Commelina benghalensis L., Commelinaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 17 (Go to the risk assessment).

Common name(s): [more details]

Cebuano: sabilau

Chinese: fan bao cao

English: Benghal dayflower, Indian dayflower, dayflower, hairy wandering Jew, tropical spiderwort, wandering Jew

French: commeline du Bengale, herbe aux cochons

Hawaiian: hairy honohono

Ibatan: kuhasi

Iloko: kulkulasi

Japanese: tsuyukusa

Pampangan: bias-bias

Samoan: mau‘u Toga, mau‘u toga

Spanish: golondrina, matalí

Tagalog: alikbangon

Tongan: kaningi, kanini, musie matala pulu

Habit:  herb

Description:  "Annual herbs. Roots fibrous. Stems branched, prostrate at base, erect above, rooting at nodes, densely uncinate. Leaves sessile to subpetiolate; blade ovate, 5-7.5 cm long, 3-4 cm wide, apex acute, base obtuse to truncate, puberulous and uncinate above, uncinate beneath; sheath cylindrical, with red stripes, densely uncinate, pilose at margins. Prophyll ca. 1.5 cm long, diameter 3 mm. 1-5 flowering shoots branch from the axils of the leaves, upper cincinnus with 1 enserted male flower; lower cincinnus with 1-3 bisexual flowers; some flowering shoots branch from the prostrate stems, with a single cleistogamous flower enveloped by a bract; spathes infundibuliform, dimorphic: in cleistogamous flowers the bract smaller, obtriangular, ca. 3-5 mm long, uncinate; in chasmogamous flowers the bract larger, obliquely obtriangular, ca. 1.9-1.3 cm long, uncinate; peduncles 0.3-1 cm long; pedicels ca. 1-2 mm long. Flowers zygomorphic, dimorphic: in functionally male flowers pistil abortive and usually lacking or vestigial; in bisexual flowers the pistil ca. 6.5 mm long; sepals 3, greenish, persistent, elliptic, concave, unequal, the anticous 2, basally fused, elliptic, the margins sometimes blue and petaloid, ca. 2-3 mm long, ca.1.4 mm across, glabrous; the posticous one lanceolate, 2 mm long, ca. 1.2 mm wide; petals 3, free, unequal: the lateral petals 2, blue to indigo, equal, planar, clawed, the limb broadly rounded-ovate, 4 mm long, 4-5 mm wide, apex obtuse, base cuneate-cordate, the claw ca. 2 mm long; the medial petal white or blue, small, ca. 3 mm long, ca. 1.8 mm wide; fertile stamens 3, anticous, unequal, the lateral two, anther yellow, triangular, hastate, ca. 0.5 mm long, filament ca. 5.5 mm long; the medial one anther trianglular, hastate, ca. 1 mm long, filament ca. 4 mm long; staminodes 3, subequal, the medial staminodes antesepalous, usually lacking or vestigial, the lateral ones antepetalous, antherodes cruciate, ca. 0.6 mm long, filament ca. 4 mm long; ovary ellipsoid-globose, ca. 1 mm long; style ca. 5.5 cm long. Capsules trilocular, 2-valved, brown, ovoid to ellipsoid, 4-5 mm long, 2-3.5 mm across, the ventral locule 2 seeded, dehiscent, the dorsal locule 1 seeded, usually indehiscent, glabrous. Seeds dimorphic: one in dorsal, brown, elliptic in outline, 2.8-3.5 mm long, 1.9-2.2 mm wide, two in ventral locules black, deltoid in outline, smaller, 1.5-2.2 mm long, 1.5-1.8 mm across, dorsiventral, ventral surface planar, dorsal convex, reticulate, densely with small farinose granules and sparse with large farinose granules"  (Digital Flora of Taiwan).

"Creeping herb with ascending stems; leaves broadly ovate, up to 5 cm long and 4 cm wide, pubescent, narrowed at base but not distinctly petiolate; spathe funnel-shaped, about 1-1.4 cm wide, green, flattened, flowers bright blue"  (Stone, 1970; p. 104).

"Stems prostrate or ascending, often rooting at the nodes, up to 4 dm long, pubescent.  Leaf blades ovate to broadly ovate, 3-5 cm long, 1.5-3 cm wide, puberulent and more or less appressed pilose, apex obtuse, abruptly contracted at base, sheaths 1-2 cm long, pilose and usually long-ciliate in upper part, the hairs rust-colored.  Hypogeous flowers sometimes present, margins of spathe connate at base, 1-1.5 cm long, peduncles more or less exserted from spathe; petals pale blue, 4-5 mm long.  Seeds 5 per capsule, transversely wrinkled"  (Wagner et al., 1999; p. 1379).

Distinguishing characteristics.

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

Habitat/ecology:  "The plant is a serious weed of cultivated crops and is common in plantations and orchards.  It grows best where fertility, soil and air moisture are all high, but will also tolerate dry conditions"  (Swarbrick, 1997; p. 16).

In Hawai‘i, "naturalized in shaded, dry to mesic, disturbed sites, 3-200 m" (Wagner et al., 1999; p. 1379).  "Common to abundant in croplands of Tonga, but only occasional in Samoa" (Whistler, 1988; p. 40). In Tonga, "occasional plantation and waste area weed" (Yuncker, 1959; p. 77).  In Papua New Guinea "A weed of gardens, plantations, waste-land, particularly troublesome in fertile soil under humid conditions"  (Henty & Pritchard, 1975; p. 24).

Propagation:  "It can produce up to 1600 seeds per plant, roots readily at the nodes of creeping stems and regenerates rapidly in this fashion when broken or cut"  (Waterhouse, 1994; p. 56).

Native range:  Tropical Africa and Asia to the Philippines; widely naturalized elsewhere (GRIN).

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	Alamagan Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Alamagan Island	introduced invasive	Fosberg, F. R./Falanruw, M. V. C./Sachet, M.-H. (1975) (p. 18) Voucher cited: Fosberg 31723 (US)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Rota Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Sarigan Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Sarigan Island	introduced invasive	Fosberg, F. R./Falanruw, M. V. C./Sachet, M.-H. (1975) (p. 18) Voucher cited: Evans 2397 (US, BISH, Fo, NY)
Commonwealth of the Northern Mariana Islands (US) Northern Mariana Islands	Tinian Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97)
Commonwealth of the Northern Mariana Islands (US) Saipan	Saipan Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97)
French Polynesia Society Islands	Tahiti Island	introduced invasive	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2013) Adventice
Guam Guam Island	Guam Island	native	Stone, Benjamin C. (1970) (p. 104)
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1987) (p. 97) Native per Stone, introduced per Fosberg et al.
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1379)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1379)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1379)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank L. (2003) (pp. 9-10) Voucher cited: Oppenheimer H110134 (BISH, PTBG)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1379) Voucher cited: Forbes 1221.O (BISH)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands		Kato, Hidetoshi (2007)
New Caledonia New Caledonia	New Caledonia Islands		Swarbrick, John T. (1997) (p. 90)
Papua New Guinea Papua New Guinea (eastern New Guinea Island)	Papua New Guinea (eastern New Guinea Island)	invasive	Henty, E. E./Pritchard, G. H. (1975) (p. 24) At low altitudes, not widely established, but in places very common.
Philippines Philippine Islands	Philippine Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines Philippine Islands	Philippine Islands	native	Merrill, Elmer D. (1925) (p. 195) In open grasslands and waste places in the settled areas at low and medium altitudes, often common.
Samoa Western Samoa Islands	Western Samoa Islands		Whistler, W. A. (1988) (p. 40)
Solomon Islands Solomon Islands	Solomon Islands		Swarbrick, John T. (1997) (p. 90)
Solomon Islands Solomon Islands	Solomon Islands	native	Hancock, I. R./Henderson, C. P. (1988) (p. 59)
Tonga Ha‘apai Group	Ha‘apai Islands		Whistler, W. A. (1992) (p. 83) Vouchers cited: Soakai 832, Soakai 838
Tonga Ha‘apai Group	Tofua Island		Whistler, W. A. (1992) (p. 83) Voucher cited: Scarth-Johnson 57
Tonga Tongatapu Group	‘Eua Island		Whistler, W. A. (1992) (p. 83) Voucher cited: Soakai 899 (EI)
Tonga Tongatapu Group	Tongatapu Island		Whistler, W. A. (1992) (p. 83) Vouchers cited: Lawrence 11, Soakai 539, Soakai 542, Soakai 591, Soakai 739
Tonga Tongatapu Group	Tongatapu Island		Yuncker, T. G. (1959) (p. 77) Voucher cited: Yuncker 15213, Hürlmann 47
Vanuatu New Hebrides Islands	Vanuatu (Republic of)		Swarbrick, John T. (1997) (p. 90)

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)	New South Wales	introduced invasive	National Herbarium of New South Wales (2013)
Australia Australia (continental)	Queensland	introduced invasive	National Herbarium of New South Wales (2013)
Cambodia Cambodia	Cambodia (Kingdom of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Wet places; near sea level to 2300 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shandong, Sichuan, Yunnan, Zhejiang.
Indonesia Indonesia	Indonesia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Honshu, Kyushu, Shikoku
Malaysia Malaysia	Malaysia (country of)		Waterhouse, D. F. (1993) (pp. 64, 76)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, E. (1092) (p. plate)
Singapore Singapore	Singapore (Republic of)	uncertain if introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 28) Weed of uncertain origin
Taiwan Taiwan Island	Taiwan Island	native	Ching-I Peng, ed. (2013) "In semishady and waste places, usually found in rotation crop farms, forest edge and seashore at low altitude".
Thailand Thailand	Thailand (Kingdom of)		Waterhouse, D. F. (1993) (pp. 64, 76)
Vietnam Vietnam	Vietnam (Socialist Republic of)		Waterhouse, D. F. (1993) (pp. 64, 76)
Vietnam Vietnam	Vietnam (Socialist Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)

Indian Ocean
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Indian Ocean offshore islands) Christmas Island Group	Christmas Island	introduced invasive	Swarbrick, J. T. (1997) (p. 110)
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island		Stoddart, D. R./Taylor, J. D., eds. (1971) (p. 147) Actually Commelina diffusa? See Whistler 1996.
British Indian Ocean Territory Chagos Archipelago	Diego Garcia Island	introduced invasive cultivated	Rivers, Julie (2004) (pp. 1, 6)
Maldives Maldive Islands	Maldive Islands		Fosberg, F. R. (1957) (p. 14)
Mauritius Mautitius Islands (Mauritius and Rodrigues)	Mauritius Island		Holm, Leroy G./Plucknett, D. L./Pancho, J. V./Herberger, J. P. (1977) (p. 234)
Seychelles Seychelles Islands	Coetivy Island		Robertson, S. A./Fosberg, F. R. (1983) (p. 147) Voucher cited: Robertson 3141 (K)
Seychelles Seychelles Islands	Marie-Louise Island		Wilson, J. R. (1983) (p. 190)
Seychelles Seychelles Islands	Seychelles Islands	introduced	Invasive Species Specialist Group (2017)

Control: 

Physical: "Germination is difficult to prevent by mulches.  Susceptible to hand weeding, chapping and cultivation, but stems may root if left in contact with soil or plant debris.  May be palatable to pigs.  Can be controlled by competition from tall leafy crops and especially pasture species, but fairly tolerant of shade.  Tolerates dry air and soil conditions" (Swarbrick, 1997; p. 24).

Chemical: Susceptible to: 1) residual herbicides, including simazine, diuron, bromacil and terbacil at standard rates; 2) translocated herbicides, including fluroxypyr at standard rates (Swarbrick, 1997; p. 24).

Biological:  Waterhouse (1994, pp. 56-58) lists natural enemies of this species.