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many-rib sedge

Assiniboia sedge

Habit Plants densely cespitose. Plants densely cespitose, also producing long-arching stolons that root at the tip and form new plants.
Culms

14–110 cm.

dark maroon at base; flowering stems 35–75 cm, longer than leaves at maturity, 0.5–0.8 mm thick, glabrous or minutely scabrous on angles, especially within inflorescence.

Leaves

sheaths adaxially white-hyaline, summits U-shaped to rounded, often prolonged to 3 mm beyond collar;

distal ligules (1.5–)2–3.5 (–5) mm;

blades 3–4(–5) per fertile culm, 8–25 cm × (2–)3–5 mm.

basal sheaths maroon, bladeless, glabrousl;

others grading from maroon to green on back, pale hyaline on front;

blades flat, 1–3 mm wide, glabrous on adaxial surface, often strigose on abaxial surface, margins and midribs of abaxial surface scabrous at distal end.

Inflorescences

dense, brown or gold, usually ± triangular, 1.6–3 cm × 12–20 mm;

proximal internode 3–5.5 mm; 2d internode 1.5–5 mm;

proximal bracts scalelike or bristlelike, shorter than inflorescences.

peduncles of lateral spikess 20–60 mm, glabrous;

peduncle of ternimal spike 40–60 mm, glabrous or minutely scabrous on angles;

proximal bracts much shorter than inflorescence;

sheaths 15–25 mm;

blades 1.5–2.2 mm wide.

Spikes

4–6(–10), densely aggregated or, sometimes, proximal 1 distant, narrowly to broadly ovoid, (8.5–)10–12 × 6–11 mm, base rounded to attenuate, apex truncate to acute.

Perigynia

ascending to ascending-spreading, green and white, gold, or light brown, conspicuously (8–)10–17-veined abaxially, conspicuously (0–)4–12-veined adaxially, at least 3 adaxial veins longer than achene, usually ovate or broadly ovate, plano-convex, (3.8–)4.4–5.5(–6) × (1.4–)1.8–2.5 mm, 0.5–0.8 mm thick, margin flat, including wing (0.2–)0.3–0.4(–0.5) mm wide, ciliate-serrulate distally;

beak gold to dark brown at tip, flat, ± ciliate-serrulate, abaxial suture inconspicuous or with conspicuous white margin, distance from beak tip to achene 2–2.8(–3.3) mm.

green, at least body maturing to yellow, 2-ribbed but not obviously otherwise veined, except sometimes near base, tightly enveloping achene, lance-ellipsoid, 5–6.5 × 0.8–1.8 mm, cartilaginous, base with stipe 0.5 mm, apex tapering gradually to beak, short-pubescent;

beak oblique to minutely toothed, 2.5 mm.

Achenes

elliptic to broadly ovate, 1.7–2.4 × 1.1–1.7 mm, 0.4–0.6 mm thick.

stipitate, 1.8–2.5 × 0.7–1 mm, stipe adnate to thickened perigynium base, breaking from achene at maturity.

Pistillate

scales gold or light red-brown, often with pale or green midstripe, ovate to lanceolate, (3.2–)3.9–4.8 mm, longer and narrower than perignyia, margin white, 0.1–0.5 mm wide, apex acuminate.

scales pale hyaline, often partially suffused with chestnut brown, with narrow green midrib, lanceolate to oblong, shorter than mature pergiynia, apex cuspidate or acuminate with serrulate green awn 1–3 mm, glabrous.

Lateral

spikes 2–5, pistillate with fewer than 10 perigynia attached 3–15 mm apart, 1 spike per node, well separated, erect or drooping, linear, 5–30 × 3–5 mm;

distal spikes sometimes staminate and shorter than terminal spike.

Terminal

spike staminate, 11–30 × 1.5–3 mm.

2n

= 32.

Carex multicostata

Carex assiniboinensis

Phenology Fruiting late spring–mid summer. Fruiting summer.
Habitat Dry soils Floodplain forests, old river channels and riverbanks, mesic deciduous and mixed conifer-hardwood forests, thickets
Elevation 100–3500 m (300–11500 ft)
Distribution
from FNA
CA; ID; MT; NV; OR; UT; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
IA; MI; MN; ND; SD; WI; MB; ON; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

While Carex multicostata and C. specifica are usually quite distinct, the perigynia of C. multicostata are sometimes lanceolate and strongly resemble those of C. specifica. The type specimen of C. multicostata has unusually elongate inflorescences resembling those of C. specifica, rather than ± short-triangular inflorescences usually present in C. multicostata.

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

Carex assiniboinensis is easy to recognize in mid to late summer because it forms long-arching stolons that root at the tip to form new plantlets. The stoloniferous habit, which was given taxonomic status as C. assiniboinensis forma ambulans by J.-P. Bernard (1959), is typical for the species. Although some herbarium specimens lack the stolons because they were collected early in the season, most if not all populations appear to form the stolons by late summer.

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

Source FNA vol. 23, p. 377. FNA vol. 23, p. 468.
Parent taxa Cyperaceae > Carex > sect. Ovales Cyperaceae > Carex > sect. Hymenochlaenae
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. 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
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. 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
Name authority Mackenzie: Bull. Torrey Bot. Club 43: 604. (1917) W. Boott: Bot. Gaz. 9: 91. (1884)
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