Reproduction and attracting mates: Flowers (including zygomorphy, pollination, flowering time)

Questions Discussions: Any questions? Maria M: posting paper and questions for this week Jon: will be picking a paper to post for next week Peter Stevens is taking students around Orchid house at gardens at 10 am probably on Saturday. Let him or me know if you are interested. Any questions?

What’s a flower? What’s it for?

Ferns Gymnosperms Angiosperms

Flower evolution 130-250 mya Modified leaves (why?)

What’s a flower? What’s it for? Reproductive structure of angiosperms: Heterosporangiate typically consisting of androecium, gynoecium, usually surrounded by a perianth and borne on an axis or receptacle

Flower morphology Pedicel Flower parts in whorls: (4,5’s or 3’s) Calyx (sepals), Corolla (petals), Androecium (stamens with anther, filament), Gynoecium (pistils with stigma, style, ovary)

Symmetry Actinomorphic (radially symmetric) vs zygomorphic (1 bisecting line of symmetry) Asymmetric: uncommon (Cannanceae, Marantaceae)

Flower vs. Inflorescence Cercidiphyllum

Breeding systems: outcrossing and inbreeding Spatial: Flower: perfect (both sexes) vs. imperfect (1 sex) Plant: monoecious (1 sex) vs. dioecious (both sexes) Heterostyly

Breeding systems: outcrossing and inbreeding Temporal: Dichogamy Protandry: stamens before carpels Protogyny: carpels before stamens

Pollination syndromes Animal: Insects, birds, bats Rewards: Nectar, pollen, fragrance, oils Attract pollinators: Scent, color patterning, mimicry (Orchidceae) Abiotic: Wind and water Self pollinated, Cleistogamous

Evolution of oil production and collection Renner and Schaefer. 2010. Phil. Trans. R. Soc. B. 365:423-435. Bees collect oil for larvae and pollinate flowers Question: When and how often oil-offering flowers and oil-foraging bees evolved?

Oil and bees Renner and Schaefer. 2010. Phil. Trans. R. Soc. B. 365:423-435. Question: When and how often oil-offering flowers and oil-foraging bees evolved? Oil flowers evolved at least 28 times and lost 36-40 times. Oldest just after the K/T boundary65 mya in America (Melpighiaceae) and Africa (Curcurbitaceae, and Laurasia (Myrsinaceae) taxa Bees evolved oil foraging at least 7 times with earliest at least 53-56 Mya (but probably older)

Phylogenies

Build ups

Evolution of floral morphology

Evolution of floral morphology

Question Is flower symmetry associated with changes in speciation rates mediated via pollinators?

Question Is flower symmetry associated with changes in speciation rates mediated via pollinators? Suggest bilaterally symmetrical flowers can restrict pollinator access to flowers, direct pollen placement, and lead to greater reproductive isolation Predict that bilaterally symmetrical flowers have higher speciation rates than radially symmetrical flowers

Question Is flower symmetry associated with changes in speciation rates mediated via pollinators? Corolla symmetry data for animal pollinated families from the literature Sister-group comparisons (40 zygomorphic clades and 19 comparisons) Building an angiosperm tree and mapping on zygomorphy Looking for the actinomorphic sister Getting number of species in family from literature

Evolution of floral morphology Zygo-Actino species * = Actino † = Zygo

Question Is flower symmetry associated with changes in speciation rates mediated via pollinators? In 15/19 comparisons zygomorphic clade was more diverse than actinomorphic clade