Scientific Name:
Myriophyllum L., Sp. Pl. 992 (1753)
Type Taxon:
Myriophyllum spicatum L.
Vernacular Name(s):
Milfoil; Water milfoil

Annual or perennial herbs, usually glabrous, monoecious, dioecious, or fls ☿;  stems rooting at nodes, prostrate to erect.  Lvs usually whorled, sometimes opposite or alternate, usually dimorphic, the submerged lvs pectinate and finely divided, the aerial lvs ± entire, rarely all lvs of either form.  Hydathodes often present near lf axils.  Infl. a simple or rarely branched, terminal spike;  fls usually solitary, in the axils of aerial lvs, occasionally in the axils of upper submerged lvs, each with 2 bracteoles; ♂ fls usually above ♀ within same infl. in monoecious spp.  ♂ fls (2)–4-merous;  sepals present;  petals not clawed, ± hooded;  stamens (1)–4 or 8;  filaments short;  anthers linear;  pistil rudiments present or 0. ♀ fls (2)–4-merous;  sepals and petals very reduced or 0;  ovary (2)–4-celled;  styles as many as cells of ovary;  stigmas capitate, fimbriate; staminodes rudimentary.  Fr. of 2–4, 1-seeded mericarps;  mericarps usually smooth and rounded on dorsal face, lacking a differentiated pericarp, sessile or shortly pedunculate.

[From:  Webb et al. (1988) Flora of New Zealand. Volume 4.]

Indigenous (Non-endemic)
Number of species in New Zealand within Myriophyllum L.
Indigenous (Endemic)3
Indigenous (Non-endemic)2
Exotic: Fully Naturalised2