Erodium cicutarium (Geraniaceae)


Erodium cicutarium
G.J.West


furrow and pore
O.K.Davis


sculpture, polar area, LM
O.K.Davis


sculpture, SEM
El Oqlah (?)

Plant:
Native of Europe and Asia, now introduced throughout temperate regions of both hemispheres. A common weed throughout North America. Plant a prostrate rosette with bipinnatifid leaves up to 30 cm. Flowers purple, Fruit a narrow, beaked capsule, developing into two twisted halves.

Pollen light micrograph:
Erodium cicutarium pollen grain is oblate, tricolporate, striate - reticulate, > 57 µm (El Oqlah 1983:392; West 1993). A member of the eurypalynous Geraniaceae family, it can be characterized by its ornamentation and sculpturing patterns. Bortenschlager (1967) and El Oqlah (1983) divide the Geraniaceae into various pollen types and subtypes. According to their classification scheme, E. cicutarium is a type 2 (El Oqlah, 1983), and is subtype "E" and "F" of Bortenschlager (1967). The striate-rugulate pattern overlies a reticulate pattern formed by expansion and coalescing of the columella. E. cicutarium pollen grains are suboblate spheroidal trizonocolpate grains that have a very thick semitectate exine. Sculpturing consists of variously arranged course parallel-sided long and short muri. The interwoven muri form various reticulate - rugulate - striate patterns (Moore et al. 1991:130, Plate 71 e, f).


TYPE 1
El Oqlah


E. corsicum SUBTYPE
Bortenschlager "D"


E. gruinum SUBTYPE
Bortenschlager "E"


E. pachyrhizum SUBT
Bortenschlager "F"

with baculate processes reticulate - rugulate striate striate - rugulate
E. texanum E. botrys
E. macrophyllum
E. malacoides
E. moschatum
E. texanum
E. cicutarium E. cicutarium
E. macrophyllum

Production and Dispersal:
Production and dispersal are low. The showey flowers indicate animal pollination. The pollen is not know from aeorallergy counts.

Preservation:
The very thick walls provide excellent preservation. They are so thick that long acetolysis makes the grains opaque.

Fossil Occurrence:
In western North America this Eurasian native is encountered in historic age deposits and it is thought to be one of the earliest introduced species of plants to be found throughout most of California (Mensing and Byrne, 1998).

References:
    Bortenschlager, Sigmar. 1967.
    Vorlaufige Mitteilungen zur Pollenmorphologie in der Familie der Geranianceen und Ihre Systematische Bedeutung. Grana Palynologica 7(2-3):400-468.

    El Oqlah, A. A. 1983.
    Pollen Morphology of the Genus Erodium L'Herit. In the Middle East. Pollen et Spores 25(3-4):383-394.

    Mensing, S. 1998.
    560 years of vegetation change in the region of Santa Barbara, California. Madroño 45: 1-11.

    Mensing, S. and Byrne, R. 1998.
    Pre-mission invasion of Erodium cicutarium in California. Journal of Biogeography 25: 757-762.

    Moore, P. D., Webb, J. A. Webb, and Collinson, M.E. 1991.
    Pollen Analysis, 2nd edition. Blackwell Scientific Publication, London. Pp. 216

    West, G. James. 1993.
    Early Historic Vegetation Change in Alta California: The Fossil Evidence. In David H. Thomas, Editor, Columbian Consequences, Volume 1 Archaeological and Historical Perspectives on the Spanish Borderlands West. pp. 333-348. Smithsonian Institution Press, Washington.

Links

Owen K. Davis 12/99