Morphology and Distribution of Petiolar Nectaries in Ipomoea (Convolvulaceae)

Authors

Kathleen H. Keeler, University of Nebraska - LincolnFollow
Robert B. Kaul, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

9-1979

Citation

American Journal of Botany (September 1979) 66(8).

Comments

Copyright 1979, Botanical Society of America. Used by permission.

Abstract

The distribution of petiolar nectaries in 24 species of Ipomoea was investigated. Petiolar nectaries were found on 12 species (8 new reports, 4 confirmations of previous reports) and quoted from the literature as being found on 3 other species; they were absent from 9 species investigated. The structure of petiolar nectaries in the genus ranges from simple beds of superficial nectar-secreting trichomes (1 species), to slightly recessed "basin nectaries" (8 species), to "crypt nectaries," which are structurally the most complex extrafloral nectaries known (3 species). (Structures were not determined for 3 species.) Petiolar nectaries are present in all subgenera, but all crypt nectaries occur in the same section (Eriospermum). Species with extrafloral nectaries tend to be perennial; species lacking extrafloral nectaries tend to be annual. There is no relationship between temperate or tropical habitat and presence of nectaries.