content occurs at the interspecific level. Interspecific polymorphism ranged from 14.09% between H. fomes and H. littoralis to 52.73% between H. fomes and H. macrophylla. H. macrophylla showed wide polymorphism in the RAPD marker with H. littoralis (51.23%) and H. fomes (52.73%). Two distinct RAPD products obtained from OPA-10 (1000 bp) and OPD-15 (900 bp) found characteristic molecular markers in H. macrophylla, a species from a non-mangrove habitat. H. macrophylla was more distantly related to H. fomes [genetic distance (1-F) = 0.305] than to H. littoralis [genetic distance (1-F) = 0.273]. H. littoralis was of a closer affinity to H. fomes [genetic distance (1-F) = 0.218] than to H. macrophylla.

RÔÇAS, G.; SCARANO, F. R.; BARROS, C. F.

doi: 10.1111/j.1095-8339.2001.tb00568.xpmid: N/A

AbstractAlchornea triplinervia (Spreng.) Müll. Arg. (Euphorbiaceae) is a tree which occurs in a broad range of habitats in Brazil. In the State of Rio de Janeiro, it occurs from montane forests to swamplands at sea level. A quantitative approach was used to examine the role of light and soil water regime on the variations found in anatomical traits of the palisade and spongy parenchyma, outer epidermal cell wall of the abaxial and adaxial surfaces, the percentage of sclerenchymatous area in relation to the total midrib area and the ratio of palisade to spongy parenchyma for five distinct ecological populations: M—late secondary montane forest (shaded, unflooded); M2—early secondary montane forest (semi-exposed, unflooded); SI—primary swamp forest (semi-exposed, flooded); S2—secondary swamp forest (exposed, flooded); and D—deforestation area (exposed, unflooded). Tukey tests were carried out for multiple comparisons, while one-way factor variance analysis was used to test for differences among ecological populations. A principal component analysis was used to order the populations as well as to find the higher variance component. These populations developed different response levels to the environmental factors studied, namely light and soil water regime. Light accounted for the variations found in palisade and spongy parenchyma while the combination of light and soil water determined the variations found regarding the outer epidermal cell wall of the abaxial surface, the percentage of sclerenchymatous area in relation to the total midrib area and the compaction of the spongy parenchyma. The separation of S1/M2 and S2/D populations into two groups was due to similar light regimes, which suggested that light was affecting the leaf anatomical variation of A. triplinervia more than the interaction of light and soil water regime.

HUYNH, KIM-LANG

doi: 10.1111/j.1095-8339.2001.tb00569.xpmid: N/A

AbstractIn Sararanga, the fruit is a berry as in Freycinetia. The testa comprises a lignifled outer integument with several cell layers, and an unlignified inner integument with two cell layers. Abortive fruits are frequent; they correspond to normal fruits that do not have carpels and sometimes have a lateral process that suggests an abortive carpel. The staminate flowers have a pistillode as in Freycinetia. The anther walls have 1–3 cell layers with endothecial thickenings, one layer in the distal part, 2–3 layers in the proximal part, as in Pandanus. Thus, within the family Pandanaceae, Sararanga has an intermediate position between Pandanus and Freycinetia. Generally speaking, there is a gradient in the vascularization of the bracts on the inflorescences: upper bracts are unvascularized, lower bracts vascularized. Anatomy suggests that the cupules are a perianth.

RIOS, SEGUNDO; CRESPO, MANUEL B.; RIVERA, DIEGO

doi: 10.1111/j.1095-8339.2001.tb00570.xpmid: N/A

AbstractOrophilous taxa of Sideritis sect. Sideritis (Lamiaceae) are rare, although highly diversified in south-eastern Spain. Most of them belong to subsections Hyssopifolia and Fruticulosa and show very reduced distribution areas in the summits of the highest Betic mountains. The inaccessibility of their habitats has meant that many of them have been described only within the last twenty years. In this context, a new species Sideritis tugiensis is described in subsection Hyssopifolia, from the Oromediterranean summits of Sierra de Segura (south-eastern Spain). It is a woody, cushion-shaped plant, resembling both S. carbonellis Socorro (subsect. Hyssopifolia) and S. glacialis Boiss., s.l. (subsect. Fruticulosa), though important morphological divergences warrant recognition at species rank. Data on morphology, ecology and chorology of the new species are reported, and affinities and differences with regard to close taxa from other subsections are presented. Evolutionary trends in the whole aggregate are briefly discussed.