absolute pollen frequency
(APF)The expression of pollen data from sediments in terms of the absolute numbers (for each species, genus, or family) per unit area of surface and, where deposition rates are known, per unit time. ...
aeropalynology
The study of pollen grains and spores in the atmosphere. This is important for allergy studies (e.g. of hay fever), for understanding the spread of diseases in man, other animals, and agricultural ...
Allerød
A north-west European interstadial, from c.12 000 to 10 800 years bp; in Britain not usually distinct from the Bølling. Pollen records point to a cool temperate flora, with birch. See Willard et al. ...
allogamy
Fertilization that involves pollen and ovules from different flowers. See also autogamy, geitonogamy, and xenogamy.
anther
The upper two-lobed part of a plant stamen, usually yellow in colour. Each lobe contains two pollen sacs within which are numerous pollen grains, which are released when the anther ruptures.
antherozoid
The motile male gamete of algae, fungi, bryophytes, clubmosses, horsetails, ferns, and certain gymnosperms. Antherozoids usually develop in an antheridium but in certain gymnosperms, such as Ginkgo ...
aperturate
Applied to a structure having openings (apertures), especially to a pollen grain with regions where only nexine is present or exine is lacking completely.
bee
Traditionally taken as the type of an industrious and productive worker. Bees are also the emblem of St Ambrose (see also beehive) and St John of Chancery.There are a number of superstitions ...
buzz pollination
The shedding of pollen from anthers that project from the flower, due to stimulation that occurs when the rapid vibration of a bee's wings resonates with the natural frequency of the anther ...
callose
An insoluble glucan that is found in higher plants, in which glycosidic (see glycoside) linkages join the first and third carbon atoms of neighbouring beta-glucose units. Structurally it is similar ...
Clavatipollenites
A miospore from the Barremian (Lower Cretaceous); one of the oldest known angiosperm pollen grains. It is oval and monosulcate (see sulcus).
colpus
(pl. colpi)A germinal groove or aperture on the surface of a pollen grain, which is elliptical or approximately rectangular in shape and at least twice as long as it is wide. The shape and ...
connective tissue
The tissue that supports, binds, or separates more specialized tissues and organs or functions as a packing tissue of the body. It consists of an amorphous ground substance of mucopolysaccharides in ...
controlled pollination
A common practice in plant hybridization of bagging the pistillate flowers to protect them from undesired pollen. When the pistillate flowers are in a receptive condition, they are dusted with pollen ...
corpus
1 The body of a pollen grain that has bladders, or air-filled sacs (e.g. Pinus).2 In angiosperms, the cells below the tunica of the apical meristem.
cross-breeding
Usually, outbreeding or the breeding of genetically unrelated individuals. In animals it refers to the mating of individuals that are not consanguineous (see consanguinity).
cross-pollination
The transfer of pollen from the stamen of a flower to the stigma of a flower of a different genotype but usually of the same species, with subsequent growth of the pollen tube. See also ...
Cycadophyta
A phylum of seed plants (see gymnosperm) that contains many extinct species; the few modern representatives of the group include Cycas and Zamia. Cycads inhabit tropical and subtropical regions, ...
