Publication details
HOW THISTLE FEMALES WIN? REPRODUCTIVE SUCCESS AND GRANIVORY IN TWO GYNODIOECIOUS CIRSIUM SPECIES
| Authors | |
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| Year of publication | 2025 |
| Type | Conference abstract |
| Citation | |
| Description | Gynodioecy—the coexistence of hermaphrodites and females within a species—poses a classic evolutionary puzzle: why do females persist when hermaphrodites can reproduce in both roles? We addressed this by comparing two gynodioecious thistles with contrasting life histories and female frequencies: Cirsium heterophyllum (polycarpic, high female frequency) and C. palustre (monocarpic, low female frequency). We measured vegetative traits (plant height, stem robustness), reproductive output (number of capitula, achene viability, total and developed achenes), and pre-dispersal achene predation. In both species, females consistently produced more fully developed achenes than hermaphrodites and experienced lower levels of achene predation. The most damaging predators were weevils, whose larvae used the capitula as brood sites and consumed the achenes, accounting for most achene loss in both species. These results suggest that enhanced reproductive success, combined with reduced granivory, underpins the persistence of females in gynodioecious Cirsium, offering fresh insight into the maintenance of plant sexual polymorphisms. |