Proserpinaca

Scientific name

Proserpinaca L.

Common names

mermaid weed

Family

Haloragaceae

Similar genera

Gratiola, Hottonia, Limnophila, Myriophyllum, Pogostemon

Native distribution

North America

Species cultivated

Proserpinaca palustris L.

P. pectinata Lam.

Adventive distribution

information not available

Weed status

not weedy

Habit

amphibious amphibious:
(adj) of a plant able to live on land or in water
stem plant, stems ascending, with variably dissecteddissected:
(adj) (of leaves) +/- deeply divided, cut, or lobed, including being compound
leaves

Brief description

Perennial. Stem erect, ascending or prostrateprostrate:
(adj) growing closely along the ground
. Rhizomerhizome:
(n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns
slender, horizontal. Leaves alternatealternate:
(adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights
, sessilesessile:
(adj) attached directly, without a stalk
; leaf bladeblade:
(n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)
highly variable in shape, typically pinnatepinnate:
(adj) in the form of a feather; of, e.g., leaflets, lobes, or veins: arranged in two rows along an axis
, but ranging from pinnatepinnate:
(adj) in the form of a feather; of, e.g., leaflets, lobes, or veins: arranged in two rows along an axis
to entireentire:
(adj) having a continuous margin that is not toothed or lobed
within a single plant; emersedemersed:
see emergent
leaves sometimes entireentire:
(adj) having a continuous margin that is not toothed or lobed
with serrateserrate:
(adj) (of a leaf margin) bearing sharp teeth pointing forward or to the apex
marginmargin:
(n) edge; rim
. Inflorescenceinflorescence:
(n) the arrangement of flowers on the floral axis
of solitary flowers, sessilesessile:
(adj) attached directly, without a stalk
in leaf axils. Sepals 3; petals absent; stamens 3. Dispersal by seed or stem fragments.

Natural habitat

shallow marginal waters of lakes, rivers, swamps, ponds, and wet ground

Additional comments

Proserpinaca contains two species from eastern North America. Its leaf morphology is highly variable, which leads to taxonomic problems. When growing emersedemersed:
see emergent
, P. pectinata has completely pinnatepinnate:
(adj) in the form of a feather; of, e.g., leaflets, lobes, or veins: arranged in two rows along an axis
leaves, while P. palustris has entireentire:
(adj) having a continuous margin that is not toothed or lobed
, but serrateserrate:
(adj) (of a leaf margin) bearing sharp teeth pointing forward or to the apex
leaves. Both species are frequently cultivated for ponds and aquaria.