Home / Anomalous_Items / Aquatic_Macrophytes / Emergent_Leaves / Sparganium
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Name derivation:
Gk. sparganon = ‘swaddling band’ referring to long narrow leaves.
Classification:
Sparganium Linnaeus; 14 species descriptions are currently recognized taxonomically (Cook and Nicholls 1987). Order Poales; Family Typhaceae Monocot, perennial, monoecious, imperfect (unisex) flowers.
Morphology:
Rhizomatous, oxygenated from leaves through extensive aerenchyma. Upright stem supports long narrow leaves attached alternately. Plants may extend ~2 m above water surface. Floral arrangement is in spherical heads either sessile or on short branches, smaller heads with staminate flowers near apex of floral spike, larger heads bearing pistillate flowers lower on spike. Wind pollinated. Fruits are achenes with beak-like protuberances at their distal end. Sexual reproduction (with seed dispersion) is favored in young recently-established populations of Sparganium erectum, switching toward more clonal reproduction in older populations (Piquot et al. 1998).
Similar genera:
Typha (cattail) is the closest known relative but is easily recognized by its compact brown sausage-like floral spike.
Habitat:
Freshwater, shallow sites in marshes and lakes. Food source for wildlife.
Seed dispersal by fish:
The effective dispersal of S. emersum seeds by carp is not affected by seed size. Larger seeds have greater survival after passing through the carp gut, but this is counterbalanced by greater ingestion of small seeds (large seeds are ejected by ‘spitting’). There is no seed size selective pressure by carp. Likely dispersal distance is calculated to be 13.4 – 27 km (Pollux et al. 2007).
References:
Cook, C.D.K. and M.S. Nicholls (1987) A monographic study of the genus Sparganium (Sparganiaceae). Part 2: Subgenus Sparganium. Botanica Helvetica 97:1-44 Piquot, Y., D. Petit, M. Valero, J. Cuguen, P. de Laguerie and P. Vernet 1998. Variation in sexual and asexual reproduction among young and old populations of the perennial macrophytes Sparganium erectum. Oikos 82:139-148. Polluc, B.J.S., N.J. Ouborg, J.M. Van Groenendael and M. Klaassen 2007. Consequences of intraspecific seed-size variation in Sparganium emersum for dispersal by fish.