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flat-spike sedge

prairie straw sedge

Habit Plants densely cespitose; rhizome internodes 0.2–6(–8) mm, 1.6–2.2 mm thick. Plants cespitose; rhizomes appearing elongate in old clumps.
Culms

strongly purple-red to (3.4–)5.5–9.6 cm high at base, 14–60 cm.

uniformly slender, 40–80 cm;

vegetative culms few, inconspicuous, usually fewer than 15 leaves, not strikingly 3-ranked.

Leaves

sheaths glabrous;

blades green, widest blades (3–)3.5–6.5 mm wide, smooth abaxially.

sheaths adaxially conspicuously green-veined nearly to collar, narrow hyaline band or sharp Y-shaped region at collar, adaxially firm, summits U-shaped;

distal ligules 1.6–3.3 mm;

blades 2–5 per fertile culm, 12–18 cm × 1.5–2.5 mm.

Inflorescences

0.55–0.96 of culm height;

peduncles of lateral spikes barely scaberulous or smooth;

peduncles of terminal spike 2.4–49 mm, barely to much exceeding lateral spikes;

proximal bract sheaths tight, abaxially glabrous, sheath front truncate or slightly convex, elongated to 3.1(–4.8) mm beyond apex;

ligules 0.7–3.8(–13.4) mm;

blades uniformly green, distal bract usually much exceeding terminal spike.

stiffly erect, dense to slightly open, brown, 1.5–3(–3.5) cm × 6–14 mm;

proximal internode 2–12 mm; 2d internode 2–7 mm;

proximal bracts scalelike, often with bristletips shorter than or equaling inflorescences.

Spikes

3–6, widely separate or distal 2–3 overlapping;

lateral spikes pistillate, with (2–)5–14 perigynia, (4–)9–24 × (1.6–)2.9–6.4(–6.9) mm, ratio of spike length (in mm) to flower number = 1.5–2.3;

terminal spikes (6–)14–26(–30) × (0.8–)1.3–2.5(–3) mm.

2–5, distant, distinct, ovoid, 7–12 × 4–7 mm, base rounded or short-acute, apex acute.

Perigynia

distichously imbricate, 57–69-veined, unwrinkled, oblong or elliptic to narrowly oblong or narrowly elliptic, obtusely triangular in cross section, (3.9–)4.2–4.9(–5.1) × (1.4–)1.6–1.8 mm, (2.4–)2.5–3.3 times as long as wide, dull, base very gradually tapered, apex gradually tapered;

beak absent or straight, 0–0.3 mm.

15–80 in larger spikes, appressed, usually golden brown, conspicuously 6–9-veined abaxially, inconspicuously veined adaxially, diamond shaped, flat except over achene, 4–5 × 2–2.8 mm, 0.4–0.5 mm thick, base subacute or acute, margin flat, including wing 0.6–0.9 mm wide, smooth;

beak apprressed, golden brown at tip, flat, 0.7–1.6(–1.8) mm, 2/5+ length of body, ciliate-serrulate, abaxial suture with hyaline, golden brown margin, distance from beak tip to achene 2–3 mm.

Achenes

obovoid, 2.8–3.7 × 1.3–1.7 mm, tightly enveloped by perigynia;

stipe straight;

beak straight, (0.3–)0.4–0.7 mm.

elliptic to ovate, 1.5–1.7 × 0.8–1.1 mm, 0.3–0.4 mm thick.

Pistillate

scales 2.8–4.5 × (1.2–)1.7–2.2 mm, margins whitish or tinged pale red-brown, entire, apex with awn 0.3–2.5 mm.

scales reddish brown, 1-veined midstripe sometimes pale, broadly lanceolate, 2.7–3.6 mm, shorter and narrower than perigynia, apex firm, acute to acuminate.

Staminate

scales 3.3–4.9 × 1.1–1.7 mm.

Anthers

2.2–3.2 mm.

2n

= 72.

Carex planispicata

Carex suberecta

Phenology Fruiting spring–early summer. Fruiting early summer.
Habitat Mesic deciduous forests, usually in loams on lower portions of slopes adjacent to streams and on the upper portions of flood plains Calcareous fens and seeps, shores, swales
Elevation 10–800 m (0–2600 ft) 100–600 m (300–2000 ft)
Distribution
from FNA
AL; AR; DC; DE; GA; IL; IN; KY; LA; MD; MO; MS; NC; NJ; OH; OK; PA; SC; TN; TX; VA; WV
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; IA; IL; IN; MI; MN; MO; OH; TX; VA; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
Discussion

Carex planispicata is frequent. Often, it grows with C. abscondita, C. amphibola, and C. oligocarpa. When C. oligocarpa and C. planispicata co-occur, C. planispicata usually grows lower on slopes than C. oligocarpa, though the two do occasionally grow intermingled.

Until its description, Carex planispicata was long treated as C. amphibola or C. amphibola var. rigida (R. F. C. Naczi 1999).

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

Source FNA vol. 23, p. 456. FNA vol. 23.
Parent taxa Cyperaceae > Carex > sect. Griseae Cyperaceae > Carex > sect. Ovales
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. 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. 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. 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. amphibola var. rigida C. tenera var. suberecta
Name authority Naczi: J. Kentucky Acad. Sci. 60: 37, fig. 1. (1999) (Olney) Britton: Man. Fl. N. States ed. 2, 1057. (1905)
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