Design and maintenance by Peter Hoen
	Updated October 2008

Part 4 (P-R)

In all drawings, the distal pole is on top, the proximal pole at the bottom, unless otherwise specified.
e = equatorial view, p = polar view; H = high level, L = low level.
The terms printed in bold are preferred.
The colors are according the scheme described in the introduction.
Click on a drawing for a full sized picture.

P/E ratio (Erdtman, 1943)
	The ratio of the length of the polar axis (P) to the equatorial diameter (E). Comment: Erdtman suggested a widely used system of shape classes defined on the basis of P/E ratios. See also: oblate, oblate spheroidal, peroblate, perprolate, prolate, prolate spheroidal, shape classes, spheroidal, suboblate, subprolate, subspheroidal.

Palaeopalynology (Manten, 1966)
	The study of fossil palynomorphs. Antonym: actuopalynology.

Palynodebris (Manum, 1976)
	All palynomorph-sized particles in a sediment excluding those that actually are palynomorphs but including, for example, wood fragments, cuticles and some animal remains. See also: phytoclast.

Palynodeme (Visscher, 1971)
	A group of palynomorph species (form-species) that intergrade and represent the reflection of a known or hypothetical plant species. Comment: As originally used the concept was phylogenetic and referred to characters changing in time ("vertical" change). The term is, however, misused by some authors as if synonymous with morphon and the less formal term "complex". See also: morphon.

Palynofacies (Combaz, 1964)
	The assemblage of phytoclasts found in a particular sediment, such as palynomorphs, wood fragments, cuticles, etc. Comment: The term is actually used in two senses, namely the palynolithofacies and palynobiofacies. See also: phytoclast.

Palynogram (Erdtman, 1952)
	A diagram summarising the main morphological features of a palynomorph.

Palynology (Hyde and Williams, 1944)
	The study of pollen grains and spores and of other biological materials that can be studied by means of palynological techniques. Comment: A number of subdisciplines may be recognised, including palaeopalynology, aeropalynology, melissopalynology and pollen analysis.

Palynomorph (Tschudy, 1961)
	A general term for all entities found in palynological preparations. Comment: In addition to pollen grains and spores, the term encompasses acritarchs, dinoflagellates and scolecodonts, but not other microfossils, such as diatoms, that are dissolved by hydrofluoric acid.

Panporate (adj.) (Erdtman and Vishnu-Mittre, 1956)
	Synonym of pantoporate.

Panto-, Pan-
	A prefix for global distribution. Synonym of peri-.

Pantoaperturate (adj.) (Erdtman and Vishnu-Mittre, 1956)
	Describing a pollen grain with apertures spread over the surface sometimes forming a regular pattern. Comment: Such pollen grains may be, for example, pantocolpate, pantocolporate or pantoporate. The terms based on the prefix peri- as used in the classification of pollen types of Iversen and Troels-Smith (1950) are not recommended.

Papilla (pl. papillae, adj. papillate) (Wodehouse, 1935)
	A small protuberance. Comment: The term is mostly used in describing pollen of Taxodiaceae (Gymnospermae).

Papilla (pl. papillae, adj. papillate) (Traverse, 1955)
	A general term, applied in palynology to parallel sided exinous elements with rounded apices, less than 1µm in length. See also: scabrate.

Paracavate (adj.) (Balme, 1988)
	An exine in which the intexine is clearly defined but in which its degree of separation from the exoexine is uncertain or indeterminate. Example: Ancyrospora langii.

Paraisopolar (Praglowski et al., 1983)
	Describing a pollen grain whose polar faces differ only in the attachment of viscin threads to the proximal pole. Synonym of subisopolar. Comment: Most pollen grains with viscin threads have polar faces of which one is less/more convex than the other.

Paraporal lacuna (pl. paraporal lacunae) (Wodehouse, 1935)
	A lacuna of a lophate pollen grain lying in the mesocolpial region adjacent to one side of an equatorial ridge. Example: Taraxacum officinale (Compositae). See also: lacuna.

Paraporal ridge (Wodehouse, 1935)
	A ridge bounding a pore, extending in a meridional direction. Applied to a lophate pollen grain. Examples: Tragopogon pratensis, Taraxacum officinale (Composiatae).

Parasyncolpate (adj.) (Erdtman, 1952) and parasyncolporate (Van der Ham, 1977)
	Describing syncolp(or)ate pollen grains in which the apices of the colpi divide into two branches and anastomose towards the poles, delimiting an isolated area known as the apocolpial field. Examples: Nymphoides peltata (Menyanthaceae), Eugenia (Myrtaceae). See also: syncolp(or)ate, apocolpial field.

Patella (pl. patellae, adj. patellate) (Pocock, 1961a)
	Synonym of patina. See also: capsula, cingulum.

Patina (adj. patinate) (Butterworth and Williams, 1958)
	A thickening of the exine of spores that extends over the entire surface of one hemisphere. Example: Cingulatisporites, Patellasporites.

Pattern
	A general word, applied in palynology either to surface features or infratectal elements, such as columellae.

Pedium (Erdtman, 1966b)
	Synonym of foot layer.

Per-
	A prefix for 1. extremely, and 2. through. Comment: In palynological terms the prefix is often used for complete (e.g. in pertectate) or very (e.g. in peroblate).

Pererect (adj.) (Reitsma, 1970)
	Synonym of perprolate.

Perforate (adj.) (Iversen and Troels-Smith, 1950)
	A general adjective indicating the presence of holes, applied in palynology to holes less than 1µm in diameter and generally situated in the tectum. See also: punctum, scrobiculus.

Peri-
	Synonym of panto-. Comment: Iversen and Troels-Smith (1950) used the term peri- (as for example, in pericolpate, periporate and pericolporate) in their classification of pollen types, but terms based on panto- are much more widely used. See also: pantoaperturate.

Perine (Erdtman, 1943)
	A sporoderm layer that is not always acetolysis resistant and is situated around the exine of many spores. Example: Pteridium (Hypolepidaceae). Synonym of perispore. Comment: The term perine should be used in conjunction with sexine and nexine, whereas perispore should be used with exospore and endospore.

Perinium (Jackson, 1928).
	Synonym of perine. Comment: A latinised form of the term perine.

Perispore (Russow, 1872)
	Synonym of perine. See also: endospore, exospore.

Perisporium (Erdtman, 1943)
	Synonym of perine. Comment: A latinised form of the term perispore.

Peritreme (adj.) (Erdtman and Straka, 1961)
	Describing a pollen grain with equatorial apertures situated around an outline that is circular in polar view. Comment: The term is not recommended because it is based upon the suffix -treme.

Peroblate (adj.) (Erdtman, 1943)
	Describing the shape of a pollen grain or spore in which the ratio between the polar axis and the equatorial diameter is less than 0.50. See also: oblate, oblate spheroidal, P/E ratio, perprolate, prolate, prolate spheroidal, shape classes, spheroidal, suboblate, subprolate, subspheroidal.

Perprolate (adj.) (Erdtman, 1943)
	Describing the shape of a pollen grain or spore in which the ratio between the polar axis and the equatorial diameter is more than 2. See also: oblate, oblate spheroidal, P/E ratio, peroblate, prolate, prolate spheroidal, shape classes, spheroidal, suboblate, subprolate, subspheroidal.

Per-reticulate (adj.) (Fægri and Iversen, 1975)
	Structural elements fused distally forming an open reticulum. Comment: It applies to the same structure as eureticulate, but is defined on a different basis.

Pertectate (adj.) (Erdtman, 1969)
	Synonym of eutectate.

Pertransverse (adj.) (Reitsma, 1970)
	Synonym of perprolate.

Phytoclast (pl.phytoclasts)
	A general term for plant-derived, more or less resistant-walled, particle occurring in a sediment. See also: palynodebris.

Pilum (pl. pila, adj. pilate) (Erdtman, 1952)
	A sexine element, usually standing directly on the nexine, consisting of a rod-like part (columella) and a swollen apical part (caput).

Pitted (adj.)
	A general term for small depressions (Jackson, 1928) Synonym of foveolate (in palynology).

Planaperturate (adj.) (Erdtman, 1952)
	Describing a pollen grain with an angular outline, in which the apertures are situated in the middle of the sides when seen in polar view, rather than at the angles. Example: Tilia (Tiliaceae). Antonym: angulaperturate. Comment: The term is useful for describing the position of apertures, but should be avoided as a description of equatorial outline.

Platea (pl. plateae) (Thomson and Pflug, 1953)
	Areas of the inner wall layer separated by a triradiate channel extending between the endogerminals of a Normapolles pollen grain. Example: Pompeckjoidaepollenites.

Platea luminosa (pl. plateae luminosae) (Iversen and Troels-Smith, 1950)
	Synonym of groove. Comment: The term was introduced for use in striate pollen and to contrast with lumina, which was restricted to reticulate pollen.

Pleurotreme (adj.) (Erdtman and Straka, 1961)
	Synonym of planaperturate.

Plica (pl. plicae, adj. plicate) (Thomson and Pflug, 1953)
	A general term for a fold, applied in palynology to ridge-like folds of the exine in Ephedra (Ephedraceae) and Lusatipollis. See also: polyplicate, taenia.

Pluricolumellate ((adj.) (Reitsma, 1970)
	With the columellae arranged in several rows beneath each murus. See also: duplicolumellate, simplicolumellate.

Polar area (Iversen and Troels-Smith, 1950)
	Synonym of apocolpium. Comment: In spores often used for the area around a pole.

Polar area index (PAI) (pl. polar area indices) (Iversen and Troels-Smith, 1950)
	Synonym of apocolpium index.

Polar axis (pl. polar axes) (Wodehouse, 1935)
	The straight line between the distal and proximal poles of a pollen grain or spore. See also: equatorial diameter, polarity.

Polar distance (Punt, 1984)
	The vertical distance from the equator to the pole (pd).

Polar field (Beug, 1961)
	Synonym of apocolpium.

Polar lacuna (pl. polar lacunae) (Wodehouse, 1928)
	A lacuna situated at the pole of a lophate pollen grain. See also: lacuna, lophate.

Polar view (Erdtman, 1943)
	A view of a pollen grain or spore in which the polar axis is directed towards the observer. Antonym: equatorial view. See also: amb.

Polarity
	The condition of having distinct poles (Jackson, 1928). Comment: The polarity of palynomorphs may be determined from their orientation in tetrads, or by inference from the distribution of apertures, or other features. See also: apolar, heteropolar, isopolar.

Pole (Wodehouse, 1935)
	Either of the two extremities of the polar axis. See also: polar axis.

Pollen (Linnaeus, 1751)
	The microgametophyte of seed plants, developed from the microspore. See also: spore, microspore.

Pollen analysis (Von Post, 1916)
	The study of assemblages of dispersed palynomorphs such as those isolated from samples of peat. See also: palynology.

Pollen cement (Heslop-Harrison, 1968)
	Synonym of pollenkitt.

Pollen class (pl. pollen classes) (Fægri and Iversen, 1950)
	An artificial grouping of pollen grains that share a distinctive character, or suite of characters. Such classes are useful in identification keys and may be subdivided into more restrictive categories, pollen types and pollen groups. Example: tricolpate class.

Pollen coat (Knox, 1984)
	Synonym of pollenkitt.

Pollen group (Punt, 1971)
	A pollen morphological category, subsidiary to a pollen type, including a number of pollen grains that show intergrading characters but no distinguishing characters. See also: pollen class, pollen type.

Pollenkitt (Knoll, 1930)
	A sticky material, produced by the tapetum, that may hold pollen grains together during dispersal. See also: tryphine.

Pollen mother cell
	Synonym of microsporocyte.

Pollen type (Punt, 1971)
	A pollen morphological category, subsidiary to a pollen class, and including pollen grains which can be distinguished either by one distinct character or by a unique combination of characters. See also: pollen class, pollen group.

Pollinium (pl. pollinia)
	A general term for aggregations of many pollen grains, which form dispersal units (Jackson, 1928). Examples: Asclepiadaceae, Orchidaceae. See also: dispersal unit, massula.

Polumbra (Balme, 1988)
	A darkened triangular or subcircular area centred on the proximal pole. Example: Retusotriletes distinctus. Comment: The feature appears to be most commonly observed in specimens that have lost a perisporal outer exoexinal layer. See also: hilum.

Polyad (Iversen and Troels-Smith, 1950)
	A dispersal unit comprising more than four pollen grains. Example: Acacia (Mimosaceae).

Polyannulus (pl. polyannuli, adj. polyannulate) (Batten and Christopher, 1981)
	A structure in which the sexine of the outer aperture has multiple layers each with its own thickening. Example: Atlantopollis. Comment: This term refers especially to pollen grains of the fossil Normapolles group.

Polychotomosulcate (adj.) (Walker and Walker, 1986)
	Describing a pollen grain with a many branched sulcus.

Polyplicate (adj.) (Iversen and Troels-Smith, 1950)
	Describing a pollen grain with more than three meridional ridges (plicae) separated by deep grooves. Example: Ephedra (Ephedraceae). See also: plica, striate, taenia.

Polyporate (adj.) (Moar, 1993)
	With many pores. Synonym of pantoporate and zonoporate.

Pontoperculum (pl. pontopercula, adj. pontoperculate) (Erdtman, 1952)
	A type of operculum that is not completely isolated from the remainder of the sexine but linked to it at the ends of the aperture. Example: Sanguisorba officinalis (Rosaceae), Passieflora tetandra (Passiefloraceae). See also: geminicolpate.

Poral lacuna (pl. poral lacunae) (Wodehouse, 1928)
	A lacuna of a lophate pollen grain surrounding an endoaperture, which communicates with adjacent abporal lacunae via interlacunar gaps. Example: Cichorium intybus (Compositae). See also: lacuna, lophate.

Pore (pl. pores, adj. porate) (Jackson, 1928; Wodehouse, 1935).
	A general term, applied in palynology to a circular or elliptic aperture with a length/breadth ratio less than 2 See also: aperture, porus, ulcus.

Pore canal (Thomson and Pflug, 1953)
	The space between the ectopore and the endopore. See also: aspis channel.

Pore membrane (Wodehouse, 1935)
	The aperture membrane of a pore.

Poro-colpate (adj.) (Clarke et al., 1979)
	Describing a pollen grain with an arrangement of apertures in which colpi alternate with pores round the equator. Example: Pardoglossum (Boraginaceae).

Pororate (adj.) (Erdtman, 1952)
	Describing a pollen grain with compound apertures in which both the ectoaperture and the endoaperture are pores and the two are not congruent. Example: Myrica gale (Myricaceae). Comment: Pollen grains that have congruent ectopores and endopores are generally simply referred to as porate. See also: colporate.

Porus (pl. pori, adj. porate) (Potonié, 1934)
	Synonym of pore.

Pre-
	A prefix for before. Comment: As for example in prepollen, pretectum.

Prepollen (Renault, 1896; Chaloner, 1970)
	The microspores of certain extinct seed plants characterised by proximal apertures and presumed proximal germination, rather than the distal, equatorial or other typical apertures of seed plant pollen grains.

Primexine (Heslop--Harrison, 1963)
	A developmental precursor of at least part of the exine (the sexine/ectexine), formed during the tetrad stage that is composed largely of polysaccharides and therefore lacks resistance to acetolysis.

Pro- (Heslop-Harrison, 1963 )
	A prefix indicating a developmental precursor of a feature. Example: probaculum.

Projectate (adj.) (Mtchedlishvilli, 1961)
	Describing a pollen grain in which the apertures are borne on the ends of strongly projecting arms. Example: Aquilapollenites. See also: triprojectate.

Prolate (Erdtman, 1943)
	Describing the shape of a pollen grain or spore in which the polar axis is larger than the equatorial diameter. Comment: This term belongs to the system of shape classes suggested by Erdtman (1943, and extended in 1952), based on the measurements of the polar axis (P) and equatorial diameter (E). In this system prolate is defined as a ratio between the polar axis and the equatorial diameter of 1.33-2.00. See also: oblate, oblate spheroidal, P/E ratio, peroblate, perprolate, prolate spheroidal, shape classes, spheroidal, suboblate, subprolate, subspheroidal.

Prolate spheroidal (Erdtman, 1952)
	Describing the shape of a pollen grain or spore in which the ratio between the polar axis and the equatorial diameter is 1.00-1.14. See also: oblate, oblate spheroidal, P/E ratio, peroblate, perprolate, prolate, shape classes, spheroidal, suboblate, subprolate, subspheroidal.

Protosaccus (pl. protosacci, adj. protosaccate) (Scheuring, 1974)
	A saccus which is completely filled with an alveolar structure. This feature is used in the description of pollen in the Perm - Trias. Example: Luekisporites virkkiae. Comment: For extant saccate pollen grains don't show this character it is considered to be primitive. See also: bisaccate, monosaccate, pseudosaccus, saccus.

Proximal
	A common descriptive term (Jackson, 1928) used in contrast to distal, applied in palynology to features on the surface that faces towards the centre of the tetrad during development (Wodehouse, 1935). Antonym: distal. See also: ana-, cata-, polarity.

Proximal face (Erdtman, 1952)
	That part of a palynomorph which faces towards the centre of the tetrad, between equator and proximal pole. Antonym: distal face.

Proximal pole (Wodehouse, 1935)
	The centre of the proximal face. Antonym: distal pole. See also: proximal.

Proximocavate (adj.) (Balme, 1988)
	An exine in which the exoexine is detached, or partly detached, from the intexine only on the proximal face.

Pseudoaperture (adj. pseudoaperturate) (Thanikaimoni, 1980)
	A thinning of the exine which, although superficially resembling an aperture, is not associated with a thickening of the intine and is presumed not to function as an exitus. See also: pseudocolpus, pseudopore.

Pseudocolpus (pl. pseudocolpi, adj pseudocolpate) (Iversen and Troels-Smith, 1950)
	A colpus-like pseudoaperture. Example: Myosotis (Boraginaceae). See also: heterocolpate.

Pseudopore (pl. pseudopores, adj. pseudoporate) (Iversen and Troels-Smith, 1950)
	A pore-like pseudoaperture. Comment: The term has also been used for the leptoma of certain coniferous pollen.

Pseudosaccus (pl.pseudosacci, adj. pseudosaccate) (Grebe, 1971)
	An extensive, saccus-like separation in the wall of a spore resembling a saccus, but lacking the characteristic alveolate infrastructure. Example: Grandispora spinosa. See also: camera, saccus.

Psilate (adj.) (Wodehouse, 1928)
	Describing a pollen or spore with a smooth surface.

Psilolophate (adj.) (Wodehouse, 1935)
	Describing a lophate pollen grain which lacks spines. See also: echinolophate, lophate.

Ptychotreme (adj.) (Erdtman and Straka, 1961)
	With apertures situated in invaginations of the outline, when seen in polar view. Comment: The term is not recommended because it is based upon the suffix -treme.

Punctum (pl. puncta, adj. punctate) (Erdtman, 1952)
	A rounded or elongate tectal perforation, less than 1µm in length or diameter. See also: foveola, scrobiculus, tectum perforatum.

Quasisaccus (pl. quasisacci, adj. quasisaccate) (Meyen, 1988)
	Synonym of protosaccus.

Quasitectate (adj.) (Balme, 1988)
	A spore exine in which the outer and inner, more or less homogeneous, layers aer seperated by a clearly defined mesexinous layer of discontinous columellate elements, simulating those that characterise many angiosperm pollen.

Radial
	A general term describing features radiating from a centre. Applied in palynology to the region of a spore beyond the ends of the laesurae.

Radially symmetric (adj.) (Nilsson and Muller, 1978)
	Describing a pollen grain or spore with two or more vertical planes of symmetry, but, if only two such planes are present, then their axes are of equal length.

Radius
	A general term, used in palynology for a laesura in trilete spores.

Rectimurate (adj.) (Erdtman, 1952)
	Describing a pollen grain or spore with more or less straight muri.

Reticuloid (adj.) (Moar, 1993)
	With bacula arranged in a more or less reticulate pattern. Synonym of retipilate.

Reticulum (pl. reticula, adj. reticulate) (Praglowski and Punt, 1973)
	A network-like pattern consisting of lumina or other spaces wider than 1µm bordered by elements narrower than the lumina. See also: microreticum.

Retipilate (adj.) (Erdtman, 1952).
	Describing a reticulum formed by rows of pila instead of muri. Example: Callitriche (Callitrichaceae).

Retusoid (adj.) (Traverse, 1988)
	Describing a spore with prominent contact areas and curvaturae. Example: Retusotriletes.

Rhomboidal tetrad (Erdtman, 1945b)
	A uniplanar tetrad in which the proximal faces of two individual members are in direct contact and the remaining two are separated, giving a rhomboidal outline to the tetrad. Example: Epipactis palustris (Orchidaceae).

Rimula (pl. rimulae, adj. rimulate) (Pflug, 1953)
	The sub-equatorial aperture that encircles pollen grains of the Classopolles group. Example: Corollina (Classopollis). Comment: Potonié (1934) used rimula to refer to short colpi, but the term is no longer used in this sense.

Ruga (pl. rugae, adj. rugate) (Potonié, 1934, emend. Erdtman, 1945a)
	Synonym of colpus.

Rugulate (adj.) (Iversen and Troels-Smith, 1950)
	Describing a type of ornamentation consisting of elongated sexine elements more than 1µm long, arranged in an irregular pattern that is intermediate between striate and reticulate. Examples: Sedum (Crassulaceae), Ulmus (Ulmaceae), Camptotriletes corrugatus.

Rupate (adj.) (sing. rupus, pl. rupi) (Erdtman, 1952)
	Synonym of loxoaperturate.