Sagittaria guayanensis subsp. guayanensis
Content
Description
Herb, perennial, to 50 cm tall, glabrous or sparsely pubescent; corms ca. 2.5 x ca. 3 cm. Leaves submersed or floating; submersed leaves sessile, pale green to greenish-brown, phyllodial, 0.4-0.7 x 0.4-0.8 cm, apex round acute to obtuse, basal lobes present, veins 3-5; floating leaves petiolate, petiole triangular, to 42 x 0.05-0.6 cm, basal sheath to 10 cm long, blade pale green, sagittate to hastate, 3.5-10.5 x 1.5-8.5 cm, apex round-acute, base cordate, sagittate, or hastate, basal lobes present, tips separated by 0.7-6.5 cm, veins 11-13. Inflorescence a simple scape of 1-7 whorls, floating, 0.9-9 x 0.6-4 cm, whorls with 3 flowers; peduncle terete, 10.9-22 x 0.09-0.5 cm; staminate bracts separate, delicate, elliptic to linear, 2.8-5.5 mm long, apex round, acute to obtuse; carpellate bracts separate, delicate, broadly elliptic, 9.4-15 mm long, apex obtuse; staminate pedicels spreading to erect, glabrous to densely pubescent, cylindric, 0.7-1.8 x 0.04-0.12 cm; carpellate pedicels erect to spreading in flower, spreading to reflexed in fruit, glabrous or rarely pubescent, cylindric, 0.6-2.1 x 0.12-0.21 cm. Staminate flowers: sepals erect, 5.5-10 x 3.8-5.2 mm, petals clawed, 6-8.4 x 4-6 mm, stamens 6, filaments glabrous, cylindric, ca. 1.5 x ca. 0.2 mm, anthers linear, 0.6-1.5 x ca. 0.3 mm, apex round acute, sterile carpels present. Carpellate flowers: sepals erect in flower and fruit, 4.5-10 x 2.5-10 mm, petals clawed, 8-10 x 5-7 mm, with ring of sterile stamens. Fruit aggregate 0.5-1.8 cm diam.; achenes obelliptic, 1.7-2.2 x 1.2-1.5 mm, tuberculate, without glands, with 1-3lateral wings, margin echinate, beak lateral, erect, 0.2-0.5 mm long.
Distribution
C America present, C Mexico present, Dominican Republic present, Guianas present, Jamaica present, S America present, Southern America: Paraguay (Paraguay present), northern Argentina present, southeastern U.S.A present
from southeastern U.S.A., Jamaica, Dominican Republic, and C Mexico S throughout C America and S America to Paraguay and northern Argentina; over 100 collections examined, including 22 from the Guianas (GU: 15; SU: 5; FG: 2).
Notes
The holotype of S. guayanensis in P is lost, the isotype is an insufficient fragment in MO; Rataj (1972: 10) selected Hostmann 870 as a neotype, which is, according the nomenclatural rules, an epitype.
The PaleotropicS. guayanensis subsp. lappula (D. Don) Bogin has the achenes compressed and more than 2.5 mm long.
The Paleotropic