Enigmatic floral structures in Alternanthera, Iresine, and Tidestromia (Gomphrenoideae, Amaranthaceae). A developmental homology assessment

Vrijdaghs, Alexander; Flores‐Olvera, Hilda; Smets, Erik

doi:10.5091/plecevo.2014.893

Cited by 12 publications

(13 citation statements)

References 22 publications

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“…As in a majority of Amaranthaceae, the flowers possess five lanceolate, ovate or oblong sepals that are free to the base and often are hooded at the apex and have three or five veins. In line with several authors of the German school such as Rohweder (1970), Rohweder & Huber (1974) and Urmi-König (1981), who considered the perianth in Caryophyllales to have lost the corolla and recent ontogenetic findings (Vrijdaghs & al., 2014), we will further call the perianth parts "sepals". The sepals of pistillate and bisexual flowers develop conspicuous white hairs that become up to 2.5 times as long as the flower at maturity serving dispersal of the whole flower as diaspore (Fig.…”

Section: Version Of Recordsupporting

confidence: 81%

“…To the contrary, lateral appendages on each side of a filament are generally present in the gomphrenoid clade (e.g., Borsch & Pedersen, 1997;Townsend, 1993). Filaments are only very shortly fused at the base but the androecial tube possesses appendages alternating with the filaments (androecial tube appendages sensu Vrijdaghs & al. (2014).…”

Section: Version Of Recordmentioning

confidence: 99%

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Pollen characters and DNA sequence data converge on a monophyletic genus Iresine (Amaranthaceae, Caryophyllales) and help to elucidate its species diversity

Borsch

Flores‐Olvera

Zumaya

et al. 2018

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Iresine is a neotropical genus of the Amaranthaceae with most of the species diversity in Mexico and Mesoamerica. It has suffered a complex classification history with considerably diverging views on the genus concept. We have carried out a phylogenetic analysis of Iresine and allied genera using sequence data of combined plastid introns (including the matK CDS) and spacers as well as ITS, and a dense sampling of species. Trees depict a clade of Iresine with Irenella and Woehleria deeply nested. This clade is sister to the remainder of Gomphrenoideae including Hebanthe and Trommsdorffia (≡ Pedersenia). One of two maximally supported subclades of Iresine comprises mostly species restricted to the Mexican highlands and adjacent areas, whereas the other subclade is composed of more widespread Mexican‐Mesoamerican taxa. Pollen grains of Iresine and relatives were examined using high‐resolution SEM, which yielded a matrix of 15 pollen characters. Ancestral character state reconstruction shows dodecahedral grains (in I. angustifolia and I. nigra) to have evolved within the Iresine clade, not involving the complete suite of character shifts associated with metareticulate pollen but just an increase of aperture diameter and a slight decrease of mesoporia width. To the contrary, four character state transformations occurred in the common ancestor of core Gomphrenoideae that led to metareticulate pollen (shifts to a distal orientation of punctae and microspines, to a sunken position of apertures relative to the distal part of mesoporia resulting in narrow mesoporia higher then wide, and a reduction in the diameter of mesoporia). The Iresine clade is characterized by pollen with well‐separated ektexinous aperture membrane bodies, rounded or triangular, and gradually tapering into a single spine. For the monophyletic genus Iresine, 35 species are currently accepted. We provide a taxonomic backbone (including one new combination, one new name and several lectotypifications) that also comments on the current understanding of species delimitation.

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Section: Version Of Recordsupporting

confidence: 81%

Section: Version Of Recordmentioning

confidence: 99%

Pollen characters and DNA sequence data converge on a monophyletic genus Iresine (Amaranthaceae, Caryophyllales) and help to elucidate its species diversity

Borsch

Flores‐Olvera

Zumaya

et al. 2018

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1,311

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“…Schinz (as Alternanthera microcephala (Moq.) Schinz) (Vrijdaghs, Flores‐Olvera & Smets, , fig. 6D, E); Amaranthus paniculatus L. (Pankow, , figs 83, 84, 86); Beta trigyna Waldst.…”

Section: Resultsmentioning

confidence: 99%

“…& Hook.f.) (Vrijdaghs et al ., , figs 3F–H, 8D); Pleuropetalum darwinii Hook.f. (Ronse Decraene, Volgin & Smets, , figs 19–22); Salicornia europaea L. (Beer, Beer & Sokoloff, , fig.…”

Section: Resultsmentioning

confidence: 99%

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Patterns of angiospermy development before carpel sealing across living angiosperms: diversity, and morphological and systematic aspects

Endress

2015

Bot J Linn Soc

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Almost all angiosperms are angiospermous, i.e. the ovules are enclosed in carpels at anthesis and during seed development, but angiospermy develops in different ways across angiosperms. The most common means of carpel closure is by a longitudinal ventral slit in carpels that are partly or completely free. In such carpels, the closure process commonly begins at midlength of the prospective longitudinal slit and then proceeds downward and upward. Closure by a transverse slit is rarer, but it is prominent in groups of the ANITA grade and in a few early branching monocots (some Alismatales) and some early branching eudicots (a few Ranunculaceae and Nelumbonaceae), in these eudicots combined with a more or less developed longitudinal slit. In all these cases the carpels have a single ovule in ventral median position. In ANITA lines with pluriovulate carpels, there is only a short longitudinal slit in the uniformly ascidiate carpels. In carpels with a unifacial style the closure area is narrow; this pattern is rare and scattered mainly in some wind-pollinated monocots and eudicots. In most angiosperms the carpels become closed before the ovules are visible from the outside of the still incompletely closed carpels (early carpel closure). This is notably the case in the ANITA grade and magnoliids. Delayed carpel closure, with the ovules visible before the carpels are closed, is much rarer and is concentrated in a few monocots (mainly some Alismatales and some Poales) and a few eudicots (mainly a few Ranunculales and many Caryophyllales, and scattered in some other eudicots). A kind of delayed carpel closure (with the placenta visible before closure but mostly not the ovules) also occurs in syncarpous gynoecia with a free central placenta. Most gynoecia with a free central placenta occur in the superasterids. In such gynoecia the individual carpel tips are not differentiated but the opening in young gynoecia has the shape of a circular diaphragm. In this case, when ovary septa and free carpel tips are missing, the number of carpels is sometimes unclear (Primulaceae, Lentibulariaceae, some Santalaceae). Extremely ascidiate carpels are concentrated in the ANITA grade, a few magnoliids and some early branching monocots. Aspects of potential advantages of plicate vs. ascidiate carpels with regard to flexibility of pollen tube transmitting tract differentiation are discussed.

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Phylogenetics and morphological character evolution in the achyranthoid clade (Amaranthaceae): Evidence to re‐circumscribe the genera Achyranthes and Cyathula and to resurrect a third species of the former genus Sericocomopsis in East Africa

Di Vincenzo,

Berendsohn,

Wondafrash

et al. 2024

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The achyranthoid clade constitutes the second most species‐rich lineage of the Amaranthaceae after the gomphrenoid clade. The Achyranthoids are mostly African, in contrast to the largely Neotropical Gomphrenoids, and comprise a large number of genera, many of which were revealed as non‐monophyletic. Here were focus on subclade II of the Achyranthoids with the so far accepted genera Achyranthes, Achyropsis, Centrostachys, Cyathula, Nelsia, Nototrichium, Pandiaka, Sericocomopsis, and Sericostachys. Building upon an earlier dataset, we extended taxon and character sampling, both for molecular and morphological characters. Our plastid and nuclear trees converge on several highly supported clades, one comprising most species of Cyathula, Nelsia, Pandiaka and two highly divergent lineages of plants hitherto identified as Sericocomopsis hildebrandtii. Morphologically, individuals within these lineages are similar, with one of them matching the type of Sericocomopsis meruensis. This name was formerly considered a synonym and is resurrected at species level. Cymous partial florescences are ancestral in this clade, which corresponds to the genus Cyathula as re‐circumscribed here. To the contrary, sterile flowers and bracteoles or tepals modified to hooks serving dispersal by animals appear multiple times within and outside this clade, indicating how their use as diagnostic characters for genera led to non‐monophyletic entities. For the phylogenetically isolated and morphologically distinct Cyathula orthacantha the new genus Sebsebea is described, and for Sericocomopsis pallida the new genus Evelynastra. The Achyranthes clade is characterized by solitary, fertile flowers including the genera Achyropsis and Nototrichium both of which are merged to make Achyranthes monophyletic. In addition to a treatment to establish all required nomenclatural changes and typifications, we also provide a taxonomic backbone with full synonymy for the achyranthoid subclade II.

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Enigmatic floral structures in Alternanthera, Iresine, and Tidestromia (Gomphrenoideae, Amaranthaceae). A developmental homology assessment

Cited by 12 publications

References 22 publications

Pollen characters and DNA sequence data converge on a monophyletic genus Iresine (Amaranthaceae, Caryophyllales) and help to elucidate its species diversity

Pollen characters and DNA sequence data converge on a monophyletic genus Iresine (Amaranthaceae, Caryophyllales) and help to elucidate its species diversity

Patterns of angiospermy development before carpel sealing across living angiosperms: diversity, and morphological and systematic aspects

Phylogenetics and morphological character evolution in the achyranthoid clade (Amaranthaceae): Evidence to re‐circumscribe the genera Achyranthes and Cyathula and to resurrect a third species of the former genus Sericocomopsis in East Africa

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