OregonFlora: Carex echinata vs. Carex obnupta

	Carex echinata	Carex obnupta
	prickly sedge, star sedge	slough sedge
Habit	Plants cespitose, 10–90(135) cm tall.	Plants rhizomatous but deep rhizomes often not collected; culms 20–120(200) cm tall; plant bases reddish brown or blackish.
Leaves	usually 0.7–3(3.8) mm wide.	sheath fronts coppery, densely red-dotted; ladder-fibrillose; blades 3–7 mm wide; evergreen; tough, green when young; aging yellowish green with sharp; antrorse marginal prickles; leaf sheath fronts coppery, densely red-dotted; ladder-fibrillose.
Inflorescences	spikes separated or crowded, usually gynaecandrous, with perigynia widely spreading or reflexed at maturity; lateral spikes 3–15.5 mm long; terminal spikes 5–24 mm long, often with a narrow male portion 2–16.5 mm long.	lowest inflorescence bract longer than the inflorescence; lateral 2–5 spikes female, dark brown; erect to drooping, tapering at base, 2.5–15 cm × 4.5–10 mm; upper 2–3(5) spikes male.
Perigynia	tapered gradually to the beak; (2.6)3–4.8 mm long, green to brown, veined or veinless on the ventral surface over the achene; base swollen; pithy when mature; beak 0.9–2 mm long, 33–60% of perigynium length.	2.2–3.8 × 1.4–2.2 mm, dark brown; hard; veinless; beak 0.1–0.3 mm; stigmas 2.
Achenes	lenticular.	lenticular, often indented on one or both sides.
Female scales	inconspicuous; shorter than the mature achene.	longer than the perigynia; reddish brown; acute; awnless.
2n		=70, 72, 74, 76.

	Carex echinata	Carex obnupta
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Cosmopolitan. 2 subspecies. Narrow-leaved Carex echinata is identified by its widely spreading, gradually tapering perigynia in star-like spikes.	Marshes, wet meadows, streamsides, pond margins, low spots in riparian woodlands—often with Fraxinus latifolia (Oregon ash), stabilized coastal dunes, brackish upper reaches of salt marshes and road ditches. 0–1300 m. Casc, CR, Est, Sisk, WV. CA, WA; north to British Columbia. Native. Only this species and C. lyngbyei have such hard perigynia. Carex lyngbyei grows in salt marshes and has smooth-edged leaves that die in winter, yellow-brown perigynia, and straight, usually truncate-based spikes on arching peduncles. Carex aquatilis var. dives has softer leaves and perigynia, and leaf sheath fronts that lack coppery color and are not ladder-fibrillose. Carex barbarae of southwestern Oregon has brown, usually erect spikes and scabrous awns at the tips of the female scales. Presumed hybrids with C. aquatilis var. dives and C. barbarae have been collected in Oregon. Carex obnupta holds its perigynia through the winter, releasing them on spring floods.
Source	Flora of Oregon, volume 1, page 199 Barbara Wilson, Richard Brainerd, Nick Otting	Flora of Oregon, volume 1, page 217 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. 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. 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. 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. 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. 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
Subordinate taxa	C. echinata ssp. echinata, C. echinata ssp. phyllomanica
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, 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 obnupta

prickly sedge, star sedge

slough sedge

Habit

Plants cespitose, 10–90(135) cm tall.

Plants rhizomatous but deep rhizomes often not collected; culms 20–120(200) cm tall; plant bases reddish brown or blackish.

Leaves

usually 0.7–3(3.8) mm wide.

sheath fronts coppery, densely red-dotted; ladder-fibrillose;

blades 3–7 mm wide; evergreen; tough, green when young; aging yellowish green with sharp; antrorse marginal prickles; leaf sheath fronts coppery, densely red-dotted; ladder-fibrillose.

Inflorescences

spikes separated or crowded, usually gynaecandrous, with perigynia widely spreading or reflexed at maturity;

lateral spikes 3–15.5 mm long; terminal spikes 5–24 mm long, often with a narrow male portion 2–16.5 mm long.

lowest inflorescence bract longer than the inflorescence;

lateral 2–5 spikes female, dark brown; erect to drooping, tapering at base, 2.5–15 cm × 4.5–10 mm; upper 2–3(5) spikes male.

Perigynia

tapered gradually to the beak; (2.6)3–4.8 mm long, green to brown, veined or veinless on the ventral surface over the achene;

base swollen; pithy when mature;

beak 0.9–2 mm long, 33–60% of perigynium length.

2.2–3.8 × 1.4–2.2 mm, dark brown; hard; veinless;

beak 0.1–0.3 mm;

stigmas 2.

Achenes

lenticular.

lenticular, often indented on one or both sides.

Female scales

inconspicuous; shorter than the mature achene.

longer than the perigynia; reddish brown; acute; awnless.

=70, 72, 74, 76.

Carex obnupta

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Cosmopolitan. 2 subspecies.

Narrow-leaved Carex echinata is identified by its widely spreading, gradually tapering perigynia in star-like spikes.

Marshes, wet meadows, streamsides, pond margins, low spots in riparian woodlands—often with Fraxinus latifolia (Oregon ash), stabilized coastal dunes, brackish upper reaches of salt marshes and road ditches. 0–1300 m. Casc, CR, Est, Sisk, WV. CA, WA; north to British Columbia. Native.

Only this species and C. lyngbyei have such hard perigynia. Carex lyngbyei grows in salt marshes and has smooth-edged leaves that die in winter, yellow-brown perigynia, and straight, usually truncate-based spikes on arching peduncles. Carex aquatilis var. dives has softer leaves and perigynia, and leaf sheath fronts that lack coppery color and are not ladder-fibrillose. Carex barbarae of southwestern Oregon has brown, usually erect spikes and scabrous awns at the tips of the female scales. Presumed hybrids with C. aquatilis var. dives and C. barbarae have been collected in Oregon. Carex obnupta holds its perigynia through the winter, releasing them on spring floods.