The genus Carex of Renfrew County:
A comparative study

By Grant A. Bickel, 2025

Carex pensylvanica Lam., Pennsylvania Sedge (Section ACROCYSTIS)

Carex pensylvanica is sparse in Renfrew County. It seems to avoid the sandy soils of the northwestern portion of the county. Specimens of Carex pensylvanica are frequently found enveloped in a black powdery fungus and that may be one reason why there are so few collections in Renfrew County. Interestingly, the closely similar Carex lucorum is only rarely found to be host of this fungus in Renfrew County - perhaps a result of its soil preference.

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Achenes, perigynia and scales of Carex pensylvanica

Figure 1. Achenes, perigynia and scales.
Inflorescence of Carex pensylvanica

Figure 2. Inflorescence.
Inflorescence of Carex pensylvanica

Figure 3. Inflorescences.
Habit of Carex pensylvanica

Figure 4. Habit in summer.
An occurrence map of Carex pensylvanica in Renfrew County

Figure 5. Occurence map for Renfrew County and surrounding area.
Accession records for specimens from Renfrew County
Accession # Collector Date
DAO 662814 K.W. Spicer 1989-June-07
DAO 573992 K.W. Spicer 1988-June-15
DAO 200063 J.A. Calder 1948-May-30