'Palynology'“ refers to the analysis of organic-walled plant remains, such as pollen. As such, the earliest published study in North America is that of Young (1908), who followed earlier studies in Europe by Pfister (1895), and counted pollen in processed samples of honey. Thus, “actuo“- palynology precedes the study of fossil or “paleo“- palynology in North America.

Two dates might be given for the origin of "paleo-palynology." The first is 1884, when Paulus Reinsch published the results of an acid treatment to free resistant pollen and spores from German coals, after treatment with hydrochloric, hydroflouric, and similar strong acids. The second date for the beginning of palynology is 1917, when Lenart Von Post published the first quantitative (percentages) analysis of the pollen and spore contents of Scandinavian Bogs.

These events followed by over a century the first observation of pollen by Englishman Nehemiah Grew in 1640 (Sarjeant, 2002), using one of the earliest microscopes. And, it was Christian Gottfried Ehrenberg who in 1837 first saw microfossils preserved in sediment (Sarjeant, 1978). It was Reinsch's chemical extraction proceedure, and Von Post's quantification that marked the beginnings of palynology, not just the first discovery of pollen and other microfossils.

The study of paleo-palynology began in North America in 1911, before the word had been coined (Hyde and Williams, 1944), when Reinhardt Thiessen published studies of spores and pollen in thin sections and extractions (Schulze's process) of coal (Thiessen, 1911, 1920; Lyons and Teichmüller, 1995). Alternatively, the illustration of "sponge spicules" by Merrill (1895; see Sarjeant, 1966) were the first observation of what later proved to be dinoflagellates (hystrichosphaerids).

After the sporadic early studies, began a vigorous period of exploratory (Quaternary) palynology during the 1930's. The first application of Von Post's numerical approach was by Finnish palynologist Väinö Auer (1927) working on bogs in southeastern Canada. The earliest study by an American was that of Patricia Draper (1929). Later, in 1929 Ivey F. Lewis and E. C. Cocke (Virginia Tech.) published the analysis of the sediments of Dismal Swamp, Virginia. This was soon followed by Paul B. Sears (1930)(Oberlin College) study of Bucyrus bog and Mud Lake Bog (Sears, 1931); Antioch Bog (Illinois) and Waupaca bog (Wisconsin) by Voss (1931); Lane's (1931) study of the East McCulloch (Ohio) peat; Bowman's (1931) study in Quebec; and in 1932 John E. Potzger (Butler University) published on a northern Michigan bog. The first Ph.D. dissertation on Quaternary palynology was that of John Voss (U. Chicago) (1933) followd by Leonard Richard Wilson (U. Michigan) (1935).

The North American study of palynological morphology began in 1928 with Roger P. Wodehouse's (U. Toronto) first paper and Paul Sears' (1930) illustrated key. In 1934 L.R. Wilson (Coe College, Iowa) published a description of North American Lycopodium spores, and the following year, 1935, Wodehouse published the world's first manual of pollen illustrations.

The year 1939 witnessed the initial Quaternary palynological publications by several scientists who joined Sears, Potzger and Wilson in developing (paleo)palynology in North America -- Murey Buell (N. Carolina State U.), Stanley Cain (U. Tennessee), and Henry P. Hansen (U. Oregon). These three (plus John E. Potzger and Paul B. Sears) were the founders of North American Quaternary palynology. Each went on to become leaders in the nascent conservation movement. To these five could be added L. R. Wilson, who continued his studies of Quaternary sediments (1935, 1938), but whose interest soon turned to older deposits.

Although not the first American to do so (Thiessen, 1911) L.R. Wilson published the first of his many papers on Paleozoic palynology in 1943, and in 1950 Alfred Traverse completed the first Ph.D. dissertation on pre-Quaternary palynology. Also in 1943, Carrol published the first actuo-palynological study of the modern pollen rain. This technique, pioneered by Firbas (1931), provided a powerful tool for interpretation of pollen diagrams by quantifying the relationship between vegetation and the pollen rain it produces.

From 1943 - 1948, Paul Sears (and from 1948-1952, L. R. Wilson) published the Pollen and Spore Circular, the first palynological journal. Although it was mimeographed on coarse recycled paper, its humble pages contain the proposal for the word 'palynology' by Hyde and Williams (1944). Archival collections of the circular exist at the University of Minnesota and University of Arizona palynology palynology laboratories.

During the 1950's palynological research in North America was stimulated by the Pollen and Spore Circular, and through 5 National Pollen Conferences. The first National Converence was hosted by Stanley Cain at Yale University, in 1953. The second was hosted later the same year in Boston, by the AAAS. Three years later, Kathryn Clisby hosted the Third National Pollen Conference at Oberlin College. In 1957 (Penn State) and 1958 (Botanical Society of America Meetings, Palo Alto, California.), Al Traverse hosted the Fourth and Fifth National Pollen Conferences.

Conference Date Location Convenor
First National Pollen Conference Feb., 1953 Yale University Stanley Cain
Second National Pollen Conference Dec., 1953 Boston, Mass. AAAS
Third National Pollen Conference 1956 Oberlin College Kathryn Clisby
Fourth National Pollen Conference 1957 Bot Soc Amer Alfred Traverse
Fifth National Pollen Conference 1958 Palo Alto, California Alfred Traverse

The mid-twentieth century witnessed a diversification of palynology, with the development of aerobiology, pollination ecology, and archeological palynology. Wodehouse's (1945) "Hayfever Plants," followed by Hyde and Adams (1958) "Airborne Pollen," provided the identification tools needed for the development of aeroallergy. Simultaneously, airborne samplers such as May's (1945) cascade impactor, Durham's (1946) gravity sampler, and Hirst's (1952) vacuum sampler made quantitative research possible.

Pollination ecology and “melisso-palynology“ (honey-palynology) share a link through the fertilization of crop plants. Pollen identification and quantification are of minor importance in pollination ecology, which in addition to agricultural applications also concerns the pollination of natural plants (evolutionary ecology). The sexual role of pollen in fertilization was recognized by the ancient Assyrians in 850 B.C. (Wodehouse, 1935). And, the first published North American study of pollination ecology was that of James Logan (1739), Governor of Pennsylvania, who observed that removal of corn (Zea mays) male panicles supressed development of the ears of corn. This agricultural theme was continued in North America by Lovell (1918) and Gray (1857). The study of pollination in natural systems was pioneered by Clements and Long (1923) working at Pikes Peak, Colorado; and it's genetic (evolutionary) implications were pursued by Stebbins (1957, 1970).

In North America, the study of “melisso-palynology“ has been of minor importance compared to Europe, where the pollen content of honey is routinely studied to ensure the nectar source. North American studies (Young, 1908; Todd and Vansell, 1942) paralleled the development in Europe (Erdtman, 1935); however, in North America today filtration and pasteurization remove pollen from commercially-available honey. Whereas in Europe, these practices are less common, and melisso-palynology is an active discipline. (see “session e,“ Domìnguez et al., 2004)

The application of palynology to archeology began with von Post et al.'s (1925) investigations and was developed in Europe by Firbas (1934), Iversen (1941) and Godwin (1944). This aspect of archeological palynology primarily concerns the impact of humans on the natural vegetation as seen in standard (bog and lake) pollen analyses. This approach was adopted by Paul B. Sears (1937, 1950, 1953) for North America including Mexico.

A second aspect of archeological palynology is based on the analysis of sediments from archeological sites. This approach was developed by Geoffrey Dimbleby in Britain during the 1950s, particularly the pollen analysis of soils. It was applied more broadly in North America by Paul Martin and his colleagues (Lindsay 1958; Whitehead, 1959; Martin and Schoenwetter, 1960a, 1960b; Gray and Smith, 1962), by Sears and Roosma (1961) and by Bohrer (1968).

Three elements of the palynology of archeological sites have received particular attention. First, the history of the plant domestication and utilization, which was pioneered by Martin and Schoenwetter (1960a). Second, the palynological investigation of human diet through the analysis of human feces (coprolites) (Martin and Sharrock, 1964; Kelso ,1971; Williams-Dean, 1978). Third, the palynological investigation of artefacts (Hevly, 1964 p. 86,89; Bohrer, 1968; Bryant and Morris, 1986) and the function of site features (Schoenwetter, 1962; Hill and Hevly, 1968.)

The third element of archeological palynology (artefacts), above, is also the approach followed by “forensic palynology“, in which criminal behavior is traced through the analysis of pollen on clothing, automobiles, and other items associated with crimes. Although mentioned in the classical pollen textbooks, case-studies have not been published until recently (see “session f,“ Domìnguez et al., 2004).

Traverse and Sullivan (1983) describe the steady growth of the palynological community in North American during the late 1950's and 1960's. A central event during this period was the First International Pollen Conference, organized by Gerhard O. W. Kremp in Tucson, Arizona, in 1962. Thereafter, North American palynologists such as John Grayson and Herbert Sullivan began to discuss the formation of a North American palynological society.

This formation took place on Dec. 8, 1967 at the Amoco (Pan American) Petroleum Co. in Tulsa, Oklahoma. By a vote of 17 / 14 the 32 persons present christened the new organization the "American Association of Stratigraphic Palnologists." The First Annual Meeting of AASP was held at Louisiana State University, Oct. 17-19, 1968, with a total membership of 188. AASP was joined in representing North American Palynologists by the Canadian Association of Palynologists in 1978.

from: Traverse, A. Sullivan, H.J. 1983 The background, origin, and early history of the American Association of Stratigraphic Palynologists. PALYNOLOGY (7): 7-18.
      1 Delbert E. Potter
      2 Logan L. Urban
      3 James B. Urban
      4 Kenneth M. Piel
      5 Arthur E. LeBlanc
      6 Charles F. Upshaw
      7 Lewis E. Stover
      8 George R. Fournier
      9 Robert L. Tabbert
      10 William F. Von Almen
      11 William S. Hopkins
      12 Mel W. Thompson
      13 D. Colin McGregor
      14 William A. S. Sarjeant
      15 Alfred Traverse
      16 George F. Hart
17 William C. Elsik
18 Graham L. Williams
19 Earl T. Peterson
20 Fritz H. Cramer
21 John F. Grayson
22 Paul W. Nygreen
23 Howard Simpson
24 Robert T. Clarke
25 Mart P. Schemel
26 David R. Mishell
27 William C. Myers
28 Richard W. Hedlund
29 Bernard L. Shaffer
30 Herbert J. Sullivan
31 Dennis R. Logan
32 O. Ben Bourn

Founders of AASP outside Pan Am Research Building
December 9, 1967

Jansonius and MacGregor (1995) trace the development of palynological literature from 1840 - 1990, based on records compiled by the Canadian Geological Survey. The numbers of papers published per year held study after the 1930's at 10 - 20 per year. After 1950, the rate climbed steadily to a peak of 450 - 500 articles and reports per year from 1975 - 1985, and has held steady or declined thereafter.

Origin of AASP adapted from:

  • Traverse, A. Sullivan, H.J. 1983 The background, origin, and early history of the American Association of Stratigraphic Palynologists. PALYNOLOGY (7): 7-18.


    Auer, V. 1927.
    Stratigraphical and morphological investigations of peat bogs of southeastern Canada. Comm. ex. Inst. Quaest. Forest Finlandiae editae 12: 1-62.

    ________ 1927.
    Botany of interglacial peat beds of Moose River Basin Geol. Surv. Canada Summary Report 1926, C: 45-47.

    Bohrer V.L. 1968.
    Paleoecology of an archaeological site near Snow Flake, Arizona. Ph.D. dissertation, Univ. Arizona.

    Bowman P.W. 1931.
    Study of a peat bog near the Matamek River, Quebec, Canada, by the method of pollen analysis. Ecology 12: 694-708.

    Bryant, V.M. 2001.
    Pollen Contents of Honey. Canadian Association of Palynologists Newsletter 24(1):10-24. Available online at viewed 7/04.

    Bryant V.M. and Morris, D.P. 1986.
    Uses of ceramic vessels and grinding implements: the pollen evidence. pp. 489-500 IN: Morris, D.P. (ed.) Archeological investigations at Antelope House. National Park Service Publ. Archaeology 19.

    Buell M.
    1939 Peat formation in the Coarlina Bays Bulletin Torrey Botanical Club 66: 483-487.
    1945a Late Pleistocene forests of southereastern North Carolina Torreya 45: 117-118.
    1945b The age of Jerome Bog, "A Carolina Bay" Science 103: 14-15
    1946 Jerome Bog, a peat-filled "Carolina Bay" Bulletin Torrey Botanical Club 73: 24-33.

    Cain S.E. 1939.
    Pollen analysis as a paleo-ecological researach method. Botanical Review 5: 627-654.
    1940. The identification of species in fossil pollen of Pinus by size-frequency determination. American Journal of Botany 27: 301-308.
    1944. Pollen analysis of some buried soils, Spartanburg County, South Carolina. Bulletin Torrey Botanical Club 71: 11-22.
    1944. Size-frequency characteristics of Abies fraseri pollen as influenced by different methods of preparation. American Midland Naturalist 31: 232-236.

    Carroll, G. 1943.
    The use of bryophyte polsters and mats in the study of recent pollen deposition American Joural Botany 30: 361-366.

    Clements, F.E. and Long, F.L. 1923.
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    Cocke, E.C., Lewis, I. F., and Patrick, R. 1934.
    A. further study of Dismal Swamp peat. Am. Journ. Bot. 21: 374-395.

    Dimbleby, G.W. 1955.
    Pollen analysis as an aid to the dating of prehistoric monuments. Proceedings of the Prehistoric Society 20: 231-236.

    Domìnguez, E., Ubera, J.L., Diez, M.J., Galàn, C., Guarro, J., la Serna, I. Ruiz-Zapata, B., Infante, F., Romero, R., López-Pàrraga, E. 2004.
    XI International Palynological Congress. Polen vol. 4, 601 p.

    Draper, P. 1929. A comparison of pollen spectra of old and young bogs in the Erie Basin. Proceedings of the Oklahoma Academy of Science. 9: 50-53.

    Durham, O.C. 1946.
    The volumetric incidence of atmospheric allergens, IV. A proposed standard method of gravity sampling, counting and volumetric interpolation of the results. Journal Allergy 17: 79.

    Faegri, K. and Van der Pijl, K. 1979.
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    Fribas, F. 1931.
    Uber die bestimmung der walddichte und der vegetation waldloser giviete mit hilfe der pollenanalyse. Planta 22:109-146.
    ________ 1935.
    Über die wirksamkeit der natürlichen verbretungsmittel der Waldbäume. Natur u. Heimat 6: 65 - 73.

    Godwin, H. 1944.
    Neolithic forest clearance. Nature 143: 511-513.

    Gray, A. 1857.
    Naudin on the genus Cucurbita. American Journal of Science and Arts (ser.2) 24: 440-441.

    Gray J. and Smith W. 1962.
    Fossil pollen and archaeology. Archaeology 15: 16-26.

    Hansen, H. P. 1939.
    Pollen analysis of a bog in northern Idaho American Journal Botany 26: 225-228.
    ________ 1939
    Pollen analysis of a bog near Spokane, Washington Bulletin Torrey Botanical Club 66: 215-220
    ________ 1939.
    Paleoecologicay of a central washington bog Ecology 20: 563-568.
    ________ 1940.
    Paleoecology of a montane peat deposit at Bonaparte Lake Washington Northwest Science 14: 60-68.

    Hevly, R.H. 1964.
    Pollen analysis of Quaternary archaeological and lacustrine sediments from the Colorado Plateau. Ph.D. dissertation, Univ. Arizona.

    Hill, J.N. and Hevly, R. H. 1968.
    Pollen at Broken K Pueblo: some new interpretations. American Antiquity 33: 200-210.

    Hirst, J.M. 1952.
    An automatic spore trap. Ann. Appl. Biol. 39, 257– 265.

    Hyde, H.A. and Williams, D.A. 1944.
    The right word. Pollen Science Circular. No. 8 p. 6.

    Hyde, H.A., Adams, K.F. 1958.
    An atlas of airborne pollen grains. Macmillan and Co. Ltd., London.

    Iversen, J. 1941.
    Landnam i Danmarks stenalder Danmarks Geol. Unders. II Raekke 66:1-68

    ________ 1956.
    Forest clearance in the Stone Age. Scientific American. 194: 36-41.

    Jansonius, J. and McGregor, D.C. 1996.
    Introduction, Palynology: Principles and Applications AASP Foundation.

    Kelso G.K. 1971.
    Hogup Cave, Utah: Comparative pollen analysis of human coprolites and cave fill. Ph.D. dissertation, University of Arizona.

    Lane, G. 1931.
    A preliminary pollen analysis of the East McCulloch peat. Ohio Journal of Science 30: 205-217.

    Lewis, I.F. and Cocke, E.C. 1929.
    Pollen analysis of Dismal Swamp peat Journal Elisha Mitchell Scientific Society 45: 37-58.

    Lindsay, A. J., Jr. 1958.
    Fossil pollen and its bearing on the archeology of the Lehner mammoth site. M.S. thesis, Univ. of Arizona, Tucson.

    Logan, J. 1739.
    Experiments and considerations of the generation of plants. London.

    Lovell, J.H. 1918.
    The flower and the bee. Scribner's, New York.

    Lyons, P.C. and Teichmüller, M. 1995.
    Reinhardt Thiessen (1867-1938); pioneering coal petrologist and stratigraphic palynologist. p. 149-161 In: P. C. Lyons, editor. Historical perspective of early twentieth century Carboniferous paleobotany in North America. Memoir - Geological Society of America 185.

    Martin, P. S. and Schoenwetter, J. 1960a.
    Arizona's oldest cornfield. Science, 132: 33-34.

    Martin, P. S. and Schoenwetter, J. 1960b.
    Pollen stratigraphy of a great kiva from Chaco Canyon. Geoscience Department, Univ. of Arizona, Tucson.

    Martin, P.S. and Sharrock, F.W. 1964.
    Pollen analysis of prehistoric human feces: a new approach to ethnobotany. American Antiquity, 30: 168-180.

    May, K.R. 1945. The cascade impactor: an instrument for sampling coarse aerosols. Jour. Sci. Instrum. 22: 187-195.

    Merrill, J. A. 1895.
    Fossil sponges of the flint nodules in the Lower Cretaceous of Texas. Harvard Collections, Museum of Comparative Zoology Bulletin 28, 1–26.

    Pfister, R. 1895.
    Versuch. Einer Mikroskopie des Honigs. Forschungsbereich Lebensmittel. Bez. Hyg. Pharm. 2 (1): 1-9; 2 (2): 29-35.

    Potzger, J.E. 1932.
    Succession of forests as indicated by fossil pollen from a northern Michigan bog. Science 75: 366.
    ________ 1947.
    Pollen profile from a Texas bog Ecology 28: 274-280
    ________ 1954.
    Pollen study from two bogs in Texas Ecology 35: 462-466.
    Potzger J. E. and B. C. Tharp
    1943 Pollen record of Canadian spruce and fir from Texas Bog Science 98: 584

    Reinsch, P. 1884.
    Micro-Paleophytologia Formationis Coarbonifera. Erlangen 1:1-80; 2:1-56.

    Sarjeant, W.A.S. 1978.
    Hundredth year memorium: Christian Gottfried Ehrenberg 1795-1877. Palynology 2: 209-211

    W.A.S. Sarjeant, 1966.
    The supposed "sponge spicules" of Merrill, 1895, from the Lower Cretaceous (Albian) of Texas. Breviora, Museum of Comparative Zoology, Harvard, no. 242, pp. 1-15.
    ________ 2002.
    'As chimney-sweeps, come to dust': a history of palynology to 1970. pp. 273-327 In: Oldroyd, D. R. The earth inside and out: some major contributions to geology in the twentieth century. Geological Society (London) Special Publication no. 192.

    Schoenwetter, J. 1962.
    The pollen analysis of eighteen archaeol sites in Arizona and NM. In: Martin, P. S., et al., Chapters in the prehistory eastern Arizona, I. Chicago Natural History Museum, Fieldiana: Anthro. 53: 168-209.

    Sears, P.B. and Couch, G.C. 1932
    Microfossils in an Arkansas peat and their significance Ohio Journal Science 32: 63-68.

    Sears, P.B. 1930.
    A record of postglacial climate in North America. Ohio Journal of Science 30: 205-217.
    ________ 1930.
    Common fossil pollens of the Erie Basin. Botanical Gazette 89: 95-106.
    ________ 1931.
    Pollen Analysis of Mud Lake Bog in Ohio Ecology 12: 650-655.
    ________ 1932.
    Glacial and Postglacial Vegetation. Botanical Review 1(2): 37-51.
    ________ 1935.
    Types of North American Pollen Profiles. Ecology 16: 488-499.
    ________ 1937.
    Pollen analysis as an aid in dating cultural deposits in the United States. p. 61-66 In: MacCurdy, G. G. (ed.), Early Man. As Depicted by Leading Authorities at the International Symposium, The Academy of Natural Sciences, Philadelphia. J. B. Lippincott Co., London,
    ________ 1942.
    Postglacial migration of five forest genera. American Journal Botany 29: 584-691.
    ________ 1950.
    Pollen Analyses In Old and New Mexico. GSA Bulletin 61: 1171.
    ________ 1953.
    Climate and civilization. pp. 34-50 In: Shapley, H. (ed.) Climatic Change: Evidence, Causes, and Effects. Harvard Univ. Press, Cambridge.

    Sears, P.B. and Roosma, A. 1961.
    A climatic sequence for two Nevada caves. American Journal of Science 259: 669-678.

    Stebbins, G.L. 1957.
    Self fertilization and population variability in the higher plants. American Naturalist 91:337–354.

    ________ 1970.
    Adaptive radiation of reproductive characteristics in angiosperms. I. Pollination mechanisms. In: Annual Review of Ecology and Systematics, Vol. 1.

    Thiessen, R. 1911.
    Plant remains composing coals (abst.) Science (n.s.) 33: 551-552.

    ________ 1920.
    Structure in Palaeozoic bituminous coals. U. S. Bureau Mines Bull. 117: 1 - 296.

    Traverse, A. 1955.
    Pollen analysis of the Brandon Lignite of Vermont. U. S. Bur. Mines Rept. of Invest. 5151.

    Traverse, A., and H. J. Sullivan. 1983.
    The background, origin, and early history of the American Association of tratigraphic Palynologists. Palynology 7: 7-17.

    von Post, L. 1917
    Om skogstradpollen i sydsvenska tormfmosselagerfolker. Geologiska Foreningens i Stockholm Forhandlingar 38: 384-390.

    von Post, L., von Walterstorff, A. and Lindquist, S. 1925.
    Bronsaldersmanteln fran Gerumsberget i Vastergotland. Kungliga Vitterhets, Historie, och Antikvitetsakademiens, Monografiserie 15: 1-39.

    Voss, John. 1931.
    Preliminary report on the paleo-ecology of a Wisconsin and an Illinois bog. Transactions Illinois State Academy Science 24(2): 130-136.

    Voss, John. 1933.
    Post-glacial migration of forests in Illinois, Wisconsin and Minnesota. Thesis (Ph.D.) University of Chicago, Dept. of Botany (QE999 Voss)

    Whitehead, D. R. 1959.
    Fossil pollen and spores from the LaDaisKa Site, CO. In: Irwin, H. J., and Irwin, C. C., Excavations at the LaDaiska Site in the Denver, Colorado, area. Denver Museum of Natural History Proceedings 8, 114-118.

    Williams-Dean, G. 1978.
    Ethnobotany and cultural ecology of prehistoric man in southwest Texas. Ph.D. Thesis, TX A&M Univ., College Station.

    Wilson, L.R. 1932. The Two Creeks Forest bed, Manitowoc County, Wisconsin: Wisconsin Academy of Science, Arts, and Letters Transactions 27: 31-46.
    ________ 1934.
    The spores of the genus Lycopodiuim in the United States and Canada. Rhodora 36: 13-19.
    ________ 1935.
    The postglacial history of vegetation in northwestern Wisconsin. Ph.D. dissertaion, University Michigan, Maddison 83 p.
    ________ l935.
    Lake development and plant succession in Vilas County, Wisconsin. Ecological Monographs 5: 207 - 247.
    ________ 1936.
    Further fossil studies of the Two Creeks Forest bed, Manitowoc County, Wisconsin. Torrey Botanical Club Bulletin 63: 317 - 325.
    ________ 1938.
    The postglacial history of vegetation in northwestern Wisconsin. Rhodora 40: 137 - 175.

    ________ 1943.
    Elater-bearing spores from the Pennsylvanian strata of Iowa. American Midland Naturalist 30: 513-523.

    Wilson, L. R. and A. T. Cross. 1943.
    A study of plant microfossil succession in the bottom deposts of Crystal Lake, Vilas County, Wisconsin, and the peat of an adjacent bog. American Journal Science 241: 307-315.

    Wodehouse, R.P. 1928.
    The phylogenetic value of pollen grain characters. Annals of Botany 42: 891-934.

    ____________ 1935.
    Pollen Grains, McGraw-Hill New York 574 p.

    ____________ 1945.
    Hayfever plants. The Chronica Botanica Co., Waltham, Mass 245 p.

    Young, W.J. 1908.
    A microscopical study of honey pollen. U.S. Bureau Chemistry Bulletin 100:1-93.

    Owen Davis last update 7/04