Pollen Key for Selected Plants of the San Francisco Estuary Region (DRAFT)
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.
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
top
mid
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.
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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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mid
Corylus california
Hazel
Family: Betulaceae
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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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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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Dryopteris
Wood Fern
Family: Polypodiaceae
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Pinus contorta
Lodgepole Pine
Family: Pinaceae
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Alnus rugosa
Alder
Family: Corylaceae
Notes: Pores arrainged on equator. Compare with Juglans.
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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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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.
top
mid
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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Potamogeton gramineus
Pondweed
Family: Zosteraceae
Notes: Compare with Triglochin.
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tetrad
tetrad
Typha augustifolia
Cattail
Family: Typhaceae
Notes: Often in tetrads. Pore often present as circular gap in exine.
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