Tagged: angiosperms


Glorious global gambol through the plants

Around the World in 80 Plants by Jonathan Drori 2021. Laurence King Publishing Ltd. In my review of Jonathan Drori’s Around the World in 80 Trees [‘80 Trees’], I suggested there were many more tree species worthy of being celebrated in such a book (or books). Whilst I don’t know if my comments influenced the author in any way, I’m very pleased to see that Drori has produced a follow-up to that 2018 work. Although this new book, entitled Around the World in 80 Plants* [and which is here appraised as 80 Plants], extends the author’s admiration for plants beyond...

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Ovule and seed production patterns in relation to flower size and floral symmetry

Animal pollinated flowers show two types of floral symmetry, actinomorphy (radial symmetry) with several planes of symmetry or zygomorphy (bilateral symmetry) with just one symmetry plane. Although these floral types evolved separately, to a large degree they show functionally similar pollination patterns. However, zygomorphic flowers are often visited by a narrower range of pollinator groups. This may be because zygomorphic flowers often have complex structures to which only certain pollinators can respond. Actinomorphic flowers, on the other hand, have more simple structures that many pollinator groups can visit. This has resulted in zygomorphic species showing less variation in flower size...

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Many coloured bands

Patterns of sex expression, health and mortality in a sex-changing tree

The ability of individuals to change sex during their lifetime is known as environmental sex determination (ESD). This ability represents a unique life history trait, allowing plants to allocate resources differentially to male and female functions across lifetimes, potentially maximizing fitness in response to changing environmental or internal cues. Blake-Mahmud and Struwe investigated Acer pensylvanicum, a species with an unconfirmed sex determination system, to see what patterns in sex expression existed across multiple years, if there were sex-based differences in growth and mortality, and whether this species conformed to theoretical predictions that females are larger and in better condition. In...

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Flowers

Thirty clues to the exceptional diversification of flowering plants

As angiosperms became one of the megadiverse groups of macroscopic eukaryotes, they forged modern ecosystems and promoted the evolution of extant terrestrial biota. Unequal distribution of species among lineages suggests that diversification, the process that ultimately determines species richness, acted differentially through angiosperm evolution. Magallón et al. investigate how angiosperms became megadiverse by identifying the phylogenetic and temporal placement of exceptional radiations, by combining the most densely fossil-calibrated molecular clock phylogeny with a Bayesian model that identifies diversification shifts among evolutionary lineages and through time. They evaluate the effect of the prior number of expected shifts in the phylogenetic tree....

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A graph

Cell cycle duration in the root apical meristem (RAM) of angiosperms

In plant studies it is essential to determine cell cycle duration (T). Zhukovskaya et al. have previously proposed an exponential model evaluating T in the root apical meristem (RAM) based on the dynamics of root growth, the number of cells in the RAM, and the length of fully elongated cells. Here, a global analysis of the approach was performed. The results show that in most of the 73 angiosperm species examined, the T values obtained by this approach were nearly identical to those obtained by the much more laborious 3H-thymidine method. The ease of the approach promises its wide use.

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Simplified phylogeny of the green plant lineage focusing on the occurrence of WGD (whole-genome duplication) events

Polyploidy and interspecific hybridization shape adaptation, speciation and evolution

About half of all higher plant species are recognizable as evolutionarily recent polyploids, where multiple whole genomes or sets of chromosomes have come together from close ancestors. Additionally, over evolutionary time, all flowering plants have at least one polyploidy event, also known as a whole-genome duplication (WGD), in their ancestry, from before the divergence of gymnosperms and angiosperms, the ζ (zeta) event (see the legend in the paper for the many references). This Annals of Botany Special Issue on Polyploidy in Ecology and Evolution presents the evolutionary consequences of new, recent, and ancient polyploidy. Alix et al. survey experimental, genomic,...

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