The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

weak stellate sedge

Columbia sedge, Columbian sedge, open sedge

Habit Plants not cespitose.
Culms

15–75 cm.

acutely angled, 15–90 cm, scabrous.

Leaves

2–4 per culm;

sheaths with inner band hyaline, 3.5–12 cm, apex deeply concave, glabrous;

ligules 1.7–7 mm, apex acute or often emarginate;

blades plicate to flat, 9–50 cm × 0.8–3.9 mm, widest leaf 2.1–3.9 mm wide.

basal sheaths red-brown;

sheaths of proximal leaves with blades, backs glabrous, fronts with pale brown spots, veinless, glabrous, apex U-shaped, membranous, colorless;

blades 3–6 mm wide.

Inflorescences

1.8–7 cm;

spikes 4–8;

lateral spikes pistillate often with few staminate flowers proximally, 2.8–10.8 mm, sessile, staminate portion (0–)1–6-flowered, (0–)0.8–4.6 mm, pistillate portion 4–25-flowered, 2–7.6 mm;

basal 2 spikes 5–27 mm apart;

terminal spike gynecadrous, 4.7–16.5 mm, staminate portion 3–13-flowered, 1.8–12.7 × 0.9–2.1 mm, pistillate portion 6–23-flowered, 2.8–7.3 × 4.4–6 mm.

proximal bract subequal to inflorescence, 2–4 mm wide.

Spikes

erect;

proximal 2–3 spikes pistillate, 1.5–3.5 cm × 4–6 mm, base obtuse;

terminal 1–2 spikes staminate.

Perigynia

spreading to reflexed, green, 6–14-veined abaxially, 0–6-veined adaxially over achene, elliptic to elliptic-ovate, 1.8–2.9 × 1–1.9 mm, 1.2–2.1 times as long as wide;

beak 0.2–0.6 mm, 0.09–0.33 length of body, smooth.

divergent, olive-brown with red-brown spots on apical 1/2, veinless, inflated, loosely enclosing achenes, obovoid, 2.5–2.8 × 1.5–2 mm, dull, apex rounded, papillose;

beak green, 0.1–0.3 mm.

Achenes

ovate to orbiculate, 1.2–1.6 × 0.85–1.4 mm.

not constricted, dull.

Pistillate

scales ovate, 1.2–2.2 × 1–1.6 mm, apex acute.

scales red-brown, longer than perigynia, apex acute or acuminate, awnless.

Staminate

scales ovate, 1.7–3.3 × 1–1.4 mm, apex acute.

Anthers

1–1.9 mm.

2n

= 54.

Carex seorsa

Carex aperta

Phenology Fruiting late spring–early summer. Fruiting Jul–Aug.
Habitat Acidic, sandy, peaty hardwood or Chamaecyparis swamps, thickets Wet meadows
Elevation 0–300 m (0–1000 ft) 0–900 m (0–3000 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IN; KY; MA; MD; MI; MS; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
ID; MT; OR; WA; AB; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Carex seorsa very rarely hybridizes with C. atlantica subsp. atlantica.

Carex seorsa is unusual in sect. Stellulatae in its primarily forest understory habitat, lax, spreading habit, perigynia widest in the middle, and smooth perigynia beaks. Its affinities require further study.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Carex aperta and C. haydenii appear to be a very closely related, allopatric pair of species that may not be closely related to other members of the section. This species-pair is distinguished by the inflated perigynia, the acute scales that are longer than the perigynia, and the unique chromosome number. Carex aperta is distinguished from C. haydenii by its rhizomatous habit, the dull brown achenes, and the entire beak. It is sometimes mistaken for the sympatric taxa that also lack veins on the perigynia, C. aquatilis and C. scopulorum; mature specimens can easily be identified by the inflated perigynia.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 331. FNA vol. 23, p. 395.
Parent taxa Cyperaceae > Carex > sect. Stellulatae Cyperaceae > Carex > sect. Phacocystis
Sibling taxa
C. aboriginum, C. abrupta, C. abscondita, C. acidicola, C. acutiformis, C. adelostoma, C. adusta, C. aestivalis, C. aggregata, C. alata, C. albicans, C. albida, C. albolutescens, C. albonigra, C. albursina, C. alma, C. alopecoidea, C. amphibola, C. amplectens, C. amplifolia, C. angustata, C. annectens, C. anthoxanthea, C. aperta, C. appalachica, C. aquatilis, C. arapahoensis, C. arcta, C. arctata, C. arctiformis, C. arenaria, C. argyrantha, C. arkansana, C. assiniboinensis, C. atherodes, C. athrostachya, C. atlantica, C. atrata, C. atratiformis, C. atrofusca, C. atrosquama, C. aurea, C. aureolensis, C. austrina, C. austrocaroliniana, C. backii, C. baileyi, C. baltzellii, C. barbarae, C. barrattii, C. basiantha, C. bebbii, C. bella, C. bicknellii, C. bicolor, C. bigelowii, C. biltmoreana, C. blanda, C. bolanderi, C. bonanzensis, C. brainerdii, C. brevicaulis, C. brevior, C. breweri, C. bromoides, C. brunnescens, C. brysonii, C. bulbostylis, C. bullata, C. bushii, C. buxbaumii, C. calcifugens, C. californica, C. canescens, C. capillaris, C. capitata, C. careyana, C. caroliniana, C. caryophyllea, C. castanea, C. cephaloidea, C. cephalophora, C. chalciolepis, C. chapmanii, C. cherokeensis, C. chihuahuensis, C. chordorrhiza, C. circinata, C. collinsii, C. communis, C. comosa, C. complanata, C. concinna, C. concinnoides, C. congdonii, C. conjuncta, C. conoidea, C. constanceana, C. cordillerana, C. corrugata, C. crawei, C. crawfordii, C. crebriflora, C. crinita, C. cristatella, C. crus-corvi, C. cryptolepis, C. cumberlandensis, C. cumulata, C. curatorum, C. cusickii, C. dasycarpa, C. davisii, C. davyi, C. debilis, C. decomposita, C. deflexa, C. densa, C. deweyana, C. diandra, C. digitalis, C. diluta, C. disperma, C. distans, C. disticha, C. divisa, C. divulsa, C. douglasii, C. duriuscula, C. ebenea, C. eburnea, C. echinata, C. edwardsiana, C. egglestonii, C. eleusinoides, C. elliottii, C. elynoides, C. emoryi, C. endlichii, C. engelmannii, C. epapillosa, C. exilis, C. exsiccata, C. extensa, C. festucacea, C. feta, C. filifolia, C. fissa, C. fissuricola, C. flacca, C. flaccosperma, C. flava, C. floridana, C. foenea, C. folliculata, C. formosa, C. fracta, C. frankii, C. fuliginosa, C. garberi, C. geophila, C. geyeri, C. gholsonii, C. gigantea, C. glacialis, C. glareosa, C. glaucescens, C. glaucodea, C. globosa, C. gmelinii, C. godfreyi, C. gracilescens, C. gracilior, C. gracillima, C. granularis, C. gravida, C. grayi, C. grisea, C. gynandra, C. gynocrates, C. gynodynama, C. halliana, C. hallii, C. harfordii, C. hassei, C. haydeniana, C. haydenii, C. heleonastes, C. helleri, C. hendersonii, C. heteroneura, C. heterostachya, C. hirsutella, C. hirta, C. hirtifolia, C. hirtissima, C. hitchcockiana, C. holostoma, C. hoodii, C. hookeriana, C. hormathodes, C. hostiana, C. houghtoniana, C. hyalina, C. hyalinolepis, C. hystericina, C. idahoa, C. illota, C. impressinervia, C. incurviformis, C. infirminervia, C. inops, C. integra, C. interior, C. interrupta, C. intumescens, C. jamesii, C. jonesii, C. joorii, C. juniperorum, C. kobomugi, C. kraliana, C. krausei, C. lachenalii, C. lacustris, C. laeviconica, C. laeviculmis, C. laevivaginata, C. lapponica, C. lasiocarpa, C. latebracteata, C. lativena, C. laxa, C. laxiculmis, C. laxiflora, C. leavenworthii, C. lemmonii, C. lenticularis, C. leporinella, C. leptalea, C. leptonervia, C. leptopoda, C. limosa, C. livida, C. loliacea, C. lonchocarpa, C. longii, C. louisianica, C. lucorum, C. lupuliformis, C. lupulina, C. lurida, C. lutea, C. luzulifolia, C. luzulina, C. lyngbyei, C. mackenziei, C. macloviana, C. macrocephala, C. macrochaeta, C. magellanica, C. manhartii, C. marina, C. mariposana, C. maritima, C. mckittrickensis, C. meadii, C. media, C. melanostachya, C. membranacea, C. mendocinensis, C. merritt-fernaldii, C. mertensii, C. mesochorea, C. michauxiana, C. microchaeta, C. microdonta, C. microglochin, C. micropoda, C. microptera, C. misera, C. missouriensis, C. mitchelliana, C. molesta, C. molestiformis, C. muehlenbergii, C. multicaulis, C. multicostata, C. muricata, C. muriculata, C. muskingumensis, C. nardina, C. nebrascensis, C. nelsonii, C. nervina, C. neurophora, C. nigra, C. nigricans, C. nigromarginata, C. normalis, C. norvegica, C. nova, C. novae-angliae, C. nudata, C. obispoensis, C. obnupta, C. obtusata, C. occidentalis, C. oklahomensis, C. oligocarpa, C. oligosperma, C. opaca, C. oreocharis, C. ormostachya, C. oronensis, C. ouachitana, C. ovalis, C. oxylepis, C. ozarkana, C. pachystachya, C. paeninsulae, C. paleacea, C. pallescens, C. panicea, C. pansa, C. parallela, C. parryana, C. pauciflora, C. paysonis, C. peckii, C. pedunculata, C. pellita, C. pelocarpa, C. pendula, C. pensylvanica, C. perdentata, C. perglobosa, C. petasata, C. petricosa, C. phaeocephala, C. picta, C. pigra, C. pityophila, C. planispicata, C. planostachys, C. plantaginea, C. platyphylla, C. pluriflora, C. podocarpa, C. polymorpha, C. praeceptorum, C. praegracilis, C. prairea, C. prasina, C. praticola, C. preslii, C. projecta, C. proposita, C. pseudocyperus, C. pumila, C. purpurifera, C. radfordii, C. radiata, C. ramenskii, C. rariflora, C. raynoldsii, C. recta, C. reniformis, C. retroflexa, C. retrorsa, C. richardsonii, C. roanensis, C. rosea, C. rossii, C. rostrata, C. rotundata, C. rufina, C. rupestris, C. ruthii, C. sabulosa, C. salina, C. sartwelliana, C. sartwellii, C. saxatilis, C. saximontana, C. scabrata, C. scabriuscula, C. schottii, C. schweinitzii, C. scirpoidea, C. scoparia, C. scopulorum, C. senta, C. serpenticola, C. serratodens, C. sheldonii, C. shinnersii, C. shortiana, C. siccata, C. silicea, C. simulata, C. socialis, C. sparganioides, C. specifica, C. spectabilis, C. specuicola, C. spicata, C. spissa, C. sprengelii, C. squarrosa, C. stenoptila, C. sterilis, C. stevenii, C. stipata, C. straminea, C. straminiformis, C. striata, C. striatula, C. stricta, C. styloflexa, C. stylosa, C. subbracteata, C. suberecta, C. subfusca, C. subnigricans, C. subspathacea, C. superata, C. supina, C. swanii, C. sychnocephala, C. sylvatica, C. tahoensis, C. tenax, C. tenera, C. tenuiflora, C. tetanica, C. tetrastachya, C. texensis, C. thornei, C. thurberi, C. timida, C. tincta, C. tompkinsii, C. tonsa, C. torreyi, C. torta, C. triangularis, C. tribuloides, C. trichocarpa, C. triquetra, C. trisperma, C. tuckermanii, C. tumulicola, C. turbinata, C. turgescens, C. typhina, C. umbellata, C. unilateralis, C. ursina, C. utriculata, C. vacillans, C. vaginata, C. vallicola, C. venusta, C. vernacula, C. verrucosa, C. vesicaria, C. vestita, C. vexans, C. virescens, C. viridula, C. vulpinoidea, C. whitneyi, C. wiegandii, C. willdenowii, C. williamsii, C. woodii, C. wootonii, C. xerantica
C. aboriginum, C. abrupta, C. abscondita, C. acidicola, C. acutiformis, C. adelostoma, C. adusta, C. aestivalis, C. aggregata, C. alata, C. albicans, C. albida, C. albolutescens, C. albonigra, C. albursina, C. alma, C. alopecoidea, C. amphibola, C. amplectens, C. amplifolia, C. angustata, C. annectens, C. anthoxanthea, C. appalachica, C. aquatilis, C. arapahoensis, C. arcta, C. arctata, C. arctiformis, C. arenaria, C. argyrantha, C. arkansana, C. assiniboinensis, C. atherodes, C. athrostachya, C. atlantica, C. atrata, C. atratiformis, C. atrofusca, C. atrosquama, C. aurea, C. aureolensis, C. austrina, C. austrocaroliniana, C. backii, C. baileyi, C. baltzellii, C. barbarae, C. barrattii, C. basiantha, C. bebbii, C. bella, C. bicknellii, C. bicolor, C. bigelowii, C. biltmoreana, C. blanda, C. bolanderi, C. bonanzensis, C. brainerdii, C. brevicaulis, C. brevior, C. breweri, C. bromoides, C. brunnescens, C. brysonii, C. bulbostylis, C. bullata, C. bushii, C. buxbaumii, C. calcifugens, C. californica, C. canescens, C. capillaris, C. capitata, C. careyana, C. caroliniana, C. caryophyllea, C. castanea, C. cephaloidea, C. cephalophora, C. chalciolepis, C. chapmanii, C. cherokeensis, C. chihuahuensis, C. chordorrhiza, C. circinata, C. collinsii, C. communis, C. comosa, C. complanata, C. concinna, C. concinnoides, C. congdonii, C. conjuncta, C. conoidea, C. constanceana, C. cordillerana, C. corrugata, C. crawei, C. crawfordii, C. crebriflora, C. crinita, C. cristatella, C. crus-corvi, C. cryptolepis, C. cumberlandensis, C. cumulata, C. curatorum, C. cusickii, C. dasycarpa, C. davisii, C. davyi, C. debilis, C. decomposita, C. deflexa, C. densa, C. deweyana, C. diandra, C. digitalis, C. diluta, C. disperma, C. distans, C. disticha, C. divisa, C. divulsa, C. douglasii, C. duriuscula, C. ebenea, C. eburnea, C. echinata, C. edwardsiana, C. egglestonii, C. eleusinoides, C. elliottii, C. elynoides, C. emoryi, C. endlichii, C. engelmannii, C. epapillosa, C. exilis, C. exsiccata, C. extensa, C. festucacea, C. feta, C. filifolia, C. fissa, C. fissuricola, C. flacca, C. flaccosperma, C. flava, C. floridana, C. foenea, C. folliculata, C. formosa, C. fracta, C. frankii, C. fuliginosa, C. garberi, C. geophila, C. geyeri, C. gholsonii, C. gigantea, C. glacialis, C. glareosa, C. glaucescens, C. glaucodea, C. globosa, C. gmelinii, C. godfreyi, C. gracilescens, C. gracilior, C. gracillima, C. granularis, C. gravida, C. grayi, C. grisea, C. gynandra, C. gynocrates, C. gynodynama, C. halliana, C. hallii, C. harfordii, C. hassei, C. haydeniana, C. haydenii, C. heleonastes, C. helleri, C. hendersonii, C. heteroneura, C. heterostachya, C. hirsutella, C. hirta, C. hirtifolia, C. hirtissima, C. hitchcockiana, C. holostoma, C. hoodii, C. hookeriana, C. hormathodes, C. hostiana, C. houghtoniana, C. hyalina, C. hyalinolepis, C. hystericina, C. idahoa, C. illota, C. impressinervia, C. incurviformis, C. infirminervia, C. inops, C. integra, C. interior, C. interrupta, C. intumescens, C. jamesii, C. jonesii, C. joorii, C. juniperorum, C. kobomugi, C. kraliana, C. krausei, C. lachenalii, C. lacustris, C. laeviconica, C. laeviculmis, C. laevivaginata, C. lapponica, C. lasiocarpa, C. latebracteata, C. lativena, C. laxa, C. laxiculmis, C. laxiflora, C. leavenworthii, C. lemmonii, C. lenticularis, C. leporinella, C. leptalea, C. leptonervia, C. leptopoda, C. limosa, C. livida, C. loliacea, C. lonchocarpa, C. longii, C. louisianica, C. lucorum, C. lupuliformis, C. lupulina, C. lurida, C. lutea, C. luzulifolia, C. luzulina, C. lyngbyei, C. mackenziei, C. macloviana, C. macrocephala, C. macrochaeta, C. magellanica, C. manhartii, C. marina, C. mariposana, C. maritima, C. mckittrickensis, C. meadii, C. media, C. melanostachya, C. membranacea, C. mendocinensis, C. merritt-fernaldii, C. mertensii, C. mesochorea, C. michauxiana, C. microchaeta, C. microdonta, C. microglochin, C. micropoda, C. microptera, C. misera, C. missouriensis, C. mitchelliana, C. molesta, C. molestiformis, C. muehlenbergii, C. multicaulis, C. multicostata, C. muricata, C. muriculata, C. muskingumensis, C. nardina, C. nebrascensis, C. nelsonii, C. nervina, C. neurophora, C. nigra, C. nigricans, C. nigromarginata, C. normalis, C. norvegica, C. nova, C. novae-angliae, C. nudata, C. obispoensis, C. obnupta, C. obtusata, C. occidentalis, C. oklahomensis, C. oligocarpa, C. oligosperma, C. opaca, C. oreocharis, C. ormostachya, C. oronensis, C. ouachitana, C. ovalis, C. oxylepis, C. ozarkana, C. pachystachya, C. paeninsulae, C. paleacea, C. pallescens, C. panicea, C. pansa, C. parallela, C. parryana, C. pauciflora, C. paysonis, C. peckii, C. pedunculata, C. pellita, C. pelocarpa, C. pendula, C. pensylvanica, C. perdentata, C. perglobosa, C. petasata, C. petricosa, C. phaeocephala, C. picta, C. pigra, C. pityophila, C. planispicata, C. planostachys, C. plantaginea, C. platyphylla, C. pluriflora, C. podocarpa, C. polymorpha, C. praeceptorum, C. praegracilis, C. prairea, C. prasina, C. praticola, C. preslii, C. projecta, C. proposita, C. pseudocyperus, C. pumila, C. purpurifera, C. radfordii, C. radiata, C. ramenskii, C. rariflora, C. raynoldsii, C. recta, C. reniformis, C. retroflexa, C. retrorsa, C. richardsonii, C. roanensis, C. rosea, C. rossii, C. rostrata, C. rotundata, C. rufina, C. rupestris, C. ruthii, C. sabulosa, C. salina, C. sartwelliana, C. sartwellii, C. saxatilis, C. saximontana, C. scabrata, C. scabriuscula, C. schottii, C. schweinitzii, C. scirpoidea, C. scoparia, C. scopulorum, C. senta, C. seorsa, C. serpenticola, C. serratodens, C. sheldonii, C. shinnersii, C. shortiana, C. siccata, C. silicea, C. simulata, C. socialis, C. sparganioides, C. specifica, C. spectabilis, C. specuicola, C. spicata, C. spissa, C. sprengelii, C. squarrosa, C. stenoptila, C. sterilis, C. stevenii, C. stipata, C. straminea, C. straminiformis, C. striata, C. striatula, C. stricta, C. styloflexa, C. stylosa, C. subbracteata, C. suberecta, C. subfusca, C. subnigricans, C. subspathacea, C. superata, C. supina, C. swanii, C. sychnocephala, C. sylvatica, C. tahoensis, C. tenax, C. tenera, C. tenuiflora, C. tetanica, C. tetrastachya, C. texensis, C. thornei, C. thurberi, C. timida, C. tincta, C. tompkinsii, C. tonsa, C. torreyi, C. torta, C. triangularis, C. tribuloides, C. trichocarpa, C. triquetra, C. trisperma, C. tuckermanii, C. tumulicola, C. turbinata, C. turgescens, C. typhina, C. umbellata, C. unilateralis, C. ursina, C. utriculata, C. vacillans, C. vaginata, C. vallicola, C. venusta, C. vernacula, C. verrucosa, C. vesicaria, C. vestita, C. vexans, C. virescens, C. viridula, C. vulpinoidea, C. whitneyi, C. wiegandii, C. willdenowii, C. williamsii, C. woodii, C. wootonii, C. xerantica
Synonyms C. accedens, C. acutina var. tenuior, C. aperta var. umbrosa, C. aperta var. viridans, C. stylosa var. virens, C. turgidula
Name authority Howe: in H. C. Gordinier and E. C. Howe, Fl. Rensselaer County N.Y., 39. (1894) Boott: in W. J. Hooker, Fl. Bor-Amer. 2: 218, plate 219. (1839)
Web links