Pollen Key for Selected Plants of the San Francisco Estuary Region (DRAFT)
Chenopodiaceae
Cyperaceae
Compositae
Convolvulaceae
Corylaceae
Dennstaedtiaceae
Dryopteridaceae
Fagaceae
Hippocastanaceae
Juglandaceae
Lycopodiaceae
Myrtaceae
Ophioglossaceae
Pinaceae
Poaceae
Polygonaceae
Potamogetonaceae
Rhamnaceae
Rosaceae
Salicaceae
Taxodiaceae
Typhaceae
Umbelliferae
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.
top
mid
Salicornia virginica
Pickleweed
Grain Type: Periporate
top
top
mid
top 
mid
Atriplex patula
Grain Type: Periporate
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Pteridium aquilinum
Fern
Grain Type: Trilete spore
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Dryopteris
Wood Fern
Grain Type: Monocolpate
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Family Cyperaceae (Sedge Family)
damaged
Scirpus robustus
Tule
Grain Type: Periporate
Notes: Rough exine texture is an important distinguishing feature. Pores indistinct.
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Family Typhaceae (Cattail family)
tetrad
tetrad
Typha augustifolia
Cattail
Grain Type: Tetrad
Notes: Often in tetrads. Pore often present as circular gap in exine.
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Family Compositae (Asteraceae) (Sunflower Family)
low
mid
Artemisia california
Sage
Grain Type: Tricolporate
Notes: Pores sometimes missing. Fine spines often visible.
top
mid
Cirsium californicum
High-spine Compositae
Grain Type: Tricolporate
Notes: If low-spined, check Ambrosia. If intricately structured, check Liguliflorae.
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Family Convolvulaceae (Morning Glory Family)
Cressa truxillensis
Alkali Weed
Grain Type: Tricolporate
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Family Fagaceae (Oak Family)
top
mid
Quercus agrifolia
Oak
Grain Type: Tricolpate
Notes: Coarse, rough exine is characteristic. Edges of colpi often have torn, irregular apparance.
Lithocarpus densiflora
Tan Oak
Grain Type: Tricolpate
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Myrtaceae Family (Myrtle Family)
Eucaliptus globulus
Grain Type: Tricolporate (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.
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Family Ophioglossaceae (Adder's Tongue Family)
Botrychium simplex
Grape-Fern
Grain Type: Trilete spore
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Family Pinaceae (Pine family)
Pinus contorta
Lodgepole Pine
Grain Type: Vesiculate
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Family Poaceae (Grass family)
mid
damaged
Distichlis spicata
Salt Grass
Grain Type: Monoporate
Notes: Can have fine "sandy" patterning on exine.
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Potamogeton gramineus
Pondweed
Grain Type: Inaperturate
Notes: Compare with Triglochin.
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Family Rosaceae (Rose family)
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Cerocarpus ledifolius
Mountain Mahogony
Grain Type: Tricolpate
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low
Ceanothus foliosis
Grain Type: Tricolporate
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Family Salicaceae (Willow Family)
Salix lasiolepis
Willow
Grain Type: Tricolporate
Notes: Salix may or may not have pores. Exine appears as a coarse "net."
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Family Taxodiaceae (Bald Cypress Family)
Sequoia sempervirens
Redwood
Grain Type: Monoporate
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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Conium maculatum
Poison Hemlock
Grain Type: Tricolporate
Notes: Peanut-like shape (similar to most Umbelliferae; restriction at the equator is not present in all Umbelliferae.)
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Aesculus california
California Buckeye
Grain Type: Tricolporate
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top
Juglans california
California Walnut
Grain Type: Periporate
Notes: Pores always protruding. One hemisphere free of pores (heteropolar). Compare with Alnus, Plantago, or Sarcobatus.
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top
mid
bottom
pole view
Rumex
Sorrel
Grain Type: Tricolporate
mid
Eriogonum crocatum
Umbrella Plant
Grain Type: Tricolporate
top
mid
Eriogonum hooveri
Umbrella Plant
Grain Type: Tricolporate
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Alnus rugosa
Alder
Grain Type: Stephanoporate
Notes: Pores arrainged on equator. Compare with Juglans.
mid
Corylus california
Hazel
Grain Type: Triporate
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mid
top
showing trilete scar
Lycopodium spp.
Grain Type: Trilete spore
Notes: Trilete spore. May appear lit from inside. Used as a control in the Berkeley lab.
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