Limnophila

Scientific name

Limnophila R. Br.

Common names

ambulia, Asian marshweed

Family

Plantaginaceae

Similar genera

Cabomba, Gratiola, Hottonia, Macbridea, Mentha, Mimulus, Myriophyllum, Pogostemon, Proserpinaca, Ranunculus

Native distribution

tropical Asia, Australasia, Africa

Species cultivated

Limnophila aquatica Roxb.

L. aromatica (Lam.) Merr. (L. aromaticoides Yang & Yen)

L. australis Wannan & J.T. Waterh.

L. brownii Wannan

L. heterophylla (Roxb.) Benth.

L. indica (L.) Druce

L. rugosa (Roth) Merr.

L. sessiliflora (Vahl) Blume

U.S. Federal Noxious Weed: Limnophila sessiliflora

Identification: Limnophila sessiliflora is one of 13 aquatic to amphibiousamphibious:
(adj) of a plant able to live on land or in water
species of Limnophila, all of which are highly polymorphicpolymorphic:
(adj) displaying multiple forms (of, e.g., an organ) in one organism
in phenology. Consultation with published literature is recommended for accurate identification of this species. The small sessilesessile:
(adj) attached directly, without a stalk
flowers are somewhat typical of this species, but not reliable as a sole diagnostic feature.

See Limnophila sessiliflora disseminule fact sheet.

Adventive distribution

North America

Weed status

L. sessiliflora (Vahl) Blume is an aquatic weed on the U.S. federal noxious weed list.

Habit

submersed, emergentemergent:
(adj) (syn. emersed) with parts raised out of the water; extending up out of the water
, and amphibiousamphibious:
(adj) of a plant able to live on land or in water
stem plant

Brief description

Annual or perennialperennial:
(adj) (of a plant) having a life cycle of more than two years
, rooted. Stems ascending or creeping; adventitiousadventitious:
(adj) of an organ growing where it is not normally expected, e.g., roots growing from a stem
roots produced from leaf nodes. Leaves highly variable in shape, caulescentcaulescent:
(adj) having a more or less well developed above-ground stem
, decussatedecussate:
(adj) arranged along stem in pairs, with each pair at right angles to the pairs above and below
or whorledwhorled:
(n) bearing whorls; a type of leaf arrangement (phyllotaxis) in which leaves are in whorls
, sessilesessile:
(adj) attached directly, without a stalk
or petiolatepetiolate:
(adj) relating to or in the form of a petiole; bearing petioles
, distinctly heterophyllousheterophyllous:
(adj) with dissimilar leaves on the same plant; often occurs on plants with both submersed and emersed leaves
between submersedsubmersed:
see submerged
and emersedemersed:
see emergent
forms; emersedemersed:
see emergent
leaf bladeblade:
(n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)
entire, ovateovate:
(adj) egg-shaped in outline; generally with the broad end at or near the base
to lanceolatelanceolate:
(adj) lance-shaped; widest point below the middle, tapering to the apex
; submersedsubmersed:
see submerged
blades often highly pinnatisectpinnatisect:
(adj) pinnately cut or lobed to the midrib
; venationvenation:
(n) the arrangement of veins in a leaf
pinnatepinnate:
(adj) in the form of a feather; of, e.g., leaflets, lobes, or veins: arranged in two rows along an axis
. Flowers solitary in leaf axils or in terminalterminal:
(adj) at the apex
or axillaryaxillary:
(adj) in, of, or produced from an axil
spikes or leafy racemes, sessilesessile:
(adj) attached directly, without a stalk
or pedicellatepedicellate:
(adj) borne on a pedicel
; sepals 5, subequal; corollacorolla:
(n) the inner whorl(s) of the perianth; all the petals of a flower
tubular or funnel shaped, 2-lipped; adaxialadaxial:
(adj) pertaining to the side facing toward the axis, as in the upper surface of a leaf
lip entireentire:
(adj) having a continuous margin that is not toothed or lobed
or 2-lobed; abaxialabaxial:
(adj) the side facing away from the axis, as in the underside of a leaf
lip 3-lobed; white, pink, purple or blue, sometimes with conspicuous spots. Dispersal by numerous seeds or by stem fragments.

Natural habitat

rivers, lakes, and swamps

Additional comments

Limnophila contains 18 accepted species and several unresolved names, of which 13 are considered aquatic. Most species have an aromatic (‘turpentine’) odor when damaged. There is confusion concerning the identity of the species traded as L. aromatica and L. aromaticoides. Some authorities separate the two species based on the arrangement of submersedsubmersed:
see submerged
leaves (opposite or 3-whorled in L. aromatica; 3 to 10-whorled in L. aromaticoides). Recent consensus suggests that L. aromatica is simply a highly variable species in flower color and leaf arrangement, and L. aromaticoides is one such variety. Limnophila aromatica, also know as Rau om or Rau ngo (in Vietnamese), is sold widely as a fresh herb to garnish and flavor soups and curries. Limnophila aromatica is commonly confused with Penthorum sedoides (also known as wavy Limnophila). Species of Limnophila have highly variable leaf shape among species and between growth forms. Some species have a highly dissecteddissected:
(adj) (of leaves) +/- deeply divided, cut, or lobed, including being compound
submersed leaf shape, with simple emersedemersed:
see emergent
leaves; in other species both submersedsubmersed:
see submerged
and emersedemersed:
see emergent
leaves are simple with a slightly serrated marginmargin:
(n) edge; rim
. There are numerous Limnophila species in the trade where the species name is unknown.