Onagraceae |
| 22 genera, 2 contain aquatic species. As far as the
genus Ludwigia concerns: Annual or perennial,
sometimes woody at base. Stems erect, ascending or
creeping and often rooting at the nodes, when submerged
or floating often swollen and spongy or bearing
silverwhite, inflated pneumatophores. Leaves cauline or
in floating rosettes, opposite or alternate, mostly
entire; stipules absent or reduced. Flowers bisexual,
actinomorphic, borne singly or clustered in the axils of
leaves, or in a terminal inflorescence. Sepals (3-) 4
(-7), adnate to the ovary, persisting in fruit. Petals as
many as sepals or absent, yellow or white, entire or
notched at apex, contorted in bud. Stamens as many or
twice the number of sepals; anthers versatile or
basifixed. Ovary inferior, as many locules as sepals;
stigma slightly lobed, hemispherical or capitate;
placentation axile; fruit a capsule, dehiscing by
longitudinal slits or flaps, by terminal pores, or
irregularly; seeds numerous, sometimes dimorphic with
some smooth and others corky. Found in a large variety
of aquatic habitats, submerged, floating, emergent or
seasonally submerged: entomophilous: diaspores seeds,
sometimes dimorphic, some dispersed by water, others by
unknown means: some reported to be weeds in irrigation
systems, other cultivated for decoration. |
