OregonFlora: Carex concinna vs. Carex arenaria

	Carex concinna	Carex arenaria
	cute sedge	sand sedge
Habit	Plants rhizomatous, shoots arising singly or in clumps, 5.5–20 cm tall; plant bases reddish brown.	Plants rhizomatous, forming large populations, the rhizomes with a thick pithy cortex; culms 15–60 cm tall, erect.
Leaves	sheath fronts membranous; blades 1–3.1 mm wide.	sheath fronts at top yellowish, thickened; concave; blades 1.5–4 mm wide.
Inflorescences	basal spikes absent; lowest bract sheath inflated, 2–5 mm long; blade absent or less than 2 cm long, purpletinged; lateral spikes 2–3, crowded near the terminal spike, 0.4–0.7 × 0.2–0.4 mm; terminal spike male; tiny, 0.3–0.7 cm × 1.1–1.5 mm.	2–8 cm long; somewhat shaggy looking; spikes 5–15, overlapping, ascending, androgynous or female, or the uppermost male.
Perigynia	elliptic, 2.3–3.3(3.5) × 1.1–1.4 mm, pubescent with crinkled hairs; veinless but with 2 ribs, bases succulent, withering when dry; beak 0.3–0.4 mm long; stigmas 3.	lanceolate to broadly ovate; plano-convex; (4)4.5–6 × 1.3–3.3 mm, light brown; several-veined, broadly winged above the middle; beak 1.2–2.5 mm long; stigmas 2.
Achenes	rounded to trigonous.	lenticular.
Male scales	dark reddish brown with whitish margins.
Female scales	smaller than the perigynia; reddish brown; ovate; apex obtuse, minutely ciliate.	usually longer than the perigynia; reddish brown with green midrib and hyaline margins.
Anthers	1.3–1.4 mm long.
2n	=54.

	Carex concinna	Carex arenaria
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Stream banks, bogs, meadows, and open forests, on stable, usually calcareous substrates that are wet in spring but may dry out later. 1600–2500 m. BW. North to AK, east to Newfoundland. Native. Carex concinna is recognized by its hairy perigynia, tiny staminate spike, and absent or tiny inflorescence bract. It lacks basal spikes among the leaf bases.	In Europe, where it is native, habitat is mainly moving sands near the coast but also inland sandy soils, usually in full sun but persisting in shade, e.g., in pine forests. 0–50 m. WV. DE to NC; Australia, Eurasia. Exotic. Carex arenaria is strongly rhizomatous, with shaggy inflorescences and large, partly winged perigynia. It was introduced in Portland by 1916, probably in ships’ ballast, and rediscovered on Sauvie Island in 2003.
Source	Flora of Oregon, volume 1, page 195 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 189 Barbara Wilson, Richard Brainerd, Nick Otting
Sibling taxa	C. abrupta, C. agastachys, C. amplifolia, C. angustata, C. aperta, C. aquatilis, C. arcta, C. arenaria, C. atherodes, C. athrostachya, C. atrosquama, C. aurea, C. barbarae, C. bebbii, C. bolanderi, C. brainerdii, C. brevior, C. breweri, C. buchananii, C. buxbaumii, C. californica, C. canescens, C. capillaris, C. capitata, C. chordorrhiza, C. comans, C. comosa, C. concinnoides, C. cordillerana, C. crawfordii, C. cusickii, C. davyi, C. deflexa, C. densa, C. diandra, C. disperma, C. distans, C. douglasii, C. duriuscula, C. echinata, C. exsiccata, C. feta, C. filifolia, C. fissuricola, C. fracta, C. geyeri, C. gynocrates, C. gynodynama, C. halliana, C. harfordii, C. hassei, C. haydeniana, C. hendersonii, C. heteroneura, C. hirsutella, C. hirta, C. hoodii, C. hystericina, C. idahoa, C. illota, C. infirminervia, C. inops, C. integra, C. interior, C. interrupta, C. jonesii, C. kelloggii, C. klamathensis, C. kobomugi, C. laeviculmis, C. lasiocarpa, C. leporina, C. leporinella, C. leptalea, C. leptopoda, C. limosa, C. livida, C. longii, C. luzulina, C. lyngbyei, C. macrocephala, C. macrochaeta, C. media, C. mendocinensis, C. mertensii, C. mesochorea, C. micropoda, C. microptera, C. multicaulis, C. nardina, C. nebrascensis, C. nervina, C. neurophora, C. nigricans, C. nudata, C. obnupta, C. pachycarpa, C. pachystachya, C. pansa, C. paysonis, C. pellita, C. pelocarpa, C. pendula, C. petasata, C. phaeocephala, C. pluriflora, C. praeceptorum, C. praegracilis, C. praticola, C. preslii, C. pumila, C. raynoldsii, C. retrorsa, C. rossii, C. saxatilis, C. scabriuscula, C. scirpoidea, C. scoparia, C. scopulorum, C. serpenticola, C. serratodens, C. sheldonii, C. simulata, C. spectabilis, C. stipata, C. straminiformis, C. subbracteata, C. subfusca, C. subnigricans, C. sychnocephala, C. tahoensis, C. tiogana, C. tribuloides, C. tumulicola, C. unilateralis, C. utriculata, C. vallicola, C. vernacula, C. vesicaria, C. viridula, C. vulpinoidea, C. whitneyi, C. zikae	C. abrupta, C. agastachys, C. amplifolia, C. angustata, C. aperta, C. aquatilis, C. arcta, C. atherodes, C. athrostachya, C. atrosquama, C. aurea, C. barbarae, C. bebbii, C. bolanderi, C. brainerdii, C. brevior, C. breweri, C. buchananii, C. buxbaumii, C. californica, C. canescens, C. capillaris, C. capitata, C. chordorrhiza, C. comans, C. comosa, C. concinna, C. concinnoides, C. cordillerana, C. crawfordii, C. cusickii, C. davyi, C. deflexa, C. densa, C. diandra, C. disperma, C. distans, C. douglasii, C. duriuscula, C. echinata, C. exsiccata, C. feta, C. filifolia, C. fissuricola, C. fracta, C. geyeri, C. gynocrates, C. gynodynama, C. halliana, C. harfordii, C. hassei, C. haydeniana, C. hendersonii, C. heteroneura, C. hirsutella, C. hirta, C. hoodii, C. hystericina, C. idahoa, C. illota, C. infirminervia, C. inops, C. integra, C. interior, C. interrupta, C. jonesii, C. kelloggii, C. klamathensis, C. kobomugi, C. laeviculmis, C. lasiocarpa, C. leporina, C. leporinella, C. leptalea, C. leptopoda, C. limosa, C. livida, C. longii, C. luzulina, C. lyngbyei, C. macrocephala, C. macrochaeta, C. media, C. mendocinensis, C. mertensii, C. mesochorea, C. micropoda, C. microptera, C. multicaulis, C. nardina, C. nebrascensis, C. nervina, C. neurophora, C. nigricans, C. nudata, C. obnupta, C. pachycarpa, C. pachystachya, C. pansa, C. paysonis, C. pellita, C. pelocarpa, C. pendula, C. petasata, C. phaeocephala, C. pluriflora, C. praeceptorum, C. praegracilis, C. praticola, C. preslii, C. pumila, C. raynoldsii, C. retrorsa, C. rossii, C. saxatilis, C. scabriuscula, C. scirpoidea, C. scoparia, C. scopulorum, C. serpenticola, C. serratodens, C. sheldonii, C. simulata, C. spectabilis, C. stipata, C. straminiformis, C. subbracteata, C. subfusca, C. subnigricans, C. sychnocephala, C. tahoensis, C. tiogana, C. tribuloides, C. tumulicola, C. unilateralis, C. utriculata, C. vallicola, C. vernacula, C. vesicaria, C. viridula, C. vulpinoidea, C. whitneyi, C. zikae
Web links	Local floras: BC, OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Carex arenaria

cute sedge

sand sedge

Habit

Plants rhizomatous, shoots arising singly or in clumps, 5.5–20 cm tall; plant bases reddish brown.

Plants rhizomatous, forming large populations, the rhizomes with a thick pithy cortex; culms 15–60 cm tall, erect.

Leaves

sheath fronts membranous;

blades 1–3.1 mm wide.

sheath fronts at top yellowish, thickened; concave;

blades 1.5–4 mm wide.

Inflorescences

basal spikes absent; lowest bract sheath inflated, 2–5 mm long;

blade absent or less than 2 cm long, purpletinged;

lateral spikes 2–3, crowded near the terminal spike, 0.4–0.7 × 0.2–0.4 mm; terminal spike male; tiny, 0.3–0.7 cm × 1.1–1.5 mm.

2–8 cm long; somewhat shaggy looking;

spikes 5–15, overlapping, ascending, androgynous or female, or the uppermost male.

Perigynia

elliptic, 2.3–3.3(3.5) × 1.1–1.4 mm, pubescent with crinkled hairs; veinless but with 2 ribs, bases succulent, withering when dry;

beak 0.3–0.4 mm long;

stigmas 3.

lanceolate to broadly ovate; plano-convex; (4)4.5–6 × 1.3–3.3 mm, light brown; several-veined, broadly winged above the middle;

beak 1.2–2.5 mm long;

stigmas 2.

Achenes

rounded to trigonous.

lenticular.

Male scales

dark reddish brown with whitish margins.

Female scales

smaller than the perigynia; reddish brown; ovate;

apex obtuse, minutely ciliate.

usually longer than the perigynia; reddish brown with green midrib and hyaline margins.

Anthers

1.3–1.4 mm long.

=54.

Carex arenaria

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Stream banks, bogs, meadows, and open forests, on stable, usually calcareous substrates that are wet in spring but may dry out later. 1600–2500 m. BW. North to AK, east to Newfoundland. Native.

Carex concinna is recognized by its hairy perigynia, tiny staminate spike, and absent or tiny inflorescence bract. It lacks basal spikes among the leaf bases.

In Europe, where it is native, habitat is mainly moving sands near the coast but also inland sandy soils, usually in full sun but persisting in shade, e.g., in pine forests. 0–50 m. WV. DE to NC; Australia, Eurasia. Exotic.

Carex arenaria is strongly rhizomatous, with shaggy inflorescences and large, partly winged perigynia. It was introduced in Portland by 1916, probably in ships’ ballast, and rediscovered on Sauvie Island in 2003.

Source

Flora of Oregon, volume 1, page 195
Barbara Wilson, Richard Brainerd, Nick Otting

Flora of Oregon, volume 1, page 189
Barbara Wilson, Richard Brainerd, Nick Otting

Sibling taxa