Spermatophyte in the context of "Seed dispersal"

⭐ In the context of seed dispersal, spermatophyte plants are fundamentally limited in their ability to spread their offspring by what primary factor?

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⭐ Core Definition: Spermatophyte

A seed plant or spermatophyte (from Ancient Greek σπέρμα (spérma) 'seed' and φυτόν (phutón) 'plant'; lit.'seed plant'), also called a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae.

The term phanerogam or phanerogamae is derived from Ancient Greek φανερός (phanerós), meaning "visible", in contrast to the term "cryptogam" or "cryptogamae" (from Ancient Greek κρυπτός (kruptós) 'hidden', and γαμέω (gaméō), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae).

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👉 Spermatophyte in the context of Seed dispersal

In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, such as the wind, and living (biotic) vectors such as birds. Seeds can be dispersed away from the parent plant individually or collectively, as well as dispersed in both space and time.

The patterns of seed dispersal are determined in large part by the dispersal mechanism and this has important implications for the demographic and genetic structure of plant populations, as well as migration patterns and species interactions. There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus.

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In this Dossier

Spermatophyte in the context of Conifer

Conifers (/ˈkɒnɪfər/) are a group of seed plants, a subset of gymnosperms. They are mainly evergreen trees with a regular branching pattern, reproducing with male and female cones, usually on the same tree. They are wind-pollinated and the seeds are usually dispersed by the wind. Scientifically, they make up the division Pinophyta, also known as Coniferae. All extant conifers except for the Gnetophytes are perennial woody plants with secondary growth. There are over 600 living species.

Conifers first appear in the fossil record over 300 million years ago in the Carboniferous. They became dominant land plants in the Mesozoic, until flowering plants took over many ecosystems in the Cretaceous. Many conifers today are relict species, surviving in a small part of their former ranges. Such relicts include Wollemia, known only from a small area of Australia, and Metasequoia glyptostroboides, known from Cretaceous fossils and surviving in a small area of China.

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Spermatophyte in the context of Egg

An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell – a zygote. Within the vessel, an embryo is incubated until it has become an animal fetus that can survive on its own, at which point the animal hatches. Reproductive structures similar to the egg in other kingdoms are termed "spores", or in spermatophytes "seeds", or in gametophytes "egg cells".

Most arthropods, vertebrates (excluding live-bearing mammals), and mollusks lay eggs, although some, such as scorpions, do not. Reptile eggs, bird eggs, and monotreme eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Eggs laid on land or in nests are usually kept within a warm and favorable temperature range while the embryo grows. When the embryo is adequately developed it hatches; i.e., breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering.

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Spermatophyte in the context of Pteridospermatophyta

Pteridospermatophyta, also called pteridosperms or seed ferns, are a polyphyletic grouping of extinct seed-producing plants. The earliest fossil evidence for plants of this type are the lyginopterids of late Devonian age. They flourished particularly during the Carboniferous and Permian periods. Pteridosperms declined during the Mesozoic Era and had mostly disappeared by the end of the Cretaceous Period, though Komlopteris seem to have survived into Eocene times, based on fossil finds in Tasmania.

With regard to the enduring utility of this division, many palaeobotanists still use the pteridosperm grouping in an informal sense to refer to the seed plants that are not angiosperms, coniferoids (conifers or cordaites), ginkgophytes (ginkgos or czekanowskiales), cycadophytes (cycads or bennettites), or gnetophytes. This is particularly useful for extinct seed plant groups whose systematic relationships remain speculative, as they can be classified as pteridosperms with no invalid implications being made as to their systematic affinities. Also, from a purely curatorial perspective the term pteridosperms is a useful shorthand for describing the fern-like fronds that were probably produced by seed plants, which are commonly found in many Palaeozoic and Mesozoic fossil floras.

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Spermatophyte in the context of Inflorescence

In botany, an inflorescence is a group or cluster of flowers arranged on a plant's stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a main axis (peduncle) and by the timing of its flowering (determinate and indeterminate).

Morphologically, an inflorescence is the modified part of the shoot of seed plants where flowers are formed on the axis of a plant. The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes.

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