Calla palustris (Araceae)
Laticifers present, simple, articulated. HABIT : seasonally dormant herb with repent or submersed, green, rhizomatous stem, rooting at nodes. LEAVES : distichous. PETIOLE : sheath long, with long, free, ligulate apex. BLADE : cordate to broadly cordate, rounded, cuspidate-apiculate; primary lateral veins not differentiated, higher order venation parallel-pinnate. INFLORESCENCE : solitary. PEDUNCLE : erect, as long or longer than petiole. SPATHE : fully expanded, elliptic- or ovate-lanceolate, acuminate, shortly decurrent, persistent, white within at anthesis, green without. SPADIX : stipitate, cylindric, obtuse. FLOWERS : bisexual, often male at spadix apex, perigone absent. STAMENS : ca. 6, sometimes more, filaments somewhat flattened, anthers short, connective slender, short, thecae ellipsoid, opposite, dehiscing by longitudinal slit. POLLEN : diaperturate, globose, small (mean 23 µm.), exine foveolate, apertural exine verrucate. GYNOECIUM : shortly ovoid, 1-locular, ovules 6-9, anatropous, oblong, funicles short, placenta basal, style attenuate, stigma small, subhemispheric. BERRY : spheroid-conic, several-seeded, red. SEED : terete-oblong, testa thick, scrobiculate towards chalaza, sulcate-striate towards micropyle, raphe prominent, embryo axile, elongate, endosperm copious.
Creeping helophyte; stem green, rooting at nodes; petiole sheath with long apical ligule; leaf blade cordate; fine venation parallel-pinnate; spathe expanded, elliptic to ovate-lanceolate; flowers bisexual, perigone absent.
Temperate & Subarctic Northern Hemisphere.
In forest swamps, often between forest margins and raised bogs, often with Sphagnum; creeping helophyte in streams and ponds.