Cyperus sphacelatus Rottb.

Roadside flatsedge (en)

Species

Angiosperms > Poales > Cyperaceae > Cyperus

Characteristics

Annual with fibrous roots. Stems slender to rather firm, tufted, triquetrous, smooth, 10-30(-60) cm by 1-2 mm. Leaves few, shorter than the stems. rather rigid, flat or slightly canaliculate, gradually acuminate, scabrid in the upper half on margins and underside of midrib, 2-4 mm wide. Inflorescence simple or compound, open. Involucral bracts 3-5, obliquely spreading, the lower ones overtopping the inflorescence, up to 20 cm long. Primary rays 3-5(-8), unequal, erecto-patent, slender, smooth, up to 10(-15) cm; secondary rays when present very short, ½-1 cm. Spikes broadly ovoid, usually c. 2 by 3 cm, sometimes up to 5 by 8 cm, with glabrous rachis. Spikelets spicately arranged, 3-10 to the spike, ultimately widely spreading or the lower ones somewhat reflexed, linear-lanceolate, acute, slightly com-pressed, subquadrangular (i.e. rhomboidal in cross-section), 10-20(-50)-flowered, 1-2(-4) cm by c. 2 mm; rachilla flexuous, broadly winged, persistent; internodes ¾-1 mm; wings whitish hyaline, c. ½ mm wide. Glumes membranous, obliquely erect, ovate to elliptic, subobtuse, sometimes minutely mucronulate, 7-9-nerved, 2½-3 by 1½-2 mm;⅓ imbricate; keel green; sides stramineous, usually with a purple spot; margins white-hyaline. Stamens 3; anthers oblong, ½ mm long, Stigmas 3. Nut triquetrous, concave on the ventral side, ellipsoid or slightly obovoid, broadly stipitate, minutely apiculate, brown, 1⅓-1½ by ¾-1 mm.
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Herbs, annual or perennial, cespitose. Culms trigonous, 15–60 cm × 1–3 mm, glabrous. Leaves 2–6, flat to V-shaped, 6–30(–40) cm × 2–4 mm. Inflorescences: spikes broadly ellipsoid, 5–45 × 10–30(–45) mm; rays (2–)5–9, (0.3–)3–10 cm; rachis 4–17 mm; bracts 5–6, horizontal to ascending, V-shaped, 1.5–30 cm × 0.5–4 mm; rachilla persistent, wings hyaline, 0.4–0.5 mm wide. Spikelets 5–30, pale greenish white or stramineous, compressed, linear-lanceoloid, 7–35 × (1.2–)1.4–2 mm; floral scales deciduous, 6–34, spreading or appressed, laterally greenish white, often reddish or brown speckled, medially green, laterally 3–5-ribbed, medially 3-ribbed, elliptic, (2.2–)3–4(–4.4) × (1.2–)1.8–2.2 mm, apex acute. Flowers: anthers 0.6 mm; styles 0.6–1.2 mm; stigmas 1–1.4(–1.7) mm. Achenes reddish brown to dark brown, stipitate, narrowly ellipsoid, 1.4–2 × 0.6–0.9 mm, apex apiculate, surfaces puncticulate.
Annual; culms slender, tufted, 10-60 cm. high; leaves 2-5 mm. wide; bracts long and leaf-like; heads few, loosely ovate, of 5-12 spikelets; spikelets 6-20 mm. long, 2 mm. wide, green or yellowish; scales acute, 2.5 mm. long, striate; achene obovoid, 1.5 mm. long, sharply trigonous, dark lucid brown, smooth.
Generally characterized by the dark red-purple spot at the lower edge of the glume and the golden-green colour of the lower sheaths but both may be absent
Life form annual
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 0.13 - 0.6
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color -
Blooming months -
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

In grassy fields, often as a weed on air-strips, in Brunei collected in Shorea albida peat-swamp.
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Weed of disturbed ground and in damp grassy places.
Light 4-9
Soil humidity 7-9
Soil texture 1-2
Soil acidity -
Soil nutriment -
Hardiness (USDA) 9-12

Usage

Uses animal food material
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) 25 - 30
Germination temperacture (C°) 21 - 23
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Cyperus sphacelatus habit picture by Denis Bastianelli (cc-by-sa)

Leaf

Cyperus sphacelatus leaf picture by Kranthi Kiran (cc-by-sa)

Distribution

Cyperus sphacelatus world distribution map, present in Angola, Australia, Benin, Burkina Faso, Bolivia (Plurinational State of), Brazil, Brunei Darussalam, Central African Republic, Congo, Costa Rica, Cuba, Dominica, Ecuador, Gabon, Ghana, Guinea, Guinea-Bissau, Guyana, Honduras, Haiti, Indonesia, Iceland, Jamaica, Liberia, Madagascar, Mali, Mauritania, Malaysia, Nigeria, Nicaragua, Panama, Peru, Philippines, Papua New Guinea, Puerto Rico, Saudi Arabia, Senegal, Singapore, Sierra Leone, Suriname, Togo, Thailand, Tanzania, United Republic of, Uganda, United States of America, Venezuela (Bolivarian Republic of), Viet Nam, South Africa, and Zambia

Identifiers

LSID urn:lsid:ipni.org:names:135393-3
WFO ID wfo-0000382726
COL ID 33DJ3
BDTFX ID -
INPN ID 446190
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Cyperus chromatolepis Cyperus duchaisingii Cyperus nemorosus Cyperus balbisii Cyperus sphacelatus Cyperus hexastachyos