Chenopod pollen.
Grass pollen
Ragweed pollen
Sage and mugwort pollen. Grain is 20-30 μm, round to triangular in shape, and has three
... [Show More] prominent furrows
...
Cocklebur pollen.
Nettle pollen
Plantain pollen. "doughnut"
...
Ash pollen. Exine has net-like (reticulate) pattern. In ash, the net pattern is fine; but, in olive and privet, the net pattern is coarse and quite apparent.
Olive and privet have three furrows.
...
Dock or sorrel pollen. with characteristic starch
inclusion granules. Furrows are long, almost reaching the poles
...
Birch pollen (Birch, Alder, Hazelnut, and Hornbeam). Three pores (triporate) protruding from the surface, each of which contains a collar (oncus). May appear like a lemon, if only two pores are visible
...
Oak pollen (Oak, Beech, and Chestnut (Fagaceae)). Oak pollen is triangular-shaped with three germinal furrows that appear as white "pie slices" slightly protruding from the surface.
...
Sycamore pollen. Round grains, with three furrows and a thin exine that is finely reticulate
...
Maple and Box Elder (Aceraceae) pollen. Grains contain three furrows, like oak; but, are generally round and may have a "beach ball" appearance (Figure 11-18).
...
Sweetgum (Hamamelidaceae) pollen. Periporate, with 12-20 pores per grain that often bulges, suggesting a "soccer ball" appearance.
...
Elm pollen. American elm pollinates in the spring, whereas several other elms pollinate in the fall. Four to sevterm-34en (usually five) oval-shaped pores and may appear pentagonal. Outer surface appears wavy or undulating
...
(A) Mountain cedar pollen with disrupted exine; (B) intact mountain cedar pollen. Thick intine with stellate cytoplasmic contents and an exine, which can break and look like Pac-Man (Figure 11-14).
...
Poplar, Willow, and Cottonwood (Salicaceae) pollen. Poplar and cottonwood have round grains, each with an outer surface that is granular and often appears "cracked" or "flaky" (Figure 11-20); but, there are no furrows. By contrast, willow has three furrows and a reticulate pattern on the pollen wall. Willows are entomophilous and not considered allergenically important; however, they are medically important since aspirin is made from their bark. Poplars are anemophilous and produce significant allergenic pollen throughout North America.
...
Walnut, Hickory, and Pecan (Juglandaceae) pollen. Walnut is periporate, with 9-15 slightly raised germinal pores; hickory and pecan are indistinguishable, with each containing three nonprotruding pores (Figure 11-23).
...
Pine pollen. Bladders give the impression of a child's Mickey Mouse cap
...
Mulberry (Moraceae). Grains are small (i.e., 11-20 μm), thin-walled, and usually diporate with onci, giving the appearance of a light, pinkish lemon (Figure 11-22). Pores are slightly raised or aspirated ("shield-shaped").
...
Mimosa, Acacia, Locust, and Mesquite (Leguminosae). Acacia pollen. Pollen grains may exist as monads or polyads, with the polyads usually having either 4 or 16 quadrangular grains in a group (Figure 11-24).
... [Show Less]