WORLD LIST OF PLANTS WITH EXTRAFLORAL NECTARIES

Including extranuptial nectaries, circumfloral nectaries, posfloral nectaries and foliar nectaries

Because ferns do not have flowers, ferns are listed separately
WORLD LIST OF FERNS WITH FOLIAR NECTARIES

Foliar nectaries have not been reported for the Gymnosperms

Compiled by Kathleen H. Keeler, Professor Emerita, School of Biological Sciences, University of Nebraska-Lincoln

I began this list in the late 1970’s but it grew too long to publish and so went into a drawer. The web allows me to put it up in usable format and to update continually, which is a big improvement over a print publication.

I am using the term extrafloral nectaries very broadly here. The goal is to include all glands which produce water and sugars, but do not function to attract and reward pollinators, what Delpino (1886) called extranuptial nectaries. However, the function of only a very few extrafloral nectaries have been studied in detail, whether on the leaves, stems or external to the corolla. Furthermore, some leaf nectaries feed pollinators (e.g., Acacia terminalis , Knox et al. 1985). So for now this list seeks to include all nectaries outside of the calyx and makes no claims about function.

Issues in a list of extrafloral nectaries include

1) species not yet seen;

2) nomenclatural confusion, both when names change and because the original specimen was misidentified;

3) mistaking other glandular structures for nectaries

4) recognizing nectary function when there are no surface features

Ideally the presence of an extrafloral nectary is established by demonstrating that the substance produced contains sugars. Without sugars it is a hydathode. A second line of evidence is the attraction of nectar-feeders, especially ants but also wasps and beetles. Feeding is hard to prove, but repeated stopping in the same position at the same spot on the plant is consistent with nectar production. A third approach is to look for nectary structures—raised glands, recessed basins. If some members of the genus or family have extrafloral nectaries in that position, e.g. petiolar nectaries in Ipomoea , I have included other species with the same structures in the same or similar locations.

Angiosperms are arranged alphabetically by genus within the families recognized by the Angiosperm Phylogeny Working Group [Stevens 2001]. The Angiosperm Phylogeny Webpage does not search well by genus: if you need to find where I have put a genus and do not know the family, search on Kew Garden 's web page: http://www.kew.org/data/vascplnt.html

The Ferns are listed separately because, lacking flowers, they don’t have extrafloral nectaries…Nevertheless some have leaf nectaries [fern nectaries]

The updating is ongoing.

Comments, clarifications and new information are welcome.

I am presently trying to improve the format, so the way the pages look will gradually change. However, I will not change the "updated" date unless the scientific information changes.

Kathy Keeler

kkeeler1@unl.edu

February 6, 2008

Cite these pages as K.H.Keeler 2008 World list of angiosperms with extrafloral nectaries