Pollen under the Microscope

Pollen

Pollens are propagules from vascular plants and spores are the propagules from the nonvascular plants. Spores have a shell (exine) consisting of one layer, though a loose outer sack, the perine, may be present (see fern spores for an example). Pollens have an exine typically of two or more layers. Spores are not optically active, that is when they are viewed between crossed polarizing filters they disappear. Pollens are often optically active or contain starch grains that are optically active. These pollens are visible when viewed between crossed polarizing filters. As pollen grains age they loose the optical activity and the starch grains dissipate into the environment. These starch grains carry the allergen for that pollen with them. Most standard guides to pollen identification are based on "acetolyzed" grains, chemicaly processed pollen that removes the contents of the grain and most of the optical activity of the grain. It also swells the grain. This is a necessary practice in the analysis of fossil grains but for environmental analysis the fresh pollen grain is more characteristic. Most of the pollen grains shown here are fresh. They are from honeybee frass (fecal pellet), regional honey samples, or from recent environmental samples. An abridged morphological key is provided here (see References at end). - Click here to link to a good website containing a glossary of morphlogical terms used to describe pollens and spores.

Click here to link to another good website for pollen images by species and by size.

Vesiculate Pollens

Vesiculate Pollens: Pollens with air sacks to increase bouyancy. The sacks are typically two per grain at the bottom of the grain, but may also be doughnut shaped under the grain.

Vesiculate pollens are found in the Abies (Fir), Picea (Spruce), Pinus (Pine), Podocarpus (Podocarpus), and Tsuga (Hemlock).

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Trilete or Trichotomocolpate

Trilete or Trichotomocolpate: Pollens with three furrows joined at one pole.

Trilete (Trichotomocolpate) pollens are found in the Cocos (Coconut), Sphagnum (Peat Moss), Pteridophyta (Fern), and Lycopodium (Clubmoss).

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Inaperturate

Inaperturate Pollens: Pollens without air sacks that don't have any visible openings in the exine.

Inaperturate pollens are found in the Cupressaceae (Cedar), Equisetum (Horsetails), Larix (Tamarack), Pseudotsuga (Douglas Fir)), and Salicaceae (Cottonwood and Aspen).

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Polyplicate

Polyplicate: Pollens with numberous sharp meridional ridges.

Monolete

Monolete: Kidney-shaped fern spores with one furrow and without an associated pore or transverse furrow.

Licorice Fern Spores Under the Microscope

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Monocolpate

Monocolpate: Pollens with one furrow and without an associated pore or transverse furrow.

Monocolpate pollens are found in the Liliaceae (Lily Family) primarily.

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Dicolpate: Pollens with two furrows and without associated pores or transverse furrows.

Tricolpate

Tricolpate: Pollens with three furrows and without associated pores or transverse furrows.

Polycolpate: Pollens with more than three furrows and without associated pores or transverse furrows.

Stephanocolpate

Stephanocolpate: Pollens as above and all the furrows are oriented meridionally

Pericolpate: Pollens as above but all the furrows are not oriented meridionally

Heterocolpate

Heterocolpate: Pollens with multiple furrows, some with pores.

Canadian Honey Pollen Under the Microscope

Syncolpate

Syncolpate: Pollens with fused furrows.

Syncolpate pollens are found in the Primulaceae (Primrose Family), Eucalyptus (Eucalyptus), and Berberidaceae (Barberry and oregon Grape).

Primrose (Primula stricta or scotica) Pollen

Oregon Grape (Mahonia [Berberis] aquifolium) Pollen

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Monoporate

Monoporate: Pollens with one pore and without an associated furrow.

Monoporate pollens are found in the Gramineae (Grasses) primarily but also in the Taxodiaceae (Redwood and Cypress).

Diporate: Pollens with two pores and without associated furrows.

Triporate

Triporate: Pollens with three pores and without associated furrows.

Triporate pollens are very common so they will be sub-divided by surface ornimentation or other Dominant feature. Some species than normally have triporate pollens may show four pores.

Triporate, Echinate pollens

Triporate, psilate (smooth) pollens

Triporate, with Vetibulum (Pore Cavity) pollens

Triporate, baculate and clavate, them forming a reticulum pollens

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Stephanoporate

Stephanoporate: Pollens with more than three pores and all pores are located equatorially.

Stephanoporate pollens are found in the Campanulaceae (Colorado Bluebells), Corylaceae (Alder),Onagraceae, and in Ulmaceae (Elm).

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Periporate

Periporate: Pollens as above but the pores are not located just equatorially.

Periporate pollens are very common so they will be sub-divided by surface ornimentation or other Dominant feature.

Periporate, psilate (smooth) pollens are found in the Boraginaceae (Lithodora), in the ().

Periporate, scabrate (scab-like) pollens are found in the Plantaginaceae (Plantain) in the ().

Narrow Leaf Plantain (Plantago lanceloata) Pollen

Periporate, echinate pollens are found in the Polygonaceae () in the ().

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Tricolporate or Trizonocolporate

Tricolporate: Pollen three furrows, each with a pore.

ECHINATE (Spikes) Trizonocolporate

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RETICULATE (Cavities) Trizonocolporate

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SCABRATE (No distinct surface structure) Trizonocolporate

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Striate (Roughly Parallel Elongation) Trizonocolporate

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Polycolporate: Pollen with more than three furrow, each with a pore.

Stephanocolporate

Stephanocolporate: Pollens as above and all the furrows are oriented meridionally

Pericolporate: Pollens as above but all the furrows are not oriented meridionally

Echinolophate (Fenestrate)

Echinolophate (Fenestrate): Pollen with geometrically positioned large openings in the "tectum", some with pores.

Fenestrate pollens are found in the Lactuceae (Dandelion) primarily.

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Polyad

Polyad: Pollen consisting of more than one grain.

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Pollens with Polarized Light

Other Pollens

References

Faegri, Knut and Johs Iversen, TEXTBOOK OF POLLEN ANALYSIS, Hafner Publishing Company, 1964.

Kapp, Ronald O., HOW TO KNOW POLLEN AND SPORES, Wm. C. Brown Company, 1969.

Moore, P.D., J. A. Webb, and M. E. Collinson, POLLEN ANALYSIS, Blackwell Scientific Publications, 1991

Smith, E. Grant, SAMPLING AND IDENTIFYING ALLERGENIC POLLENS AND MOLDS, Blewstone Press, San Antonio, Texas, 1990