Pacific Island Ecosystems at Risk (PIER)

  [   PIER species lists  ]   [   PIER home  ]

Hydrolea zeylanica
(L.) Vahl, Hydroleaceae
Click on an image for links to BIGGER PICTURES


Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Other Latin names:  Nama zeylanica L.

Common name(s): [more details]

Chinese: tian ji ma

Habit:  aquatic herb

Description:  "Soft, unarmed, herbaceous perennial, but flowering the first year from seed, therefore seemingly annual, 7-100 cm tall or more, often repent and repeatedly branched, rooting from the lower nodes.   Stems glabrous below the flowering branches.  Leaves glabrous or very thinly puberulent on the petiole, veiny below, lanceolate to elliptic, 2-12 cm long, 6-12 mm wide, on winged petioles up to 5 mm long.  Flowers in irregularly bracted racemes or panicles, the inflorescence branches, pedicels, and calyces stipitate glandular (or merely puberulent, or even entirely glabrous, this eglandular phase apparently rare in Ceylon).  Calyx 5-6.5 mm long, divided nearly to base; corolla blue, glabrous, 5 mm long, lobes spreading.  Stamens not or barely esxert, filaments glabrous, anthers deeply sagitate at base.  Ovary ellipsoid, hairy above, 2.5 mm high in flower.  Styles separate to base, stimas capitate.  Fruit capsular, 4-4.5 mm high, septicidally dehiscent, seated in the persistent calyx; seeds numerous, less than 0.5 mm long" (Dassanayake, 1991; pp. 385-386).

Habitat/ecology:  In China (native), "paddies, pond margins, streamsides, open forests, swampy or inundated soil; 0-1000 m"  (Flora of China online).  In Sri Lanka, "widespread in moist situations around ponds and tnaks, in irrigation ditches, and in wet depressions" (Dassanayake, 1991; pp. 385-386).

Propagation:  Seed, rooting at nodes (Dassanayake, 1991; pp. 385-386).

Native range:  India through southeast Asia, Malesia, China, Taiwan and northern Australia (GRIN).

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 native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Philippines
Philippine Islands
Philippine Islands   Merrill, Elmer D. (1923) (pp. 372-373)
In open wet places, often a common rice-paddy weed.
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)
Northern Territory native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Australia
Australia (continental)
Queensland 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)
Paddies, pond margins, streamsides, open forests, swampy or inundated soil; 0-1000 m. Fujian, Guangdong, Guangxi, Hainan, S Yunnan
Indonesia
Indonesia
Indonesia (Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Malaysia
Malaysia
Malaysia (country of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Singapore
Singapore
Singapore (Republic of) uncertain if introduced
invasive
Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 49)
Weed of uncertain origin
Taiwan
Taiwan Island
Taiwan Island native
Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Paddies, pond margins, streamsides, open forests, swampy or inundated soil; 0-1000 m.
Thailand
Thailand
Thailand (Kingdom of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)
Vietnam
Vietnam
Vietnam (Socialist Republic of) native
U.S. Dept. Agr., Agr. Res. Serv. (2013)


Need more info? Have questions? Comments? Information to contribute? Contact PIER! (pier@hear.org)

  [   PIER species lists  ]   [   PIER home  ]

This page was created on 30 MAY 2005 and was last updated on 14 MAR 2012.