Zusammenfassung Seit einigen Jahren befinden sich Rapshalbzwerghybride auch im praktischen Anbau... more Zusammenfassung Seit einigen Jahren befinden sich Rapshalbzwerghybride auch im praktischen Anbau. Zu deren Verhalten gegenüber Unkräutern gibt es bisher nur wenige Studien. Seit einigen Jahren sind zudem zunehmend schwer zu bekämpfende Problemunkräuter in Rapsbeständen zu beobachten. Daher wurden Anchusa arvensis (L.) M. Bieb., Sisymbrium officinale (L.) Scop. und drei verschiedene Geranium-Arten ausgewählt, um deren Entwicklung, Samenbildung und Biomasse zu untersuchen und mögliche Auswirkungen auf Rapszhalbwerghybride abzuleiten. Für die Versuche wurden drei unterschiedlich hohe Rapssorten verwendet: „Viking“, der Halbzwerg „PR45D01“ und eine Zwergzuchtlinie. Im Vergleich zu normalwüchsigen Rapssorten werden in Halbzwergbeständen besonders lichtbedürftige und hochwüchsige Unkräuter gefördert, die gesteigerte Biomasseproduktion und höheren Samenansatz pro Pflanze zeigen.
ABSTRACT Plants that trap and eat animals have inspired awe since before the days of Darwin. Lure... more ABSTRACT Plants that trap and eat animals have inspired awe since before the days of Darwin. Lured into the danger zone by optical, tactile, and olfactory strategies, the prey succumb to ingenious traps and face their doom. But unlike plants that temporarily catch insects for pollination, the true carnivores go considerably further: they digest them for the nutrients they need to survive in extremely inhospitable sites on land and in water. This exquisite, thoroughly up-to-date book, copiously illustrated with closeup photography, provides the first comprehensive listing of some 630 known carnivorous plant species, described in fascinating detail, with identification history, physiology, ecology, and an extensive bibliography. It is an essential reference for hobbyist, naturalist, and collector alike.
Some 450 species of insectivorous plants have been discovered since Darwin published his work on ... more Some 450 species of insectivorous plants have been discovered since Darwin published his work on the subject in 1875. We report here the first known case of a plant that traps and digests protozoa.
Inselbergs are monolithic, old and stable landscape elements with a worldwide distribution. On in... more Inselbergs are monolithic, old and stable landscape elements with a worldwide distribution. On inselbergs, relatively old (i.e. hundreds of years old) rock pools form a unique habitat that offers locally wet conditions in an otherwise edaphically and microclimatically dry environment. They occur as seasonally water-filled depressions with a thin layer of soil, and are mainly inhabited by ephemerals and cryptogams. Even during the rainy season, they often become dry if precipitation is lacking for a few days. Between 1990 and 1999, about 200 rock pools in the Ivorian savanna zone were examined on a regular basis. Absolute and relative turnover rates were calculated: values ranged from 0.00 to 3.00 and 0 to 78%, respectively. Mean turnover was 0.19 (17%). The turnover in the SRPs increased significantly with soil depth and area. No correlation was found between turnover and species number of the pools, which increased significantly with area. The highest turnover was shown by the annu...
The vegetation of shallow depressions on Ivorian granite inselbergs was studied along a gradient ... more The vegetation of shallow depressions on Ivorian granite inselbergs was studied along a gradient from the savanna zone in the north to the rainforest zone in the south of the country. Short-term inundation and prolonged drought are typical features of this habitat. In total, 64 taxa belonging to 25 families were recorded, with the Poaceae, Cyperaceae and Fabaceae accounting for
Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosper... more Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosperms, with the smallest established 1C-value of 157 Mbp recorded in Arabidopsis thaliana. In the highly specialized carnivorous family Lentibulariaceae now three taxa have been found that exhibit significantly lower values: Genlisea margaretae with 63 Mbp, G. aurea with 64 Mbp, and Utricularia gibba with 88 Mbp. The smallest mitotic anaphase chromatids in G. aurea have 2.1 Mbp and are thus of bacterial size (NB: E. coli has ca. 4 Mbp). Several Utricularia species range somewhat lower than A. thaliana or are similar in genome size. The highest 1C-value known from species of Lentibulariaceae was found in Genlisea hispidula with 1510 Mbp, and results in about 24-fold variation for Genlisea and the Lentibulariaceae. Taking into account these new measurements, genome size variation in angiosperms is now almost 2000-fold. Genlisea and Utricularia are plants with terminal positions in the phylogeny of the eudicots, so that the findings are relevant for the understanding of genome miniaturization. Moreover, the Genlisea-Utricularia clade exhibits one of the highest mutational rates in several genomic regions in angiosperms, what may be linked to specialized patterns of genome evolution. Ultrasmall genomes have not been found in Pinguicula, which is the sister group of the Genlisea-Utricularia clade, and which does not show accelerated mutational rates. C-values in Pinguicula varied only 1.7-fold from 487 to 829 Mbp.
ABSTRACT This study describes xeric saxicolous plant communities of inselbergs embedded in a sava... more ABSTRACT This study describes xeric saxicolous plant communities of inselbergs embedded in a savannah matrix (in West Africa) and of inselbergs embedded in rainforest (in Atlantic central Africa). We looked at how the species' socio-ecology and distribution differ according to the different matrix vegetation. TWINSPAN-classification of 188 phytosociological relevés defined three plant communities all dominated by the poikilohydric mat-forming sedge Afrotrilepis pilosa. Besides this Cyperaceae, the communities in West Africa and Atlantic central Africa share only one species. Two new associations are described: Cyanotido lanatae-Afrotrilepidetum pilosae on West African inselbergs and Oreonesiono testui-Afrotrilepidetum pilosae on inselbergs from Atlantic central Africa. Each of them typifies a new alliance included in a new order. This new order typifies a new class: Afrotrilepidetea pilosae. Therophytes occurs with many species in Cyanotido lanatae-Afrotrilepidetum pilosae while chamaephytes are most abundant in Oreonesiono testui-Afrotrilepidetum pilosae. The flora of inselbergs surrounded by savannah is characterized by species largely distributed in tropical Africa (60%). Most species occur also in the matrix surrounding the inselbergs, only one being strictly confined to the inselberg habitat. On inselbergs embedded in rainforest 40 % of the species originate from the Lower Guinea sub-center of endemism. Nine species are only known to grow in the inselberg habitat. Mantel tests of correlation between floristic, climatic and spatial distances were computed in the two contrasted situations (savannah and rainforest matrix). For rainforest inselbergs the floristic dissimilarity is positively correlated to the spatial and climatic distances, while there was no significant correlation for savannah inselbergs. In our data set, the flora of inselbergs embedded in a savannah matrix was thus more uniform than that of inselbergs surrounded by rainforest.
ABSTRACT Inselbergs of the Atlantic rainforest zone in south-eastern Brazil typically appear blac... more ABSTRACT Inselbergs of the Atlantic rainforest zone in south-eastern Brazil typically appear black because of the presence of a dense cyanobacterial film. We investigated this autotrophic, microorganism covering on the exposed rock surfaces of five selected inselbergs along a latitudinal gradient, from Parati Mirim in the south to Serra dos Amores in the north. The biofilm was 0.1-0.5 mm thick and consisted mainly of cyanobacteria and rarely cyanobacterial lichens, together with a few filamentous deuteromycete fungi. The biofilm itself was stratified, consisting of three strata: (1) an endolithic stratum, with chasmolithic Chroococcidiopsis sp. and Gloeocapsa sanguinea; (2) an epilithic understorey layer with unicellular forms like G. sanguinea and Xenotholos kerneri; and (3) an upper epilithic layer, composed of filamentous cyanobacteria like Scytonema myochrous, S. ocellatum, Stigonema mamillosum and S. hormoides. In total, 16 species of cyanobacteria, belonging to eight different genera were found on exposed rock surfaces uninfluenced by higher vegetation. The unicellular forms G. sanguinea and X. kerneri and the filamentous cyanobacterium Scytonema ocellatum were the most frequent species. When compared with the cyanobacterial flora of inselbergs in Venezuela, French Guyana and Ivory Coast, the Brazilian inselbergs showed the greatest similarities to those of Venezuela.
... Introduction Link (1824) was the first to observe the specialized epidermis of orchid roots... more ... Introduction Link (1824) was the first to observe the specialized epidermis of orchid roots which was named velamen radicuml'by Schleiden (1842-1843). ... For a survey of literature we refer to the excellent recent review by Pridgeon (1987). ...
ABSTRACT Roots of tree-like Cyperaceae (Afrotrilepis pilosa, Bulbostylis leucostachya, Coleo-chlo... more ABSTRACT Roots of tree-like Cyperaceae (Afrotrilepis pilosa, Bulbostylis leucostachya, Coleo-chloa setifera, Microdracoides squamosus) and Velloziaceae (Vellozia variegata, Xe-rophyta pinifolia) were examined by light and scanning electron microscopy. For the first time a velamen is reported for Bromeliiflorae and Commeliniflorae. All species studied possess a velamen radicum that is either one-layered (Microdracoides, Bulbostylis, Coleochloa) or multi-layered (Afrotrilepis, Vellozia, Xerophyta). Anticlinal walls of the velamen cells of Microdracoides show perforations similar to those found in orchids. A multiple exodermis delimits the velamen towards the cortex. As in epiphytic Orchidaceae, a velamen may be of considerable adaptive value for arborescent Cyperaceae and Velloziaceae. These mainly occur in edaphically and climatologically extreme habitats (e.g. tropical inselbergs) where rapid water uptake is of crucial importance.
Zusammenfassung Seit einigen Jahren befinden sich Rapshalbzwerghybride auch im praktischen Anbau... more Zusammenfassung Seit einigen Jahren befinden sich Rapshalbzwerghybride auch im praktischen Anbau. Zu deren Verhalten gegenüber Unkräutern gibt es bisher nur wenige Studien. Seit einigen Jahren sind zudem zunehmend schwer zu bekämpfende Problemunkräuter in Rapsbeständen zu beobachten. Daher wurden Anchusa arvensis (L.) M. Bieb., Sisymbrium officinale (L.) Scop. und drei verschiedene Geranium-Arten ausgewählt, um deren Entwicklung, Samenbildung und Biomasse zu untersuchen und mögliche Auswirkungen auf Rapszhalbwerghybride abzuleiten. Für die Versuche wurden drei unterschiedlich hohe Rapssorten verwendet: „Viking“, der Halbzwerg „PR45D01“ und eine Zwergzuchtlinie. Im Vergleich zu normalwüchsigen Rapssorten werden in Halbzwergbeständen besonders lichtbedürftige und hochwüchsige Unkräuter gefördert, die gesteigerte Biomasseproduktion und höheren Samenansatz pro Pflanze zeigen.
ABSTRACT Plants that trap and eat animals have inspired awe since before the days of Darwin. Lure... more ABSTRACT Plants that trap and eat animals have inspired awe since before the days of Darwin. Lured into the danger zone by optical, tactile, and olfactory strategies, the prey succumb to ingenious traps and face their doom. But unlike plants that temporarily catch insects for pollination, the true carnivores go considerably further: they digest them for the nutrients they need to survive in extremely inhospitable sites on land and in water. This exquisite, thoroughly up-to-date book, copiously illustrated with closeup photography, provides the first comprehensive listing of some 630 known carnivorous plant species, described in fascinating detail, with identification history, physiology, ecology, and an extensive bibliography. It is an essential reference for hobbyist, naturalist, and collector alike.
Some 450 species of insectivorous plants have been discovered since Darwin published his work on ... more Some 450 species of insectivorous plants have been discovered since Darwin published his work on the subject in 1875. We report here the first known case of a plant that traps and digests protozoa.
Inselbergs are monolithic, old and stable landscape elements with a worldwide distribution. On in... more Inselbergs are monolithic, old and stable landscape elements with a worldwide distribution. On inselbergs, relatively old (i.e. hundreds of years old) rock pools form a unique habitat that offers locally wet conditions in an otherwise edaphically and microclimatically dry environment. They occur as seasonally water-filled depressions with a thin layer of soil, and are mainly inhabited by ephemerals and cryptogams. Even during the rainy season, they often become dry if precipitation is lacking for a few days. Between 1990 and 1999, about 200 rock pools in the Ivorian savanna zone were examined on a regular basis. Absolute and relative turnover rates were calculated: values ranged from 0.00 to 3.00 and 0 to 78%, respectively. Mean turnover was 0.19 (17%). The turnover in the SRPs increased significantly with soil depth and area. No correlation was found between turnover and species number of the pools, which increased significantly with area. The highest turnover was shown by the annu...
The vegetation of shallow depressions on Ivorian granite inselbergs was studied along a gradient ... more The vegetation of shallow depressions on Ivorian granite inselbergs was studied along a gradient from the savanna zone in the north to the rainforest zone in the south of the country. Short-term inundation and prolonged drought are typical features of this habitat. In total, 64 taxa belonging to 25 families were recorded, with the Poaceae, Cyperaceae and Fabaceae accounting for
Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosper... more Nuclear holoploid genome sizes (C-values) have been estimated to vary about 800-fold in angiosperms, with the smallest established 1C-value of 157 Mbp recorded in Arabidopsis thaliana. In the highly specialized carnivorous family Lentibulariaceae now three taxa have been found that exhibit significantly lower values: Genlisea margaretae with 63 Mbp, G. aurea with 64 Mbp, and Utricularia gibba with 88 Mbp. The smallest mitotic anaphase chromatids in G. aurea have 2.1 Mbp and are thus of bacterial size (NB: E. coli has ca. 4 Mbp). Several Utricularia species range somewhat lower than A. thaliana or are similar in genome size. The highest 1C-value known from species of Lentibulariaceae was found in Genlisea hispidula with 1510 Mbp, and results in about 24-fold variation for Genlisea and the Lentibulariaceae. Taking into account these new measurements, genome size variation in angiosperms is now almost 2000-fold. Genlisea and Utricularia are plants with terminal positions in the phylogeny of the eudicots, so that the findings are relevant for the understanding of genome miniaturization. Moreover, the Genlisea-Utricularia clade exhibits one of the highest mutational rates in several genomic regions in angiosperms, what may be linked to specialized patterns of genome evolution. Ultrasmall genomes have not been found in Pinguicula, which is the sister group of the Genlisea-Utricularia clade, and which does not show accelerated mutational rates. C-values in Pinguicula varied only 1.7-fold from 487 to 829 Mbp.
ABSTRACT This study describes xeric saxicolous plant communities of inselbergs embedded in a sava... more ABSTRACT This study describes xeric saxicolous plant communities of inselbergs embedded in a savannah matrix (in West Africa) and of inselbergs embedded in rainforest (in Atlantic central Africa). We looked at how the species' socio-ecology and distribution differ according to the different matrix vegetation. TWINSPAN-classification of 188 phytosociological relevés defined three plant communities all dominated by the poikilohydric mat-forming sedge Afrotrilepis pilosa. Besides this Cyperaceae, the communities in West Africa and Atlantic central Africa share only one species. Two new associations are described: Cyanotido lanatae-Afrotrilepidetum pilosae on West African inselbergs and Oreonesiono testui-Afrotrilepidetum pilosae on inselbergs from Atlantic central Africa. Each of them typifies a new alliance included in a new order. This new order typifies a new class: Afrotrilepidetea pilosae. Therophytes occurs with many species in Cyanotido lanatae-Afrotrilepidetum pilosae while chamaephytes are most abundant in Oreonesiono testui-Afrotrilepidetum pilosae. The flora of inselbergs surrounded by savannah is characterized by species largely distributed in tropical Africa (60%). Most species occur also in the matrix surrounding the inselbergs, only one being strictly confined to the inselberg habitat. On inselbergs embedded in rainforest 40 % of the species originate from the Lower Guinea sub-center of endemism. Nine species are only known to grow in the inselberg habitat. Mantel tests of correlation between floristic, climatic and spatial distances were computed in the two contrasted situations (savannah and rainforest matrix). For rainforest inselbergs the floristic dissimilarity is positively correlated to the spatial and climatic distances, while there was no significant correlation for savannah inselbergs. In our data set, the flora of inselbergs embedded in a savannah matrix was thus more uniform than that of inselbergs surrounded by rainforest.
ABSTRACT Inselbergs of the Atlantic rainforest zone in south-eastern Brazil typically appear blac... more ABSTRACT Inselbergs of the Atlantic rainforest zone in south-eastern Brazil typically appear black because of the presence of a dense cyanobacterial film. We investigated this autotrophic, microorganism covering on the exposed rock surfaces of five selected inselbergs along a latitudinal gradient, from Parati Mirim in the south to Serra dos Amores in the north. The biofilm was 0.1-0.5 mm thick and consisted mainly of cyanobacteria and rarely cyanobacterial lichens, together with a few filamentous deuteromycete fungi. The biofilm itself was stratified, consisting of three strata: (1) an endolithic stratum, with chasmolithic Chroococcidiopsis sp. and Gloeocapsa sanguinea; (2) an epilithic understorey layer with unicellular forms like G. sanguinea and Xenotholos kerneri; and (3) an upper epilithic layer, composed of filamentous cyanobacteria like Scytonema myochrous, S. ocellatum, Stigonema mamillosum and S. hormoides. In total, 16 species of cyanobacteria, belonging to eight different genera were found on exposed rock surfaces uninfluenced by higher vegetation. The unicellular forms G. sanguinea and X. kerneri and the filamentous cyanobacterium Scytonema ocellatum were the most frequent species. When compared with the cyanobacterial flora of inselbergs in Venezuela, French Guyana and Ivory Coast, the Brazilian inselbergs showed the greatest similarities to those of Venezuela.
... Introduction Link (1824) was the first to observe the specialized epidermis of orchid roots... more ... Introduction Link (1824) was the first to observe the specialized epidermis of orchid roots which was named velamen radicuml'by Schleiden (1842-1843). ... For a survey of literature we refer to the excellent recent review by Pridgeon (1987). ...
ABSTRACT Roots of tree-like Cyperaceae (Afrotrilepis pilosa, Bulbostylis leucostachya, Coleo-chlo... more ABSTRACT Roots of tree-like Cyperaceae (Afrotrilepis pilosa, Bulbostylis leucostachya, Coleo-chloa setifera, Microdracoides squamosus) and Velloziaceae (Vellozia variegata, Xe-rophyta pinifolia) were examined by light and scanning electron microscopy. For the first time a velamen is reported for Bromeliiflorae and Commeliniflorae. All species studied possess a velamen radicum that is either one-layered (Microdracoides, Bulbostylis, Coleochloa) or multi-layered (Afrotrilepis, Vellozia, Xerophyta). Anticlinal walls of the velamen cells of Microdracoides show perforations similar to those found in orchids. A multiple exodermis delimits the velamen towards the cortex. As in epiphytic Orchidaceae, a velamen may be of considerable adaptive value for arborescent Cyperaceae and Velloziaceae. These mainly occur in edaphically and climatologically extreme habitats (e.g. tropical inselbergs) where rapid water uptake is of crucial importance.
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