Incompatibility Between the Dimorphic Flowers of Collomia grandiflora, a Cleistogamous Species

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Science  17 Feb 1984:
Vol. 223, Issue 4637, pp. 695-696
DOI: 10.1126/science.223.4637.695


The cleistogamous species Collomia grandiflora produces dimorphic cross-incompatible flowers on a single plant. The open or chasmogamous flower has smaller, flask-shaped stigmatic papillae, larger pollen grains, longer styles, and faster pollen tube growth rates down the style than the closed or cleistogamous flower. In intermorph crosses, pollen tube growth rates are greatly decreased and fertilization does not occur.