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Aquatic and Wetland Vascular Plants of the Northern Great Plains

Sagittaria L. -- Arrowhead, duck potato

Plants perennial or annual; rhizomes freely produced by perennial spp., often bearing starchy tubers in late summer and fall. Emersed and floating leaf blades usually sagittate with prominent basal lobes, sometimes blades partly or all ovate to lanceolate or elliptic and lacking basal lobes; a basal rosette of thin, lanceolate to linear submersed leaves characteristic of deeply submersed plants, these often preceding floating and emersed leaves, generally absent on flowering specimens. Inflorescence a simple or sparingly branched, bracteate raceme with few to many, mostly 3-flowered whorls, branches sometimes replacing flowers at the lower 1-few nodes of the scape, the inflorescence shorter than to surpassing the leaves. Flowers usually male above and female below in the inflorescence, sometimes partly or even mostly perfect or rarely all of one sex, the male flowers soon falling; sepals greenish, persistent, eventually reflexed or sometimes appressed on the fruiting heads; petals white, showy, ephemeral; stamens many, filaments glabrous or pubescent; pistils numerous, densely crowded on a subglobose receptacle. Achenes crowded in globose or subglobose heads, laterally flattened and winged, sometimes with a low wing on the faces as well, apically beaked with the persistent style, the beak sometimes obscure.

Bogin, C.  1955.  Revision of the genus Sagittaria.  Mem. New York Bot. 	
     Gard. 9:179-223. 

Wooten, J. W.  1973.  Taxonomy of seven species of Sagittaria from 	
     eastern North  America.  Brittonia 25:64-74.

Lead Characteristic Go To
1 Blades of emersed leaves not sagittate, lacking basal lobes or some occasionally with small caudal lobes. Lead 2
1 Blades of emersed leaves mostly or all sagittate, the basal lobes prominent. Lead 3
2 Female flowers and fruiting heads apparently sessile on the scape. S. rigida
2 Female flowers and fruiting heads obviously pedicellate S. graminea
3 Sepals appressed to the fruiting heads; pedicels of fruiting heads inflated; plants annual, lacking rhizomes. S. calycina
3 Sepals reflexed on fruiting heads; pedicels of fruiting heads slender; plants perennial, with rhizomes. Lead 4
4 Floral bracts acute to obtuse, mostly less than 1 cm long; achene beak projecting horizontally from the apex of the achene. S. latifolia
4 Floral bracts acute to acuminate or attenuate, usually more than 1 cm long; achene beak erect or oblique to recurved-ascending. Lead 5
5 Achene beak short, erect, 0.1-0.4 mm long; ventral wing of achene usually convex below the beak; basal lobes of leaf mostly shorter than the terminal one. S. cuneata
5 Achene beak prominent, oblique to recurved-ascending, 0.5 mm or more long; ventral wing of the achene straight below the beak; basal lobes of leaf usually equaling or longer than the terminal one. S. brevirostra

51. Alismataceae, the Water Plantain Family
3. Sagittaria L. -- Arrowhead, duck potato
1. Sagittaria brevirostra Mack. & Bush
2. Sagittaria calycina Engelm.
3. Sagittaria cuneata Sheld.
4. Sagittaria graminea Michx.
5. Sagittaria latifolia Willd.
6. Sagittaria rigida Pursh

Return to Family -- Alismataceae - The Water Plantain Family
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