Monographs Details: Sagittaria graminea Michx. var. graminea
Haynes, Robert R. & Holm-Nielsen, Laurtiz B. 1994. The Alismataceae. Fl. Neotrop. Monogr. 64: 1-228. (Published by NYBG Press
Synonyms:Sagittaria simplex Torr., Sagittaria sagittifolia var. simplex (Pursh) Hook., Sagittaria purshii Rich. ex Kunth, Sagittaria stolonifera Engelm. & A.Gray, Sagittaria lancifolia var. angustifolia (Lindl.) Griseb., Sagittaria graminea var. cycloptera J.G.Sm., Sagittaria cycloptera (J.G.Sm.) C.Mohr, Sagittaria eatoni J.G.Sm., Sagitta graminea (Michx.) Nieuwl., Sagittaria edwardsiana R.T.Clausen, Sagittaria graminea subsp. edwardsiana (R.T.Clausen) R.T.Clausen
Description:Description - Perennial herbs from stolons, rhizomes, or corms, glabrous, to 100 cm tall; stolons 10-15 cm long, 0.5-1 cm wide; rhizomes to 11 cm long, to 2 cm diam.; corms to 3 cm diam. Leaves submersed and/or emersed; submersed leaves sessile,greenish-brown, phyllodia, 6.4-10 cm long, 0.5-4 cm wide, the veins 3-7, the apex acute, the basal lobes absent; emersed leaves petiolate, the petioles triangular, 6.5-13.5 cm long, 0.7-1.2 cm wide, the basal sheath to 12.5 cm, the blades pale green, linear to linear-oblanceolate, 2.5-17.4 cm long, 0.2-4 cm long, the veins 1-3, the apex acute, the basal lobes absent. Inflorescence a simple or paniculate scape of 1-7 whorls, emersed, 2.5-21 cm long, 1-6 cm wide, the whorls with 3 flowers; peduncles terete, 6.5-29.7 cm long, 0.2-4 cm diam. ; staminate bracts united, broadly subulate to lanceolate, coarse, 2-3 cm long, the apex round-acute to obtuse; carpellate bracts united, subulate, coarse, ca. 5 cm long, the apex acute; staminate pedicels spreading, cylindric, 0.5-1.6 cm long, 0.2-0.4 mm diam.; carpellate pedicels spreading, in flower and fruit, cylindric, 0.8-5 cm long, 0.2-0.3 mm diam. Staminate flowers without sterile carpels, the sepals reflexed to spreading, 3-4 mm long, 2-2.5 mm wide, the petals without claws, 5-8.5 mm long, 4-5 mm wide, the stamens ca. 18, the filaments pubescent, dilated, ca. 0.5 mm long, ca. 0.2 mm wide, the anthers elliptic, 0.9-1.1 mm long, 0.6-1 mm wide, the apex obtuse; carpellate flowers without a ring of sterile stamens, the sepals reflexed to spreading in flower and fruit, 3-5 mm long, 1.5-2.5 mm wide, the petals without claws, 6-8 mm long, 5.7-6.3 mm wide. Fruit aggregate 0.6-1 cm diam.; achenes oblanceolate, beaked, without keel, 1.5-2.8 mm long, 1.1-1.5 mm wide, the faces etuberculate, with 1-2 glands, the beak lateral, erect, ca. 0.2 mm long.
Discussion:Bogin (1955) divided Sagittaria graminea into seven varieties on the basis of shape of inflorescences, submersed leaves, and fruits and length of the anthers in relation to the filaments. Only var. graminea and var. platyphylla, according to Bogin’s (1955) systematics, occur in the neotropics. The other five occur in temperate and subtemperate North America. We recognize var. platyphylla as a distinct species, leaving only his var. graminea as a representative of S. graminea from the Neotropics. We accept only one infraspecific rank, however, and that is subspecies. We therefore consider var. graminea at the subspecific level, a level which already exists for the species since Clausen (1939) proposed ssp. edwardsiana.According to Paffrath (1980b, 1981b), the species is sold under the German commercial name "Grasartiges Pfeilblatt" ("Grass-like arrowhead," transl.). Propagation by stolons, as well as from tubercles, which arise as the days become shorter. New plants develop from these tubercles at the beginning of spring. Cultivation is best in medium to large aquaria, where plants tolerate shade and grow well in soft to medium hard water at a pH of 6.0-7.5. The optimum temperature range is from 15° to 30°C. The plants grow more slowly on a washed sand bottom than in clay-containing sand (De Wit, 1971; Mühlberg, 1980).
Distribution:United States of America North America
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