Cyperus polystachyos Rottb.

IUCN Red List of Threatened Species https://www.iucnredlist.org/species/164195/120160815

Conservation

LC - least concern

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Nativa en Colombia; Alt. 0 - 220 m.; Pacífico, Valle del Magdalena.

Morphology General Habit

Hierba

Conservation

No Evaluada

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Annual, or short-lived perennial with short rhizomes

Morphology Culms

Culms tufted, slender, mostly 20–60 cm tall, usually nearly equalled by the basal leaves

Morphology Reproductive morphology Inflorescences

Inflorescence compound- umbellate (rarely capitate), subtended by several spreading, elongate, leafy bracts

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets linear-lanceolate, chiefly 8–12 mm long, 1–1.5 mm wide, gray- or yellow- brown, densely fasciculate

Morphology Reproductive morphology Fruits

Achenes flattened, brown to black, 1 mm long.

Distribution

Grand Cayman. Pantropical.

Ecology

Often a weed of roadside ditches.

Bernal, R., G. Galeano, A. Rodríguez, H. Sarmiento y M. Gutiérrez. 2017. Nombres Comunes de las Plantas de Colombia. http://www.biovirtual.unal.edu.co/nombrescomunes/

Vernacular

hierba de perro, paja de pisco

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Type

India, ‘In regione Malabarica’, König s.n. (C holotype).

Morphology General Habit

Annual or short-lived perennial, without stolons; culms tufted, more rarely solitary, erect, to 85(100) cm long and 1–3(4) mm wide, triangular, lower part slightly swollen, covered by brown to purplish leaf bases

Morphology Leaves

Leaves basal, sheaths to 15 cm long, pale brown to reddish purple; blade flat, to (25)40 cm long and 1–4 mm wide, scabrid near tip

Morphology Reproductive morphology Inflorescences

Inflorescence 1.5–3 × 2–5.5 cm if head-like, to 7 × 10 cm if with stalked clusters, a congested head-like anthela or more open with one sessile and 2–5 stalked clusters; peduncles of stalked clusters to 4.5(8.5) cm long; spikelets in dense digitate clusters, each cluster with 5–30 spikelets; involucral bracts leaf-like, 2–3 large and 2–4 smaller ones, largest 5–30(45) cm long and 1.5–4 mm wide, scabrid

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 5–15 × 0.8–1.8 mm, linear-lanceolate; rachis straight or zig-zag in fruiting stage; glumes appressed at first, slightly spreading from flowering stage, falling at maturity, pale yellow to brown, ovate, with a narrow white hyaline margin, 1.5–2 × 1–1.5 mm, acute with midrib extended into an often 2–3-fid mucro, keel yellowish brown to green

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2–3; filaments 0.5–2 mm long; anthers c. 0.5 mm long

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma branches 2, c. 1 mm long

Morphology Reproductive morphology Fruits

Nutlet oblong to cylindrical, with very slightly tapering apex, shortly apiculate, shiny metallic grey when mature, 0.5–1 mm long, with numerous minute papillae in longitudinal rows.

Distribution

Botswana, Zambia, Zimbabwe, Malawi, Mozambique. Widespread in all tropical and subtropical regions.

Ecology

Riverbeds and riverbanks, lakeshores, hot springs, sandy beaches, grassland, cultivated areas, usually on drying sandy soils; 0–1450 m.

Conservation

Widespread distribution; Least Concern. In common and widespread habitats.

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Type

Type: None indicated; possibly India,” In regione Malabarica”, König s.n. (C, holo.)

Morphology General Habit

Annual or short-lived perennial, sometimes producing small stolons.

Morphology Culms

Culms tufted, 18–68 cm long, 1–3 mm wide, trigonous to sometimes slightly triquetrous, smooth

Morphology Leaves

Leaf sheath pale yellowish-brown, sometimes with reddish or purplish base, 3–12 cm long. Leaf blade narrowly linear, flattish plicate, 8–48 cm long, 1–4.5 mm wide, acute to acuminate, apex sometimes ± scabrid Leaves up to 57 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts 3–7. Leaf-like, spreading, the lowermost 6.8–35 cm long, (1.4–)2–5.2 mm wide, often folded, sometimes scabrid

Morphology Reproductive morphology Inflorescences

Inflorescence capitate or simple, when simple, primary branches (0–)4–9, (0–)2.7–8 cm long.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 5–30 per cluster, narrowly linear-lanceolate to ovoid-lanceolate, or sometimes narrowly ovoid, 6–19 mm long, 0.8–1.8 mm wide, axis straight to zigzag. Spikelets crowded in dense digitate clusters, sessile or at the end of primary branches, or spikelets clustered at end of primary branch on elongated axis.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes golden yellowbrown to brown-red, (elliptic-)ovate, 1.3–2.3 mm long, 0.6–1.3 mm wide, keel acute or flat to rounded, (0–)1–3-veined, yellowish-brown to green, apex acute to obtuse

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2–3: filaments 0.6–2 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers 0.3–0.6 mm long

Morphology Reproductive morphology Flowers Gynoecium Style

Style 2-branched

Morphology Reproductive morphology Fruits

Nutlet dark brown, sometimes shiny, or grey-brown to dark metallic grey, narrowly oblong to sometimes narrowly oblong-ovoid, 0.7–1.1 mm long, 0.3–0.4 mm wide, minutely punctuate or papillose.