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Ants disperse oak galls of some cynipid wasp species similarly to how they disperse seeds with elaiosomes. We conducted choice assays in field and laboratory settings with ant-dispersed seeds and wasp-induced galls found in ant nests and found that seed-dispersing ants retrieve these galls as they do myrmecochorous seeds. We also conducted manipulative experiments in which we removed the putative ant-attracting appendages (“kapéllos”) from galls and found that ants are specifically attracted to kapéllos. Finally, we compared the chemical composition and histology of ant-attracting appendages on seeds and galls and found that they both have similar fatty acid compositions as well as morphology. We also observed seed-dispersing ants retrieving oak galls to their nests and rodents and birds consuming oak galls that were not retrieved by ants. These results suggest convergence in ant-mediated dispersal between myrmecochorous seeds and oak galls. Based on our observations, a protective advantage for galls retrieved to ant nests seems a more likely benefit than dispersal distance, as has also been suggested for myrmecochorous seeds. These results require reconsideration of established ant-plant research assumptions, as ant-mediated seed and gall dispersal appear strongly convergent and galls may be far more abundant in eastern North American deciduous forests than myrmecochorous seeds.
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This content will become publicly available on November 12, 2026
Taxonomic revision of the Amazonian genus Pseudoernestia (Melastomataceae, Marcetieae)
Pseudoernestia (Melastomataceae: Marcetieae) is a genus comprising two species, P. cordifolia and P. glandulosa, with disjunct distributions along the Amazon Rainforest. The genus is characterized by narrow sepals, petals bearing an apical glandular trichome, antesepalous stamens with aristate ventral appendages and calcarate dorsal appendages positioned opposite the ventral ones, a glabrous ovary with three locules, rarely two, and seeds lacking dorsolateral projections. We present a taxonomic review of Pseudoernestia, including a lectotypification for P. cordifolia, the type species of the genus. Based on herbarium data, we confirmed that P. cordifolia occurs in Venezuela and Brazil, typically on rocky outcrops, whereas P. glandulosa is found in French Guiana and Guyana, primarily on lateritic soils. Pseudoernestia cordifolia is categorized as Endangered, while P. glandulosa is assessed as Least Concern. We provide detailed descriptions, photographs of living specimens, scanning electron microscopy images of the seeds, geographic distribution maps, and notes on conservation status, habitat preferences, and phenology.
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- Award ID(s):
- 2001357
- PAR ID:
- 10648457
- Publisher / Repository:
- Magnolia Press
- Date Published:
- Journal Name:
- Phytotaxa
- Volume:
- 728
- Issue:
- 2
- ISSN:
- 1179-3155
- Page Range / eLocation ID:
- 153-165
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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