|MadSci Network: Botany|
You ask several interesting questions that may not have been researched. The first reference indicates that most Calochortus are generalists in regard to insect pollinators. You might wish to email the authors with your questions and to ask for a copy of their Calochortus articles. It seems likely that a generalist plant species for pollinators would have an advantage over a specialist species in certain situations. If the specialist species lost its only pollinator, it could be in deep trouble. Losing a single pollinator species for a generalist plant species would not be as serious. On the other hand, a specialist plant species might have a more efficient pollinator than a generalist plant species. To test your hypothesis of why the flower turns red/orange after pollination. Take some cut Calochortus flowers indoors before they open and place them where insects cannot get at them. As a control, hand pollinate some cut flowers. If they do not turn red/orange in unpollinated, then you can establish that pollination causes the change. An alternative explanation is that the red/orange color develops due to senescence whether or not the flower is pollinated. Your questions on whether the red/orange color is due to stored sugars would be more difficult to test. It might require biochemical work. First, you would have to identify the red/orange pigments. It may be an anthocyanin, which are the same type of pigments that are produced in autumn tree leaves as a "sunscreen" (see second reference). References Dilley, James D., Wilson, Paul & Mesler, Michael R. (2000) The radiation of Calochortus: generalist flowers moving through a mosaic of potential pollinators. Oikos 89 (2), 209-222. doi: 10.1034/j.1600-0706.2000.890201.x Lee, D.W. and Gould, K.S. Why leaves turn red. American Scientist 90: 524-531.
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