Blyxa

Scientific name

Blyxa Noronha ex. Thouars

Common names

none

Family

Hydrocharitaceae

Could be confused with

Eriocaulon, Najas, Nechamandra, Vallisneria

Native distribution

West Africa to Australia

Species commonly cultivated

Blyxa alternifolia (Miq.) Hartog

B. aubertii Rich. var. aubertii C.D.K. Cook & Lüönd (Madagascar to Japan to Australia)

B. aubertii Rich. var. echinosperma (C.B. Clarke) C.D.K. Cook & Lüönd (India to Australia)

B. japonica (Miq.) var. alternifolia (Miq.) C.D.K. Cook & Lüönd (Malaysia to Indonesia)

B. japonica (Miq.) var. japonica (Miq.) Asch. & Gürke (India to Japan to Papua New Guinea)

B. novoguineensis Hartog. (Papua New Guinea)

B. octandra (Roxb.) Planch. ex Thwaites (India to Australia)

Adventive distribution

Blyxa aubertii var. aubertii is introduced into Louisiana (United States), while B. japonica var. japonica is established in rice growing areas in northern Italy.

Weed status

often found in rice fields but generally not considered a serious weed

Brief description

Perennial or annual, monoecious or dioecious, rarely stoloniferous. Stem contracted or elongated. Leaves spirally arranged in rosette or opposite on elongate stem, sessile, linear to lanceolate, ribbon-like, venation parallel, midvein prominent; margin finely serrate. Inflorescence solitary or many-flowered, subtended by tubular spathe formed from two fused bracts, sessile or distinctly pedunculate. Flowers bisexual or unisexual, female flower sessile, male pedicellate; sepals 3, distinct, elongate; petals 3, white (rarely reddish), linear to filamentous, flaccid, fringed. Flower opens at or above water surface, pollinated by insects, or remains closed below water surface and is self-fertilized (cleistogamous). Seeds with longitudinal rows of tubercles or spines. Dispersal by seed, stolons or stem fragments.

Natural habitat

ponds and streams

Additional comments

a widely distributed genus containing eleven species from Africa to Australia: four species in Africa, one in Madagascar, and six in warmer regions of Asia to Australia