Herbs, wetland. Rhizomes horizontal. Leaves appearing before flowers, several, emergent, arising along rhizome, also clustered terminally; petiole 1.5--2 or more times as long as blade; blade bright green, simple, not peltate, ovate to nearly round, base cordate, apex short-acuminate to apiculate; lateral veins parallel. Inflorescences: peduncle erect, as long as or longer than petiole, apex not swollen; spathe white, often green or partially green abaxially, not enclosing spadix; spadix cylindric. Flowers all bisexual or distal ones staminate; perianth absent. Fruits not embedded in spadix, red. Seeds 4--9(--11), embedded in mucilage. x = 18.
Herbs, perennial. Rhizome creeping. Leaves several, distichous; petiole sheathing; sheath ligulate, long; leaf blade broadly ovate-cordate to cordate-orbicular, apex acute to acuminate; venation parallel-pinnate. Inflorescence solitary, flowering with leaf appearance; peduncle erect. Spathe persistent, fully expanded, elliptic to ovate, base decurrent, apex acuminate. Spadix stipitate, cylindric, apex obtuse. Flowers numerous, densely arranged, bisexual, naked (perigone absent), only uppermost flowers often male. Stamens free, usually 6, sometimes more (9-12); filaments flattened; anthers dorsifixed; connective short and slender; thecae ellipsoid, dehiscing by longitudinal slit; pollen grains diaperturate, globose, small, exine foveolate and apertural exine verrucate. Pistil ovoid, 1-loculed; ovules 6-9 (rarely more), anatropous and oblong; funicle distinct; placenta basal; stylar region attenuate; stigma subhemispheric, small. Infructescence subglobose to broadly ellipsoid. Berry globose-conic, with many seeds (usually 4-9). Seed oblong-cylindric to somewhat ellipsoid; testa thick, scrobiculate toward chalaza and sulcate-striate toward micropyle; raphe prominent; embryo axile, elongate; endosperm copious. 2n = 36, 54, 72.
"Fls all perfect, or the upper staminate, covering the spadix; spathe expanded, not enclosing the spadix, ovate to elliptic; perianth none; stamens 6; filaments narrow, flat; anthers short and broad; ovary unilocular, with several erect anatropous ovules; fr a red berry, the few seeds surrounded by gelatinous material; perennial herbs with petioled basal lvs and solitary spathes. Monotypic."
Dudley, M. G. 1937. Morphological and cytological studies of Calla palustris. Bot. Gaz. 98: 556--571. Lehmann, N. L. and R. Sattler. 1992. Irregular floral development in Calla palustris (Araceae) and the concept of homeosis. Amer. J. Bot. 79: 1145--1157. Scribailo, R. W. and P. B. Tomlinson. 1992. Shoot and floral development in Calla palustris. Int. J. Pl. Sci. 153: 1--13.
|Water arum arum, wild calla [a plant name used by Pliny, perhaps from Greek kallos, beauty]|