Carex Search

Note: this key assumes mature plants, with mature perigynia. It is best to use the “average” characteristics from a population, rather than using only those characteristics from a single plant. For example, some plants in a population may have multiple staminate spikes but your particular specimen has only one.

When in doubt, leave the setting to “any” and only set those characteristics you can say with some confidence are true or false. Good luck. :-)

Plant Description

Examples of plant characteristics

CharacteristicTrueFalseAny
clump forming
colony forming
stem, leaves or sheaths distinctly hairy (not just rough)
base red or purple
base fibrous
stems all or mostly longer than the leaves
Spike Description

Examples of spike characteristics

CharacteristicTrueFalseAny
spikes on a stem all alike
spikes on a stem all staminate or all pistillate
1 or more lateral spikes stalked
pistillate spikes drooping
spikes all crowded at the tip of the stem
terminal spike all staminate
1 or more spikes staminate at the base, pistillate at the tip
1 or more spikes pistillate at the base, staminate at the tip
more than 1 spike all staminate
Perigynia Description

Examples of perigynia, scale and achene characteristics

CharacteristicTrueFalseAny
perigynia surface hairy (not just the edges)
perigynia winged
perigynia distinctly beaked
perigynia beak visibly toothed
perigynia at least partly spongy or inflated
perigynia veinless or at most 2 veins/ribs
perigynia max length 3mm or less
perigynia max length more than 5mm
some or all scales (including any awn) about as long as or longer than the perigynia
some or all scales awned
achene flattened lens-shaped, 2 stigmas
styles on achenes persistent
Miscellaneous

* Note: some counties are underreported so a species may be present but not yet recorded there.