Aquatic and Wetland Vascular Plants of the Northern Great Plains
51. Alismataceae, the Water Plantain Family
2. Echinodorus Rich. -- Burhead1. Echinodorus rostratus (Nutt.) Engelm.
Fibrous-rooted annual or perennial 2-6 dm tall, emersed to emergent or sometimes submersed with floating leaves and then nonflowering. Leaves with blades broadly ovate to ovate-lanceolate, more oblong and thin-textured on submersed ones, mostly 3-10 cm long, 1-6 cm wide, rounded at the tip, truncate to cordate or broadly cuneate at the base, gradually tapered and decurrent on the petiole on submersed leaves; petioles trigonous (broadly winged on submersed leaves), mostly longer than the blades. Inflorescence oblong, surpassing the leaves, usually with whorls of 3 branches from lower nodes of the scape, the flowers in whorls of 3-9, the whorls of branches and flowers subtended by spreading, lance-subulate bracts to 10 mm long. Flowers perfect, usually nonshowy; sepals broadly ovate, 4-5 mm long, reflexed in fruit; petals white, from shorter than the sepals to 9 mm long; stamens usually 12; pistils numerous and crowded, long-styled. Fruiting heads globose, 4-6 mm in diameter, appearing burlike due to prominent style beaks; achenes somewhat laterally compressed but turgid, 2.5-3.5 mm long including the straight to curved style beak, strongly ribbed lengthwise on the body. Jul--Sep. Shores, mud flats and alluvial bars, sometimes in shallow water; c and se SD and e NE, principally along the Missouri R. drainage; (DE to IL and SD, s to FL, TX and into Mex; also Ont. and CA).
 |
|
Previous Section -- Alisma plantago-aquatica L.
Return to Family -- Alismataceae - The Water Plantain Family
Next Section -- Sagittaria brevirostra Mack. & Bush
