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red-root cyperus, red-root flat sedge, redroot nutgrass

Egyptian paper-reed, papyrus

Habit Herbs, annual, cespitose. Herbs, perennial, rhizomatous, stout.
Culms

trigonous to roundly trigonous, (0.5–)5–25(–105) cm × 1–2.5(–7.5) mm, glabrous.

roundly trigonous, 300–500 cm × 15–45 mm, glabrous.

Leaves

flat to inversely W-shaped, 5–25(–90) cm × 2–5(–11) mm.

bladeless.

Inflorescences

spikes 1–3(–6), rather densely cylindric-ovoid, (4–)10–30(–45) × (6–)10–16(–23) mm;

rays 2–6(–12), 1–8(–28) cm;

bracts (3–)5–7(–11), horizontal to ascending at 30°, inversely W-shaped, (3–)10–20(–70) cm × 1–3(–12) mm;

rachilla persistent, at maturity becoming laterally free, remaining firmly attached proximally, wings 0.3(–0.4) mm wide.

spikes loosely cylindric, 10–20 × 6–10 mm;

rays 40–100, drooping or arching, slender, 10–30 cm; 2d order rays 8–20 cm;

bracts 4–10, ± erect, V-shaped, 3–8 cm × 4–15 mm; 2d order bracts 2–5, (1.5–)4–16 cm × 0.5–2 mm;

rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 mm wide.

Spikelets

(20–)40–80, linear, quadrangular, 3–8(–11) × 1–1.5 mm;

floral scales deciduous, 6–16(–30), appressed, laterally light brown with reddish speckles, medially greenish, laterally ribless, medially 3-ribbed, oblong-ovate to obovate, quadrangular to subterete, 1.3–1.5 × 0.8–1.2 mm, apex obtuse, mucronulate.

6–30, slightly compressed, linear, ± quadrangular, 6–10 × 0.8–1 mm;

floral scales 6–16, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate-elliptic, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse.

Flowers

anthers 0.2–0.3 mm, connectives 0.1 mm;

styles 0.7–0.8 mm;

stigmas 0.4 mm.

anthers 0.8–1 mm (connectives prolonged beyond anther as red subulate appendage 0.2–0.5 mm, apex usually setose);

styles 0.2–0.4 mm;

stigmas 0.8–1.2 mm.

Achenes

light grayish to brown, sessile, ovoid, (0.4–)0.7–1 × 0.4–0.6 mm, apex rounded, apiculate, surfaces glabrous.

pale brown, sessile, oblong, 0.8–1 × 0.4 mm, apex scarcely apiculate, surfaces puncticulate.

Cyperus erythrorhizos

Cyperus papyrus

Phenology Fruiting summer. Fruiting summer.
Habitat Emergent shorelines Stream banks, marshes
Elevation 0–1500 m (0–4900 ft) 0–30 m (0–100 ft)
Distribution
from FNA
AL; AR; AZ; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; WA; WI; WV; MB; ON; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; s Europe; sw Asia; Africa [Introduced in North America]
[BONAP county map]
Discussion

Cyperus papyrus is conspicuous in the field by its great height, leafless culm, and open, hemispheric inflorescence with drooping rays.

Ancient Egyptians, Greeks, and Romans prepared paper from the pith of the culms of Cyperus papyrus, which is abundant along the Nile River.

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

Source FNA vol. 23, p. 172. FNA vol. 23, p. 173.
Parent taxa Cyperaceae > Cyperus > subg. Cyperus Cyperaceae > Cyperus > subg. Cyperus
Sibling taxa
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
Synonyms C. cupreus, C. erythrorhizos var. cupreus, C. occidentalis, C. washingtonensis
Name authority Muhlenberg: Descr. Gram., 20. (1817) Linnaeus: Sp. Pl. 1: 47. (1753)
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