Sphenoclea zeylanica Gaertn., Sphenocleaceae

Click on an image for links to BIGGER PICTURES

Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

Chinese: jian ban hua

English: chickenspike, gooseweed, hollowstem, wedgewort

Filipino: mais-mais

Spanish: sfenoclea

Tagalog: silisilihan

Habit:  herb

Description:  "Roots numerous, long, cord-like.  Stem hollow, up to 150 cm tall, often much branched.  Leaf-blade oblong to lanceolate-oblong, attenuate at both ends, acute or obtuse, 2.5-12.5 cm long; petiole up to 3 cm long.  Spikes cylindric, up to 7.5 cm long, narrowed at apex; peduncle up to 8 cm long.  Bracts and bracteoles spatulate, the tips arched over the flowers except during anthesis.  Flowers densely crowded, though characteristically only 1 or 2 open at a time, rhomboid or hexagonal by compression, sessile, wedge-shaped below, attached longitudinally to the rhachis by a linear base.  Calyx-segments deltoid-semicircular, obtuse, ultimately slightly accrescent and connivent.  Corolla whitish, pinkish or purplish, 2.5-4 mm long; segments ovate-triangular, obtuse or acute, united about half-way, connivent.  Filaments slightly dilated at base.  Ovary obovoid, 2.5 mm long, apex broad, free, truncate.  Capsule 4-5 mm diameter, dehiscing below the calyx-segments which fall with the lid, leaving the scarious base persistent on the rhachis. Seeds yellowish-brown, 0.5 mm long"  (Shaw, 1968; pp. 1-2).

Illustration by International Rice Research Institute (IRRI) courtesy Ecoport.

Habitat/ecology:  "Thrives in almost any kind of damp ground at altitudes below 350 m.  It is found along the sides of ponds, ditches, and rivers, and on dry riverbeds.  It grows in seasonal swamps or depressions which are periodically inundated and prefers stagnant water sites. (Holm et al., 1977; p. 446).  "In and near pools, swamps, streamsides, periodically inundated depressions, ditches, irrigation channels, and wet places generally, 0-1250 m" (Shaw, 1968; pp. 1-2).

Propagation:  Seed

Native range:  "Widespread in tropical Africa (excluding the NE Horn) extending south to the Transvaal; also in Madagascar; widespread (but probably introduced) in tropical Asia and America" (Shaw, 1968; pp. 1-2).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Philippines Philippine Islands	Philippine Islands	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
Philippines Philippine Islands	Philippine Islands		Merrill, Elmer D. (1923) (p. 588) In open wet places; often a rice-paddy weed.
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 97)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 110)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Cambodia Cambodia	Cambodia (Kingdom of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
China China	China (People's Republic of)	introduced invasive	Li-ying, Li/Ren, Wang/Waterhouse, D. F. (1997) (pp. 174, 179)
China China	Hong Kong	native	Wu, Te-lin (2001) (p. 259) In wet places.
Indonesia Indonesia	Indonesia (Republic of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
Japan Japan	Japan	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 189)
Malaysia Malaysia	Malaysia (country of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
Negara Brunei Darussalam Brunei	Brunei (Negara Brunei Darussalam)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
Taiwan Taiwan Island	Taiwan Island	introduced invasive	Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 448)
Thailand Thailand	Thailand (Kingdom of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)
Vietnam Vietnam	Vietnam (Socialist Republic of)	introduced invasive	Waterhouse, D. F. (1993) (pp. 69, 78)

Control: 

Biological:  Waterhouse (1994, pp. 230-231) lists the natural enemies of the species.