Topic
Stylidium
About: Stylidium is a research topic. Over the lifetime, 64 publications have been published within this topic receiving 1140 citations.
Papers published on a yearly basis
Papers
TL;DR: This study studied the pollination ecology and assemblage structure of 31 species of Stylidium at 25 sites in Western Australia and indicated that character displacement has probably occurred, one of the clearest demonstrations to date of reproductive inter-species interactions.
Abstract: We studied the pollination ecology and assemblage structure of 31 species of Stylidium (Stylidiaceae) at 25 sites in Western Australia. The number of species per study site varied between two and six. Stylidium species are pollinated by a variety of nectar-seeking solitary bees and bombyliid flies. Within and among species there is sig- nificant variation in nectar-tube length (and therefore in the insects that visit the flowers) and in pollen placement on pollinators. Pollen is placed "explosively" on the insect by a motile column of fused staminate and pistillate tissues; the position and reach of the column varies within and among species, thereby causing variation in site of pollen deposition. When discrete pollination niches were defined for all species, only one niche overlap was observed across the 86 interacting pairs of Stylidium species at the 25 sites. To determine whether this was a nonrandom assemblage structure we compared our observation with the outcome of null models. We developed three null models to cover the most likely structuring processes: that communities are organized by (1) ecological sorting, (2) evolution of plant phenotypes, or (3) both processes. We concluded that it was unlikely (P = .055- .002) that so few overlaps in pollination niches would occur by chance. We developed another null model to test whether chance could have created the apparent pattern of character displacement in pollination niches exhibited by the nine species showing intra- specific variation. The analysis indicated that character displacement has probably occurred (P = .014). This study is one of the clearest demonstrations to date of reproductive inter-
287 citations
TL;DR: It is suggested here that the correlation between clade species richness and floral specialization is real, but that cladespecies richness is frequently the cause, not the result of floral specialization, and that reproductive character-displacement hypothesis seems likely to be more important for plant groups with less precise pollination systems.
Abstract: It has been proposed frequently, from Darwin’s time onwards, that specialized pollination increases speciation rates and thus the diversity of plant species (i.e. clade species richness). We suggest here that the correlation between clade species richness and floral specialization is real, but that clade species richness is frequently the cause, not the result of floral specialization. We urge a broader, variance-partitioning perspective for assessing the causes of this correlation by suggesting four models of how the diversity-specialization correlation might come about: (1) floral specialization promotes initial reproductive isolation (“Initial-RI” model), (2) floral specialization promotes reinforcement of reproductive isolation upon secondary contact (“Reinforcement” model), (3) floral specialization reduces the extinction rate by promoting tighter species packing (“Extinction” model), (4) floral specialization is the result of high clade species richness, which increases the number of related species in communities, and thus selects for floral character displacement (“Character-Displacement” model). These hypotheses are evaluated by comparing the relationships between species richness, speciation mechanisms, and pollination precision, accuracy, and specialization in the broader literature and, more specifically, in four study systems: Dalechampia (Euphorbiaceae), Collinsia (Plantaginaceae), Burmeistera (Campanulaceae), and Stylidium (Stylidiaceae). These systems provide stronger support for the character-displacement hypothesis, wherein local species diversity drives the evolution of specialized pollination. Although the two reproductive-isolation hypotheses may hold for plants like orchids, with extremely precise pollination systems, the reproductive character-displacement hypothesis seems likely to be more important for plant groups with less precise pollination systems.
191 citations
TL;DR: Besides species of Eucalyptus, Leptospermum, Casuarina and Pomaderris, many other Australian native plants may form ectomycorrhizal associations, which range from large forest trees to small non-woody herbs.
Abstract: SUMMARY Besides species of Eucalyptus, Leptospermum, Casuarina and Pomaderris which are known to form ectomycorrhizas, many other Australian native plants may form ectomycorrhizal associations. The plants include many legumes, especially in the tribe Podalyrieae of the Fabaceae and Acacia in the Mimosaceae, all members of the Rhamnaceae examined, and species of such diverse genera as Opercularia, Poranthera, Platysace, Goodenia and Stylidium. Many, perhaps most, of these ectomycorrhizal plants may also form endomycorrhizas of the VA type. The ectomycorrhizal species range from large forest trees to small non-woody herbs. The associations vary from well-defined mycorrhizas of the beech type to looser ones of a continuous or partial sheath, with or without a Hartig net. In soil low in available phosphate both typical and looser ectomycorrhizal associations markedly increased plant growth compared with that of uninoculated plants.
113 citations
TL;DR: The various angiosperm clades in which carnivory has evolved and the degree to which these plants have become ‘complete carnivores’ is documented and the problems with definition of the terms used to describe carnivorous plants are discussed.
83 citations
TL;DR: It is hypothesized that pollination efficiency selects for equal distances between the pollinator reward and the anthers, and the stigmas, creating an adaptive ridge, and predicts that this fitness surface governs the divergence of many plant species.
Abstract: Summary • We hypothesize that pollination efficiency selects for equal distances between the pollinator reward and the anthers, and the stigmas, creating an adaptive ridge We predict that this fitness surface governs the divergence of many plant species We use the theory of adaptive accuracy, precision and mean optimality to assess how close populations lie to the hypothesized adaptive ridge and which factors contribute to departure from the optimum Patterns of accuracy of pollen placement and receipt were compared across species in three study systems, Dalechampia (Euphorbiaceae), Collinsieae (Plantaginaceae) and Stylidium (Stylidiaceae), in order to assess the roles of stamen/stigma imprecision and population mean departure from the optimum in the generation of floral inaccuracy We found that population mean departure from the optimum was the most important factor in Dalechampia, female imprecision and departure from the optimum were about equally important factors in Collinsieae, and stamen and stigma imprecision were equally important in Stylidium, with virtually no departure from the optimum Possible reasons for imprecision and departure from the optimum were assessed using phylogenetically informed methods, indicating important roles of limited floral integration in the generation of imprecision, and conflicting selective pressures, associated with outcrossing, in the generation of departure from the optimum
62 citations
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Performance Metrics
| Year | Papers |
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| 2021 | 1 |
| 2019 | 1 |
| 2018 | 1 |
| 2017 | 1 |
| 2015 | 1 |
| 2014 | 1 |