Section VESICARIAE
Section VESICARIAE is represented by nine species in Renfrew County. These are all wetland species.
Seven of the species in this section are also known as the 'bladder' sedges, so called because of their inflated thin-walled perigynia loosely enclosing the achenes (Figure 1).
- Carex hystericina
- Carex lurida
- Carex oligosperma
- Carex tuckermanii
- Carex retrorsa
- Carex vesicaria
- Carex utriculata
The remaining two species, Carex comosa and Carex pseudocyperus have thick-walled perigynia tightly enclosing the achene. Carex comosa and Carex pseudocyperus are superficially very similar looking (Figure 2) and occupy common habitats. However, this species pair is easy to separate. The pistillate spikes of Carex pseudocyperus have perigynia lined up in ranks, are retrorse to the axis of the spike and the spike is narrower and longer overall when compared to Carex comosa (Figure 2). The most obvious difference is the beaks of the perigynia which are straight for Carex pseudocyperus and arching outwards for Carex comosa (Figure 3).
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Figure 1. Comparison of perigynia of the 'bladder' sedges (all to same scale).
Figure 2. Comparison of inflorescences.
Figure 3. Comparison of perigynia. Notice that apart from the beak, the morphology of the perigynia are identical.