Arctostaphylos pungens
© NatureSongs, Verde Valley

Vaccinium stamineum L.

Arctostaphylos sp.
University of Arizona

The Ericaceae (heath family) is a cosmopolitan family (over 3000 species) including herbs, shrubs, and trees with evergreen, alternate, simple leaves. The flowers are red to white, urn- to bell-shaped, and the anthers have pores for pollen release. The fruits may be capsules, berries or drupes.

Pollen light micrograph:
With a few tricolporate (monad) exceptions, Ericaceae pollen grains are tetrahedral tetrads of 4 cells, ca. 20-40 µm, with a nearly-spherical to irregular outline. Each cell is a tricolporate grain, with the pore area of adjacent grains in contact. The surface sculpturing is psilate to reticulate.

Pollen scanning electron micrograph (SEM)
Note the scabrate surface and pores.

Production and Dispersal:
Low production, moderate dispersal.

Well preserved.

Fossil Occurrence:
Present from the Oligocene at latest (Tsudy & Scott, 1969) onward, and becoming abundant, particularly in western Europe, during the Pliocene (Traverse 1988). Moderately common in the Subatlantinc of Europe in heat areas. Sporadically found in coastal areas of Oregon and California, and chaparral areas of California and Arizona.

    Oldfield, F. 1959
    The pollen morphology of some of the west European Ericales. Preliminary descriptions and a tentative key to their identification. Pollen et Spores 1: 19-48.

    Traverse, A. 1988.
    Paleopalynology. Allen and Unwin. 600 p.

    Tsuchdy, R.H. and Scott, R.A. 1969.
    Aspects of palynology. Wiley Interscience.

    Ueno, J. 1962.
    Palynological notes on Ericaceae and Pyrolaceae from Japan and its neighbors. Acta Phytotax Geobot. 20;101-112.

Owen Davis 3/01