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Birch Type
Family, Genus: Betulaceae, Betula
| Size | 23 - 32 um | ||
| Shape | circular in polar view | ||
| Exine | 1.0 - 1.5 um thick | ||
| Intine | less than 1 um except for below pores | ||
| Pores | triporate, pores annulate or aspidate, some pollen annulus splits giving the appearance of furrows | ||
| Sculpting | rugulate with scabrate elements | ||
| Bloom Period | beginning of April to end of May | ||
| Allergenicity | moderately allergenic |
Thumbnails:
Birch Birch birch birch with split annuli
Dr. M. Davis images:
Yellow Birch
References:
Bassett, John, Clifford Crompton and John Parmelee. An Atlas of Airborne Pollen Grains and Common Fungus Spores of Canada. Canada Department of Agriculture, 1978.
Jelks, Mary, M.D. Allergy Plants that Cause Sneezing and Wheezing. World Wide Printing, Tampa, 1986.
Kapp, Ronald O. Pollen and Spores, Second Edition. The American Association of Stratigraphic Palynologists Foundation, 2000.
Lewis, Walter H., Prathibha Vinay and Vincent E. Zenger. Airborne and Allergenic Pollen of North America. The Johns Hopkins University Press, Baltimore and London, 1983.
page created by: Brian Hoffman