[randywebb]

Some wind-pollinated plants use the sharpness of the bend in tubes that lead to the female sex organ to control the size pollen that gets in to mate. The bends slow the air and make foreign species pollen drop out if it is too big & heavy. At a different place along the tube, the process is reversed and the too-small pollen is sent rushing into oblivion, and the right sized "good stuff" drops down onto the plants' - um - "egg." et voila.

I don't have those reprints anymore, but did a quick search and found this interesting article. You will _enjoy_ adapting this research to your car....

Science 30 July 1982:
Vol. 217. no. 4558, pp. 442 - 444
DOI: 10.1126/science.217.4558.442

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Articles

Pollination and Airflow Patterns Around Conifer Ovulate Cones
KARL J. NIKLAS 1 and KYAW THA PAW U 2

1 Section of Plant Biology, Cornell University, Ithaca, New York 18453
2 Department of Agronomy, Purdue University, West Lafayette, Indiana 47907

Wind-tunnel studies indicate that the geometry of Pinus ovulate cones may enhance the probability of pollen entrapment by aerodynamically predetermining airflow patterns around scale-bract complexes. Pollination experiments reveal that pollen from a particular species has the highest probability of reaching the ovules of its own species. The phenomenon of species-specific pollination appears to be related to the specific morphometry of scale-bract complexes and the terminal settling velocity of pollen of the same species. These data are interpreted as evidence for a reciprocity between the aerodynamic characteristics of airborne pollen and ovulate cones of some conifer species.