Cyperus digitatus Roxb., Cyperaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Common name(s): [more details]

Chinese: chang xiao sui suo cao

English: digitate cyperus

French: souchet digité

Spanish: cortadera

Habit:  sedge

Description:  "Tall perennial with short, erect, woody rhizome.  Culms tufted or solitary, 60-150 (-200) cm tall, 3-7 mm tick, triquetrous above, trigonous below, smooth.  Leaves few to several, shorter than to equaling the culm; blades linear 1- or 3-costate, flat to plicate, 5-10 (-15) mm wide, herbaceous, or subcoriaceous, scabrous on margins, gradually long-acute at apex; sheaths up to 30 cm long, mostly stained with brownish purple or dusky brown.  Anthela compound or decompound, 15-40 cm long and as wide, rather dense; leafy bracts 3 to 8, patent, most of those overtopping the anthela, the longer ones up to 60 cm long and 10 mm wide, often colored at base with purplish-brown; primary rays 4 to 10, unequal, stiffly patent, smooth, the longer ones 10-30 cm long; secondary rays short, up to 3 cm long; bracteoles shorter than to nearly equaling the anthelule.  Spikes 4 to 10, digitate, cylindrical, 3-6 cm long, 1.5-3 cm wide, sublaxly bearing many spikelets; rhachis narrowly winged, glabrous.  Spikelets rectangularly spreading, linear, 6-20 mm long, 1-1.5 mm wide, weakly flattened, 8-30 (-40)-flowered, straw-coloured; rhachilla straight, the internodes 0.5 mm long, winged, the wings semitranslucent, caducous.  Glumes narrowly elliptic to elliptic, acute at apex, keeled on back, 1.8-2.2 mm long, c. 1 mm wide, membranous, obscurely 1- or 2-nerved along the costa, pale straw-coloured or weakly stained with reddish-brown, the keel greenish or brownish, ending at apiculate apex, not forming a mucro.  Achenes oblong-elliptic to oblong-obovate, trigonous, 0.9-1 mm long, 0.4-0.5 mm wide, yellow-brown; style up to 3 times as long as the achene; stigmas 3.  Stamens 3; anthers 0.5 mm long" (Dassanayake, 1983; p. 170).

Habitat/ecology:  In Venezuela, "damp shores, ditches, marshes, 0-500 m" (Berry et al., 1998; p. 529).

Propagation:  Seed

Native range:  "Pantropic with its range extending north into southern China and Formosa; abundant in South America and southern Asia, relatively scarce in tropical Africa and Australia" (Dassanayake, 1983; p. 170).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Anatahan Island	native	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 66)
Ecuador (Galápagos Islands) Floreana Group	Floreana Island	introduced invasive	Charles Darwin Foundation (2008)
Philippines Philippine Islands	Philippine Islands		Waterhouse, D. F. (1993) (p. 64)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Australia (continental)		Hafliger, E. (1092) (p. 16)
Cambodia Cambodia	Cambodia (Kingdom of)		Waterhouse, D. F. (1993) (p. 64)
China China	China (People's Republic of)		Hafliger, E. (1092) (p. 16)
Indonesia Indonesia	Indonesia (Republic of)		Waterhouse, D. F. (1993) (p. 64)
Malaysia Malaysia	Malaysia (country of)		Waterhouse, D. F. (1993) (p. 64)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, E. (1092) (p. 16)
Negara Brunei Darussalam Brunei	Brunei (Negara Brunei Darussalam)		Waterhouse, D. F. (1993) (p. 64)
Singapore Singapore	Singapore (Republic of)		Waterhouse, D. F. (1993) (p. 64)
Singapore Singapore	Singapore (Republic of)	native	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 31) Common
Thailand Thailand	Thailand (Kingdom of)		Waterhouse, D. F. (1993) (p. 64)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, D. F. (1993) (p. 64)

Additional information:
Additional online information about Cyperus digitatus is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Cyperus digitatus as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Cyperus digitatus may be available from the Germplasm Resources Information Network (GRIN).

References:

Berry, Paul E./Holst, Bruce K./ Yatskievych, Kay. 1998. Flora of the Venezuelan Guayana, vol. 4: Caesalpinianceae-Ericaceae. Missouri Botanical Garden Press, St. Louis. .

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. 2009. A checklist of the total vascular plant flora of Singapore: native, naturalised and cultivated species. Raffles Museum of Biodiversity Research, National University of Singapore. 273 pp.

Dassanayake, M. D., gen. ed. 1983. A revised handbook to the flora of Ceylon. Vol V. Amerind Pub. Co., New Delhi. 476 pp.

Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce. 1987. A geographical checklist of the Micronesian monocotyledonae. Micronesica 20:1-126.

Hafliger, E. 1092. Monocot Weeds 3. CIBA-GEIGY Ltd., Basle, Switzerland. 132 pp. plus plates.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Waterhouse, D. F. 1993. The major arthropod pests and weeds of agriculture in Southeast Asia. The Australian Centre for International Agricultural Research, Canberra. 141 pp.

Zhengyi, Wu/Raven, Peter H./Deyuan, Hong. 2011. Flora of China (online resource).