OregonFlora: Carex longii vs. Carex aquatilis

	Carex longii	Carex aquatilis
	green-and-white sedge	water sedge
Habit	Plants cespitose, 30–120 cm tall, the vegetative culms sometimes rooting at nodes.	Plants rhizomatous with deep rhizomes; sometimes forming large stands; culms 20–150 cm tall; plant bases reddish brown, chestnut, or brown.
Leaves	sheath fronts green and veined except for a small white-hyaline triangle at the top; blades 2–4.5 mm wide.	sheath fronts not ladder-fibrillose; blades 2.5–18 mm wide, green or glaucous.
Inflorescences	1–4.5(6) cm × 5–14 mm, typically elongate; spikes distinct but overlapping, gynaecandrous, rounded or tapered to tip.	lateral 2–6 spikes female or androgynous; erect or drooping, 1–112 cm × 3–18 mm, bases blunt or tapering; terminal 1–4 spikes male.
Perigynia	obovate, 3–4.6 × 1.6–2.6(2.8) mm; the body widest above the middle, green or light brown; veins 5 to many on each face; wings 0.5–0.8 mm wide; beak tip winged and ciliate-serrulate almost to the tip, 1.4–2.2 mm from achene top to beak tip; stigmas 2.	elliptic to obovate, 1.9–3.6 × 1–2.3 mm, green; tawny, or pale brown with reddish; purplish, or brownish spots; veinless or nearly so, with rounded “shoulders”; beak to 0.4 mm, not bidentate; stigmas 2.
Achenes	lenticular, 1.3–1.7 × 0.7–1 mm, 0.4–0.5 mm thick.	lenticular, 1.1–1.8 × 0.7–1.5 mm.
Female scales	2.2–3.7 mm long; shorter and narrower than the perigynia, white-hyaline; aging silvery brown, with green center; apex obtuse.	longer than the perigynia; reddish brown or black.
2n	=58, 60, 62.

	Carex longii	Carex aquatilis
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Bogs and pond shores, on peaty or sandy soils, often where water levels fluctuate greatly, sometimes a weed in cranberry bogs. 0–50 m. Est. WA; eastern North America, HI, Central America, Caribbean; New Zealand. Exotic. Carex longii is cespitose and has a silvery-green, elongated inflorescences and green leaf sheath fronts. It strongly resembles native C. feta, which has rounder spikes and perigynium bodies widest near the middle.	Carex aquatilis is a strongly rhizomatous sedge with two stigmas per perigynium and lenticular achenes. It is distinguished from similar species by its reddish or red-brown plant bases. Many C. aquatilis populations, especially in the Cascades, have plants with morphology intermediate between that of the varieties, or even resembling both extremes; these should be reported as C. aquatilis, not either variety.
Source	Flora of Oregon, volume 1, page 212 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. 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. 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. 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. 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
Subordinate taxa		C. aquatilis var. aquatilis, C. aquatilis var. dives
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 aquatilis

green-and-white sedge

water sedge

Habit

Plants cespitose, 30–120 cm tall, the vegetative culms sometimes rooting at nodes.

Plants rhizomatous with deep rhizomes; sometimes forming large stands; culms 20–150 cm tall; plant bases reddish brown, chestnut, or brown.

Leaves

sheath fronts green and veined except for a small white-hyaline triangle at the top;

blades 2–4.5 mm wide.

sheath fronts not ladder-fibrillose;

blades 2.5–18 mm wide, green or glaucous.

Inflorescences

1–4.5(6) cm × 5–14 mm, typically elongate;

spikes distinct but overlapping, gynaecandrous, rounded or tapered to tip.

lateral 2–6 spikes female or androgynous; erect or drooping, 1–112 cm × 3–18 mm, bases blunt or tapering; terminal 1–4 spikes male.

Perigynia

obovate, 3–4.6 × 1.6–2.6(2.8) mm; the body widest above the middle, green or light brown;

veins 5 to many on each face;

wings 0.5–0.8 mm wide;

beak tip winged and ciliate-serrulate almost to the tip, 1.4–2.2 mm from achene top to beak tip;

stigmas 2.

elliptic to obovate, 1.9–3.6 × 1–2.3 mm, green; tawny, or pale brown with reddish; purplish, or brownish spots; veinless or nearly so, with rounded “shoulders”;

beak to 0.4 mm, not bidentate;

stigmas 2.

Achenes

lenticular, 1.3–1.7 × 0.7–1 mm, 0.4–0.5 mm thick.

lenticular, 1.1–1.8 × 0.7–1.5 mm.

Female scales

2.2–3.7 mm long; shorter and narrower than the perigynia, white-hyaline; aging silvery brown, with green center;

apex obtuse.

longer than the perigynia; reddish brown or black.

=58, 60, 62.

Carex aquatilis

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Bogs and pond shores, on peaty or sandy soils, often where water levels fluctuate greatly, sometimes a weed in cranberry bogs. 0–50 m. Est. WA; eastern North America, HI, Central America, Caribbean; New Zealand. Exotic.

Carex longii is cespitose and has a silvery-green, elongated inflorescences and green leaf sheath fronts. It strongly resembles native C. feta, which has rounder spikes and perigynium bodies widest near the middle.

Carex aquatilis is a strongly rhizomatous sedge with two stigmas per perigynium and lenticular achenes. It is distinguished from similar species by its reddish or red-brown plant bases. Many C. aquatilis populations, especially in the Cascades, have plants with morphology intermediate between that of the varieties, or even resembling both extremes; these should be reported as C. aquatilis, not either variety.

Source

Flora of Oregon, volume 1, page 212
Barbara Wilson, Richard Brainerd, Nick Otting

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

Sibling taxa