| 1. |
- Borg, Agneta Julia, et al.
(författare)
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Comparative floral development and structure of the black mangrove genus Avicennia L. and related taxa in the Acanthaceae
- 2011
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 172:3, s. 330-344
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Tidskriftsartikel (refereegranskat)abstract
- Phylogenetic relationships of Avicennia have been difficult to trace because of the presence of convergent characters related to the mangrove environment. Recent molecular data suggest a close relationship to Thunbergioideae, a subfamily within Acanthaceae (Lamiales), but morphological support for the new findings has been equivocal. Floral structure and development are comparatively studied here in three species of Avicennia, with special attention given to the ovary and the ovules, which are also studied in Thunbergioideae. The suggested sister group relationship of Avicennia and Thunbergioideae is supported by three synapomorphies: (1) collateral ovule arrangement, (2) vertical orientation of ovule curvature, and (3) an exposed nucellus that is contiguous with the ovary wall, at least during early stages of ovule development. We interpret the latter character as a neotenic feature that is retained in the anthetic ovules of Avicennia. We confirm that the apparently tetramerous flowers of Avicennia have a basically pentamerous floral ground plan. Additional floral characters shared between Avicennia and Thunbergioideae include left contort corolla aestivation, thickened filament bases with glandular hairs, presence of pollen sac placentoids, and various aspects of fruit morphology and embryology. However, these features are either symplesiomorphic or are not known well enough to allow for unequivocal conclusion on character evolution in Acanthaceae.
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| 2. |
- Falster, Daniel, et al.
(författare)
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AusTraits, a curated plant trait database for the Australian flora
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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| 3. |
- Schoenenberger, Juerg
(författare)
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Comparative floral structure and systematics of fouquieriaceae and polemoniaceae (ericales)
- 2009
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 170:9, s. 1132-1167
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Forskningsöversikt (refereegranskat)abstract
- Floral morphology, anatomy, and histology are comparatively studied in Fouquieriaceae and Polemoniaceae, and previous studies are reviewed. In recent molecular phylogenetic analyses, the two families form a strongly supported clade within the asterid order Ericales, while they were generally placed far from each other in premolecular classifications. This study documents unexpectedly diverse floral features for Polemoniaceae, including various corolla aestivation patterns, different types of anther attachment and anther morphology, as well as two types of nectary structure. Prominent features shared by the two families include determinate-terminal inflorescences, hyaline sepal margins, similar patterns of floral vasculature, late sympetalous corolla development, similar degrees of sympetaly, sterile connective protrusions, short thecal septa, endothecium-like cells in the connective, trimery in the gynoecium, a stylar canal, parietal, and axile and placentation in the same ovary, similar patterns of ovule arrangement and ovule orientation, distally curved micropylar canals, mesophyll-type nectaries with stomata, winged seeds, and seed coat epidermal cells with helical or annular wall thickenings. Several of these features represent potential synapomorphies for the clade with Fouquieriaceae and Polemoniaceae. In addition, potential synapomorphies are also identified for the individual families. While the results of this investigation further support the close relationship of Polemoniaceae and Fouquieriaceae, they also emphasize that it is necessary to abandon preconceptions about the ""systematic importance"" of certain characters that turn out to be more homoplasious than previously thought.
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| 4. |
- von Balthazar, Maria, et al.
(författare)
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Floral Structure and Organization in Platanaceae
- 2009
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 170:2, s. 210-225
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Tidskriftsartikel (refereegranskat)abstract
- Developing and mature inflorescences and flowers of several representatives of Platanus were studied to clarify various aspects of floral structure and organization. Special attention was given to perianth differentiation. Extant Platanaceae are monoecious with unisexual flowers aggregated into compact, spherical inflorescence heads. Development of hairs in a basipetal direction subdivides the undifferentiated inflorescence surface into floral zones. Development of both male and female flowers of Platanus 3 hispanica begins with the initiation of a perianth whorl. Thereafter, the reproductive organs emerge on the floral apex: stamens in male flowers, staminodes and carpels in female flowers. The last organs to appear in both sexes are the small organs located between perianth and androecium. At anthesis, in both male and female flowers, organs of the first whorl are inconspicuous, scalelike, and only two to three cell layers thick. Alternating with these first thin organs is a whorl of short but fleshy organs. These second-whorl organs are basally united with the stamens, forming a short androecial tube. They also show some structural similarities with stamens. These features support the hypothesis that the second-whorl organs are of androecial (staminodial) origin. This hypothesis is further supported by the fossil record, where, in some taxa, second-whorl organs are particularly similar to stamens, as well as by morphological comparisons with flowers of Proteaceae.
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