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Title: Evolution of apetaly in the cosmopolitan genus Stellaria

Apetaly is widespread across distantly related lineages of flowering plants and is associated with abiotic (or self‐) pollination. It is particularly prevalent in the carnation family, and the cosmopolitan genusStellariacontains many lineages that are hypothesized to have lost petals from showy petalous ancestors. But the pollination biology of apetalous species ofStellariaremains unclear.


Using a substantial species‐level sampling (~92% of known taxonomic diversity), we describe the pattern of petal evolution withinStellariausing ancestral character state reconstructions. To help shed light on the reproductive biology of apetalousStellaria, we conducted a field experiment at an alpine tundra site in the southern Rocky Mountains to test whether an apetalous species (S. irrigua) exhibits higher levels of selfing than a sympatric, showy petalous congener (S. longipes).


Analyses indicated that the ancestor ofStellariawas likely showy petalous and that repeated, parallel reductions of petals occurred in clades across much of the world, with uncommon reversal back to showy petals. Field experiments supported high rates of selfing in the apetalous species and high rates of outcrossing in the petalous species.


Petal loss is rampant across major clades ofStellariaand is potentially linked with self‐pollination worldwide. Self‐pollination occurs within the buds inS. irrigua, and high propensities for this and other forms of selfing known in many other taxa of arctic‐alpine habitats may reflect erratic availability of pollinators.

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Author(s) / Creator(s):
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Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
American Journal of Botany
Page Range / eLocation ID:
p. 869-882
Medium: X
Sponsoring Org:
National Science Foundation
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