Science Fair Project Encyclopedia
About 30 species, including:
Pyrola is a genus of evergreen herbaceous plants in the family Pyrolaceae. The species are commonly known as wintergreen, a name shared with several other related and unrelated plants (see wintergreen for details). They are native to northern temperate and Arctic regions.
These wintergreens are characterised by the production of oil of wintergreen which gives the bruised plants a familiar "medicinal" smell. They are rather small plants with a rosette of simple orbicular or ovate leaves, with a flower stem bearing generally rather lax racemes of simple white, cream or pink flowers. The immediate distinguishing feature of Pyrola species is the flower style which is often curved, sticks out beyond the petals and is expanded below the stigma which iself is branched into several lobes. To the casual observer the flower appears to have a small bell-clapper sticking out.
They are distibuted across northern temperate and arctic Europe, Asia and North America. In North America they also occur down the western mountains south to California. Some populations in New England may be introductions by early European settlers.
Pyrolaceae, as part of the Ericales produce pollen in anthers which open by apical pores. The pollen itself is prouced in tetrads and is rather sticky. Not surprisingly, wintergreens are insect pollinated, most commonly by flies. The rather large and complex stigma may be an adaptation to ensure that small insects carrying pollen have an attractive landing place. The flowers are produced in the summer and the rather inconspicous greenish seed capsules are produced in the autumn. The seeds are numerous and very small.
Wintergreens prefer dampy and shady locations in woods or in dune slacks. They are often rather local in ditribution but can be locally common especially in their more northen locations.
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