Carex richardsonii

R. Brown in J. Franklin et al.

in J. Franklin et al., Narr. Journey Polar Sea, 751. 1823

Common names: Richardson’s sedge carex de Richardson
Treatment appears in FNA Volume 23. Treatment on page 547. Mentioned on page 545, 546, 548.
Click plate for higher resolution version.
Illustrator: Susan A. Reznicek
Plants loosely cespitose, long-rhizomatous. Culms 14–32 cm. Leaves: basal sheaths dark purplish to reddish brown; blades mostly basal, pale green, shorter than culms, thick, 0.9–3.3 mm wide. Inflorescences: peduncles of proximal pistillate spikes to 7 cm; peduncles of terminal staminate spikes 3.3–15.7 mm; proximal bracts long-sheathing; pistillate spikes 2–4, emerging from cauline nodes, widely separated, ascending, ovoid to ellipsoid or short-cylindric; terminal staminate spikes 17.4–23 × 2.5–3.8 mm. Scales: pistillate scales reddish brown, ovate, apex acute to obtuse, glabrous; staminate scales reddish brown, ovate to obovate, margins silvery-white, apex acute to short-acuminate, scarious. Anthers 2.1–2.6 mm. Perigynia obovoid to oblanceoloid, 2.4–2.9 × 1–1.3 mm, base tapering, pubescent with straight white hairs; beak straight, 0.2–0.5 mm. Stigmas 3, flexuous, thin, strongly papillose. Achenes ellipsoid to obovoid, 1.7–1.8 × 1.1–1.2 mm. 2n = 52.

Phenology: Fruiting late spring–summer (late May–mid Jul).
Habitat: Vernally moist (often drying later in the season), open woodlands, alvars, floodplain edges, prairies, and basic and acidic outcrops
Elevation: 50–1400 m


V23 1036-distribution-map.jpg

Alta., B.C., Man., N.W.T., Ont., Que., Sask., Ill., Ind., Iowa, Md., Mich., Minn., N.Y., N.Dak., Ohio, Pa., S.Dak., Vt., Wis., Wyo.


Carex richardsonii is common on the Canadian prairies and in open montane woodlands east of the Cascades. Farther east, it is a rare plant of alvars, tall-grass prairie remnants, and postglacial shorelines, such as those of Lake Iroquois (in Ontario and New York) and Lake Barlow-Ojibway (in Quebec). It is most closely related to, and perhaps the ancestor of, C. concinnoides. Chromosomal data and phylogenetic analysis may help to test that contention.

The long, dark reddish brown sheaths are a conspicuous field mark. Late in the growing season, the leaves often turn dark wine red. This species tends to have low seed set.



Lower Taxa

No lower taxa listed.

Facts about "Carex richardsonii"
AuthorWilliam J. Crins +
AuthorityR. Brown in J. Franklin et al. +
Common nameRichardson’s sedge + and carex de Richardson +
DistributionAlta. +, B.C. +, Man. +, N.W.T. +, Ont. +, Que. +, Sask. +, Ill. +, Ind. +, Iowa +, Md. +, Mich. +, Minn. +, N.Y. +, N.Dak. +, Ohio +, Pa. +, S.Dak. +, Vt. +, Wis. + and Wyo. +
Elevation50–1400 m +
HabitatVernally moist (often drying later in the season), open woodlands, alvars, floodplain edges, prairies, and basic and acidic outcrops +
IllustratorSusan A. Reznicek +
PhenologyFruiting late spring–summer (late May–mid Jul). +
Publication titlein J. Franklin et al., Narr. Journey Polar Sea, +
Publication year1823 +
ReferenceNone +
Source xml grained fna xml/V23/V23 1036.xml +
SynonymsCarex sect. Digitatae +
Taxon familyCyperaceae +
Taxon nameCarex richardsonii +
Taxon parentCarex sect. Clandestinae +
Taxon rankspecies +
VolumeVolume 23 +