Pollen Key for Selected Plants of the San Francisco Estuary Region (DRAFT)

Organized by pollen grain type

Tricolporate
Triporate
Tricolpate
Monoporate
Monocolpate
Vesiculate
Stephanoporate
Trilete spore type
Periporate
Inaperturate
Tetrad

Clicking on any image will display a double-size image.
"Top", "mid", and "bottom" refer to the location of the plane of focus relative to the pollen grain.


Tricolporate type


Aesculus california
California Buckeye
Family: Hippocastanaceae

low mid
Artemisia california
Sage
Family: Compositae
Notes: Pores sometimes missing. Fine spines often visible.

low
Ceanothus foliosis
Family: Rhamnaceae


Cressa truxillensis
Alkali Weed
Family: Convolvulaceae

mid
Eriogonum crocatum
Umbrella Plant
Family: Polygonaceae

Etop Emid
Eriogonum hooveri
Umbrella Plant
Family: Polygonaceae


Eucaliptus globulus
Family: Myrtaceae (Myrtle family)
Notes: Triangular pattern in center of grain is important distinguishing feature. Compare with Rhamnaceae, which has no triangle pattern and is less rounded in outline.

top mid bottom pole view
Rumex
Sorrel
Family: Polygonaceae


Salix lasiolepis
Willow
Family: Salicaceae
Notes: Salix may or may not have pores. Exine appears as a coarse "net."


Lithocarpus densiflora
Tan Oak
Family: Fagaceae

top mid
Cirsium californicum
High-spine Compositae
Family: Compositae
Notes: If low-spined, check Ambrosia. If intricately structured, check Liguliflorae.


Conium maculatum
Poison Hemlock
Family: Umbelliferae
Notes: Peanut-like shape (similar to most Umbelliferae; restriction at the equator is not present in all Umbelliferae.)

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Triporate type

mid
Corylus california
Hazel
Family: Betulaceae

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Tricolpate type


Cerocarpus ledifolius
Mountain Mahogony
Family: Rosaceae

top mid
Quercus agrifolia
Oak
Family: Fagaceae
Notes: Coarse, rough exine is characteristic. Edges of colpi often have torn, irregular apparance.

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Monoporate type

mid damaged
Distichlis spicata
Salt Grass
Family: Poaceae
Notes: Can have fine "sandy" patterning on exine.


Sequoia sempervirens
Redwood
Family: Taxodiaceae
Notes: Small papilla with pore at end, often not visible. As with other TCTs, often split into "pac-man" shape. Split often through papilla, obscuring it.

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Monocolpate/Monolete type


Dryopteris
Wood Fern
Family: Polypodiaceae

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Vesiculate type


Pinus contorta
Lodgepole Pine
Family: Pinaceae

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Stephanoporate type


Alnus rugosa
Alder
Family: Corylaceae
Notes: Pores arrainged on equator. Compare with Juglans.

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Trilete spore type


Botrychium simplex
Grape-Fern
Family: Ophioglossaceae

mid top showing trilete scar
Lycopodium spp.
Family: Lycopodiaceae
Notes: Trilete spore. May appear lit from inside. Used as a control in the Berkeley lab.


Pteridium aquilinum
Fern
Family: Polypodiaceae

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Periporate type

top top mid top mid
Atriplex patula
Family: Chenopodiaceae

top
Juglans california
California Walnut
Family: Juglandaceae
Notes: Pores always protruding. One hemisphere free of pores (heteropolar). Compare with Alnus, Plantago, or Sarcobatus.

Salicorniatop Salicorniamid
Salicornia virginica
Pickleweed
Family: Chenopodiaceae

damaged
Scirpus robustus
Tule
Family: Cyperaceae
Notes: Rough exine texture is an important distinguishing feature. Pores indistinct.

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Inaperturate type


Potamogeton gramineus
Pondweed
Family: Zosteraceae
Notes: Compare with Triglochin.

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Tetrad type

tetrad tetrad
Typha augustifolia
Cattail
Family: Typhaceae
Notes: Often in tetrads. Pore often present as circular gap in exine.


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