Function of heliocentric positioning of flowers

[Kenelm Philip]

Thomas Yancey asked about the functional purpose of heliocentric
positioning of flowerheads.

There was some discussion of this topic in Peter Kevan's thesis (High
Arctic Insect-Flower Relations, 1970) with regard to Ellesmere Island.
Two advantages to the plants involved were implied: 1. An appreciably
higher temperature of the stigmas (lying near the focal point of the
reflector formed by the flower petals) in a geographic region with a
very low heat budget, which may have helped maturation, and 2. Attracting
insects (which like to bask in the sun-warmed flowers) which aid in
pollination.

                                                        Ken Philip
fnkwp at aurora.alaska.edu