Northern Prairie Wildlife Research Center
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.
Wooten, J. W. 1973. Taxonomy of seven species of Sagittaria from
eastern North America. Brittonia 25:64-74.
||Blades of emersed leaves not sagittate, lacking
basal lobes or some occasionally with small caudal lobes.
||Blades of emersed leaves mostly or all sagittate,
the basal lobes prominent.
||Female flowers and fruiting heads apparently sessile
on the scape.
||Female flowers and fruiting heads obviously pedicellate
||Sepals appressed to the fruiting heads; pedicels
of fruiting heads inflated; plants annual, lacking rhizomes.
||Sepals reflexed on fruiting heads; pedicels of fruiting
heads slender; plants perennial, with rhizomes.
||Floral bracts acute to obtuse, mostly less than
1 cm long; achene beak projecting horizontally from the apex of the
||Floral bracts acute to acuminate or attenuate, usually
more than 1 cm long; achene beak erect or oblique to recurved-ascending.
||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.
||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.
51. Alismataceae, the Water Plantain Family
3. Sagittaria L. -- Arrowhead, duck potato
- 1. Sagittaria brevirostra Mack. &
- 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
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