The genus Cyperus of Renfrew County:
A comparative study

By Grant A. Bickel, 2020

Cyperus odoratus Linnaeus, Rusty flatsedge

Cyperus odoratus is rare in Renfrew County. All records and my personal observations are best ascribed morphologically to Cyperus engelmannii but is lumped under Cyperus odoratus in Flora of North America (http://floranorthamerica.org/). These specimens are found on sandbars and exposed riverbeds. Populations can be quite dense but very localized.

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Spikelets and achenes of Cyperus odoratus

Figure 1. Spikelets and achenes.
Inflorescence of Cyperus odoratus

Figure 2. Inforescence.
Cyperus odoratus in nature

Figure 3. Habit.
Cyperus odoratus in nature

Figure 4. Habit.
Cyperus odoratus in nature

Figure 5. Habit.
Cyperus odoratus in nature

Figure 6. Habit.
An occurrence map of Cyperus odoratus in Renfrew County

Figure 7. Occurence map for Renfrew County and surrounding area.
Accession records for specimens from Renfrew County
Accession # Collector Date
DAO 598090 J. Atkinson & R. Huizer 1991-August-15
DAO 593408 D.F. Brunton 1987-August-26
CAN 570144, DAO 623619 M.I. Moore & J.S. Johnston 1971-September-06