Pollen

exinepollen grainmicrosporogenesispollen grainsmonosulcatepollenscolpiflower pollenechinatepollination
Pollen is a fine to coarse powdery substance comprising pollen grains which are male microgametophytes of seed plants, which produce male gametes (sperm cells).wikipedia
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Stamen

antheranthersstamens
Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants.
The stamen (plural stamina or stamens) is the pollen-producing reproductive organ of a flower.

Sporopollenin

Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants.
It is a major component of the tough outer (exine) walls of plant spores and pollen grains.

Palynology

palynologicalpollen analysispalynologist
The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.
It is the science that studies contemporary and fossil palynomorphs, including pollen, spores, orbicules, dinocysts, acritarchs, chitinozoans and scolecodonts, together with particulate organic matter (POM) and kerogen found in sedimentary rocks and sediments.

Conifer cone

conespine coneseed cones
Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants.
The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity.

Pollen tube

pollen tubespollen-tubepollen tube growth and guidance
If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. When placed on the stigma of a flowering plant, under favorable circumstances, a pollen grain puts forth a pollen tube, which grows down the tissue of the style to the ovary, and makes its way along the placenta, guided by projections or hairs, to the micropyle of an ovule.
The pollen tube acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms.

Flower

flowersfloralflowering
Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower.
Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen.

Flowering plant

Angiospermsflowering plantsangiosperm
Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower.
Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens (or microsporophylls).

Pollination

pollinatedpollinatecross-pollination
The transfer of pollen grains to the female reproductive structure (pistil in angiosperms) is called pollination.
Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind.

Anemophily

wind-pollinatedanemophilouswind pollination
Additionally, gymnosperm pollen grains often have air bladders, or vesicles, called sacci. The sacci are not actually balloons, but are sponge-like, and increase the buoyancy of the pollen grain and help keep it aloft in the wind, as most gymnosperms are anemophilous.
Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind.

Entomophily

entomophilousinsect-pollinatedentomogamy
Entomophilous (literally insect-loving) plants produce pollen that is relatively heavy, sticky and protein-rich, for dispersal by insect pollinators attracted to their flowers.
Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects.

Pollinator

pollinatorspollinatingpollinated
Entomophilous (literally insect-loving) plants produce pollen that is relatively heavy, sticky and protein-rich, for dispersal by insect pollinators attracted to their flowers.
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower.

Paleontology

paleontologistpalaeontologistpalaeontology
The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics.
Palynology, the study of pollen and spores produced by land plants and protists, straddles paleontology and botany, as it deals with both living and fossil organisms.

Podocarpus

podocarpyellowwoodyellowwoods
Modern pine, spruce, and yellowwood trees all produce saccate pollen.
Each triangular microsporophyll has two basal pollen producing pollen sacs.

Eudicots

Core eudicotseudicottricolpate
Eudicots have pollen with three colpi (tricolpate) or with shapes that are evolutionarily derived from tricolpate pollen.
The other name for the eudicots is tricolpates, a name which refers to the grooved structure of the pollen.

Gynoecium

pistilcarpelstyle
Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants. The transfer of pollen grains to the female reproductive structure (pistil in angiosperms) is called pollination. When placed on the stigma of a flowering plant, under favorable circumstances, a pollen grain puts forth a pollen tube, which grows down the tissue of the style to the ovary, and makes its way along the placenta, guided by projections or hairs, to the micropyle of an ovule.
The gynoecium is the innermost whorl of a flower; it consists of (one or more) pistils and is typically surrounded by the pollen-producing reproductive organs, the stamens, collectively called the androecium.

Meiosis

meioticsyzygymeiosis I
In a process called microsporogenesis, four haploid microspores are produced from each diploid sporogenous cell (microsporocyte, pollen mother cell or meiocyte), after meiotic division.
In some cases all four of the meiotic products form gametes such as sperm, spores, or pollen.

Palynivore

pollenPalynivory
Many insects and some mites are specialized to feed on pollen, and are called palynivores.
In zoology, a palynivore /pəˈlɪnəvɔːɹ/, meaning "pollen eater" (from Greek παλύνω palunō, "strew, sprinkle", and Latin, vorare, meaning "to devour") is an herbivorous animal which selectively eats the nutrient-rich pollen produced by angiosperms and gymnosperms.

Pine

Pinuspine treepine trees
Modern pine, spruce, and yellowwood trees all produce saccate pollen. Pollen grains of pines, firs, and spruces are winged.
The male cones are small, typically 1–5 cm long, and only present for a short period (usually in spring, though autumn in a few pines), falling as soon as they have shed their pollen.

Allergic rhinitis

hay feverhayfeverhay-fever
Nasal allergy to pollen is called pollinosis, and allergy specifically to grass pollen is called hay fever.
Those whose symptoms are due to pollen typically develop symptoms during specific times of the year.

Microsporangia

microsporangiummicrosporophylls
Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower.
These become pollen grains, within which the microspores divide twice by mitosis to produce a very simple gametophyte.

Pinophyta

coniferconiferousconifers
Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants.
It was found recently that the pollen of conifers transfers the mitochondrial organelles to the embryo, a sort of meiotic drive that perhaps explains why Pinus and other conifers are so productive, and perhaps also has bearing on (observed?) sex-ratio bias

Sperm

sperm cellspermatiasperm cells
If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte.
In flowering plants, sperm nuclei are produced inside pollen.

Monocotyledon

Monocotsmonocotmonocotyledonous
The predominant form amongst the monocots is successive, but there are important exceptions.
Correlation with morphological criteria showed that the defining feature was not cotyledon number but the separation of angiosperms into two major pollen types, uniaperturate (monosulcate and monosulcate-derived) and triaperturate (tricolpate and tricolpate-derived), with the monocots situated within the uniaperturate groups.

Ovary (botany)

ovaryovariessuperior
When placed on the stigma of a flowering plant, under favorable circumstances, a pollen grain puts forth a pollen tube, which grows down the tissue of the style to the ovary, and makes its way along the placenta, guided by projections or hairs, to the micropyle of an ovule.
Above the ovary is the style and the stigma, which is where the pollen lands and germinates to grow down through the style to the ovary, and, for each individual pollen grain, to fertilize one individual ovule.

Ragweed

AmbrosiaBursageHymenoclea
Most late summer and fall pollen allergies are probably caused by ragweed, a widespread anemophilous plant.
Ragweed pollen is notorious for causing allergic reactions in humans, specifically allergic rhinitis.