Appendix 1. Glossary of palynological terms (modified from Punt et al, 1994; Traverse, 1988; Faegri and Iversen, 1975; Kremp, 1965).

Amb: Outline of a pollen grain or spore as viewed from directly above one of the poles (i.e., round amb, triangular amb).

Annulus: A ring bordering a pore of a pollen grain, in which the ektexine is modified (usually thickened) (Plate 23: 380).

Aperture: Modification of the exine of a pollen grain or spore that is the site of exit for the contents (e.g., laesura, colpus, pore).

Apocolpial field: A region at the pole of a parasyncolporate pollen grain, delimited by the margins of the anastomosing colpi (Plate 23: 390).

Areolae: Feature of ornamentation in which the sexine is composed of circular or polygonal areas.

Aspidate: Bearing the apertures on dome-like protrusions (e.g., Ludwigia, Morella) (Plate 23: 381, 382). Grains with an aspidate external form often are vestibulate internally.

Baculate: Sculpture of pollen and spores consisting of bacula, which are tiny rods (lacking thickenings or thinnings at either end). These vary widely in size and distribution (either clustered or isolated).

Cavate: Feature where a cavity (cavea) formed between two layers of the exine and extends to the colpus margin where the layers meet (e.g., Ambrosia).

Clavate: Sculpture of pollen and spores consisting of clavae, which are rods with enlarged, club-like ends.

Colporate: Pollen grain having both colpi and pores (or some other thinning of the exine) oriented along the equator.

Colporoidate: Pollen grain having colpi but a weakly developed pore.

Columella: Rod-like element of the sexine supporting a tectum. Pl. colummellae.

Colpus: Longitudinal furrow-like modification in the exine of pollen grains, associated with germination and often also important for harmomegathic swelling and shrinking. When used strictly, the colpus must be meridional and will cross the equatorÑthus restricting its use to dicotyledonous angiosperms. More loosely, the term is synonymous with sulcus. Pl. colpi.

Distal: The part of a spore or pollen grain that faces outward from the center of a tetrad.

Echinate: Sculpture of pollen and spores consisting of echinae (spines).

Equator: Imaginary line connecting points midway between poles of a spore or pollen grain.

Exine: The outer, very resistant layer of the two major layers forming the wall of spores and pollen, consisting principally of sporopollenin.

Gemmate: Sculpture of pollen and spores consisting of more or less spherical projections.

Harmomegathus: The membrane of a pollen grain aperture when it serves to accommodate, by expansion and contraction, changes in volume of the grain, which usually result from taking up or loss of water.

Heterobrochate: A term used for reticulate sculpture in which the lumina (and their enclosing muri) are of varying size across the palynomorph surface, typically in proximity to apertures (c.f., Salix).

Homobrochate: A term used for reticulate sculpture in which the lumina (and their enclosing muri) are of approximately uniform size across the palynomorph surface.

Heterocolporate: Pollen grains having pores in some colpi and not in others; with both simple and compound apertures.

Lacuna: In lophate grains, a depressed area surrounded by ridges (Plate 23: 384). Pl. lacunae.

Laesura: The scar on the proximal face of an embryophytic spore that marks the original contact with other members of the tetrad. It may be monolete, trilete, or rarely dilete. Pl. laesurae.

Lalongate: Term describing pore that is expanded along the equatorial axis of a pollen grain (typically tricolporate) (Plate 23, Figures 385, 386).

Lobate: An equatorially aperturate pollen grain with a lobed shape in polar view (e.g., Conocarpus).

Lophate: Pollen grains in which outer exine is raised in a pattern of ridges and surrounded by lacunae (Plate 23: 384).

Lumina: The depressions between muri of reticulate sculpture (Plate 23: 387).

Margo: An area of exine adjacent to the colpus that is differentiated from the remainder of the sexine either in ornamentation or in thickness.

Muri: The more or less vertical walls which form positive reticulate sculpture in pollen and spores (Plate 23: 387).

Nexine: The inner, non-sculptured part of the exine (Plate 23: 382, 383).

Oblate: The shape of a spore or pollen grain when the polar axis is shorter than the equatorial diameter.

Operculum: A thicker central part of a pore membrane of a pollen grain (Plate 23: 380).

Os: The inner aperture of a complex pore structure (Plate 23: 381, 382). Pl. Ora.

Parasyncolporate: Describing syncolporate pollen grains in which the apices of the colpi divide into two branches and anastomose toward the poles, delimiting an isolated area known as the apocolpial field (Plate 23: 390).

P/E ratio: The ratio of the length of the polar axis (P) to the equatorial diameter (E).

Papilla: A small protuberance.

Periporate: Pollen grains with many pores scattered over the surface.

Perisporium: An additional wall layer external to the exine in certain spores and pollen. It is composed of thin and loosely attached sporopollenin and is therefore not usually encountered in dispersed fossil palynomorphs. Syn. perispore, perine (Plate 23: 388).

Pitted: Sculpture of pollen and spores consisting of small depressions (pits) Syn. Foveolate.

Polar Area: The part of a pollen grain poleward from the ends of the colpi and their associated structures (Plate 23: 389).

Polar Area Index (PAI): The ratio between the diameter of the polar area of a pollen grain and the diameter of the grain.

Pole: The center of both the distal and proximal surfaces.

Pollen: The microgametophyte of seed plants, enclosed in the microspore wall. In fossil pollen, only the microspore wall, or exine, remains after lithification removes the microgametophyte and intine. Similarly, the exine is all that remains after acetolysis of modern pollen.

Pore: More or less circular to slightly oval thinnings or openings in the exine of pollen grains. Pores may occur alone or in assocation with colpi.

Prolate: The shape of a spore or pollen grain in which the polar axis is longer than the equatorial diameter.

Proximal: The part of a spore or pollen grains that faces towards the center of a tetrad.

Pseudocolpus: A colpus-like modification of the exine of pollen grains, differing from a true colpus in that it is never a site of pollen tube emergence.

Psilate: Sculpture type, in which the relatively smooth walls of pollen and spores lack prominent sculpture. The term also applies to exines with pits or reticula less than 1 µm in diameter.

Reticulate: A term for sculpture of pollen and spores consisting of a more or less regular network of ridges (muri). Such sculpture is a positive reticulum.

Rugulate: Sculpture type of pollen and spores consisting of wrinkle-like ridges that irregularly anastomose.

Scabrate: A term for sculpture of pollen and spores, consisting of more or less isodiametric projections (scabrae), less than 1 µm in diameter.

Sculpture: The surface relief, or topography, of a spore or pollen grain. Syn. Ornamentation.

Sexine: The outer, sculptured layer of the exine, which lies above the nexine (Plate 23: 382, 383).

Sporopollenin: The very resistant and refractory organic substance of which the exine and perine of pollen and spores are composed. Sporopollenin gives the palynomorph its extreme durability, being readily destroyed only by oxidation or prolonged high temperature. It is a probably a high-molecular-weight polymer of carotenoids.

Stephanocolporate: Pollen grains having more than three colpi, equatorially arranged and provided with pores.

Stephanoporate: Pollen grains having more than three pores, disposed on the equator.

Striate: A term for pollen sculpture characterized by multiple, more or less parallel grooves and ribs in the exine.

Subspheriodal: The shape of a spore or pollen grain in which the P/E ratio is 0.75–1.33.

Spheroidal: The shape of a spore or pollen grain in which the polar axis and equatorial diameter are approximately equal.

Sulcus: An elongate aperture in the exine of pollen grains. The term is usually restricted to a distal furrow of pollen grains with only one such aperture, when this furrow has the distal pole in its center.

Syncolpate: Of pollen grains in which the colpi join, normally near the pole (Plate 23: 390).

Tectate: A pollen grain whose sexine is supported by columellae, granules, or other elements.

Ulcus: A thin place in the exine, more or less pore-like, but irregular in outline, and often broken up into patches as in some Cyperaceae (Plate 23: 391). Pl. Ulci.

Vestibulum: In porate grains, the space between the external opening in the ektexine and the internal opening in the endexine of a pollen grain with a complex porate structure (Plate 23: 381, 382).