The genus Carex of Renfrew County:
A comparative study

By Grant A. Bickel, 2020

Carex lucorum Willd. ex Link, Forest Sedge (Section ACROCYSTIS)

Carex lucorum is a ubiquitous species of the Upper Ottawa Valley. It is dominant in red pine plantations and dry sandy woodlands (it is a significant component of my front lawn). It blooms as soon as the soil thaws and warms (Figure 5). It forms large clonal stands and these stands provide opportunities to find variants since the numbers of specimens with variation is amplified by the clonal reproduction. Two such examples from Renfrew County are shown in Figures 8 and 9. The first example is from a large clonal population with androgynous lateral spikes (Figure 8). A more frequent variant is the presence of a second pistillate spike arising from a thin cauline peduncle near the base of the culm (Figure 9). Carex lucorum has often been confused with Carex pensylvanica but the perigynia of Carex lucorum have beaks that are nearly as long or longer than the perigynia body [Crins and Ball, 1983].

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Achenes, perigynia and scales of Carex lucorum

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

Figure 2. Inflorescence.
Habit of Carex lucorum

Figure 3. B&W scan of specimen showing habit.
Field photograph of Carex lucorum

Figure 4. Inflorescences in late April.
Field photograph of Carex lucorum

Figure 5. Inflorescences blooming in late April.
Field photograph of Carex lucorum

Figure 6. Inflorescences blooming in May.
Field photograph of Carex lucorum

Figure 7. Inflorescences matured late May.
Inflorescence of androgynous form of Carex lucorum

Figure 8. Form with androgynous lateral spikes.
Habit of Carex lucorum form with cauline pistillate spike

Figure 9. B&W scan of form with cauline pistillate spike.
Habitat of Carex lucorum

Figure 10. Habitat in late summer.
An occurrence map of Carex lucorum in Renfrew County

Figure 11. Occurence map for Renfrew County and surrounding area.
Accession records for specimens from Renfrew County
Accession # Collector Date
DAO 671421 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671422 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671423 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671424 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671429 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671430 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671431 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 671432 P.M. Catling & S.E. Carbyn 1994-June-01
DAO 669066 P.M. Catling & S.E. Carbyn 1993-September-22
DAO 668432 S.E. Carbyn 1993-July-07
DAO 668433 S.E. Carbyn 1993-July-07
DAO 668437 P.M. Catling & S.E. Carbyn 1993-June-17
DAO 668438 P.M. Catling & S.E. Carbyn 1993-June-17
DAO 671403 P.M. Catling & S.E. Carbyn 1993-June-17
DAO 671410 P.M. Catling & S.E. Carbyn 1993-June-17
DAO 671414 P.M. Catling & S.E. Carbyn 1993-June-17
DAO 573880 K.W. Spicer 1988-July-14
CAN 520284, DAO 486717 S.J. Darbyshire 1985-July-07
CAN 494482 M.D. Kirk 1982-May-15
CAN 457069 S. Darbyshire 1981-May-31
DAO 659210 M.I. Moore 1969-June-16
CAN 569995 M.I. Moore 1968-June-05
CAN 569997 M. Moore 1966-July-20
DAO 200080 M.I. Moore 1964-June-12
CAN 570000 T.C. Brayshaw 1962-June-09
CAN 569998 T.C. Brayshaw 1960-June-08
CAN 262155 J.S. Rowe 1958-June-13
DAO 200164 A.J. Breitung 1948-July-26
CAN 570001 H.H. McKay 1921-July

References

Crins, W.J. and Ball, P.W., The Taxonomy of Carex pensylvanica complex (Cyperaceae) in North America, Can. J. Bot., Vol. 61, pp. 1692-1717, 1983.