Flora of Barro Colorado Island

Pistia stratiotes

L., Sp. Pl. 963. 1753

Water lettuce, Lechuga de agua

Floating aquatic, nearly acaulescent; caudex sometimes producing stolons with new rosettes of leaves at apex. Leaves forming dense rosette; petioles very short; blades ± obovate, rounded or emarginate at apex, cuneate at base, mostly 5-17 cm long, 2-7 cm wide, thick and spongy, pubescent on both surfaces with short, few-celled trichomes; veins in 5-15 pairs, parallel, prominent be­neath. Inflorescences small and inconspicuous, subsessile, borne among leaves; spathe white, constricted at middle, the lateral margins connate to middle; spadix shorter than spathe and adnate to it for two-thirds of its length, with a single naked pistillate flower and 2-8 naked    stam­inate flowers arranged in verticils; stamens 2, connate to form a synandrium; ovary obliquely attached to spadix, 1-celled; ovules numerous with basal placentation. Seeds cylindrical, minute. Croat 8431.

Occasional, at the lake margin, usually in quiet waters. Flowering period unknown.

Throughout the tropics of the world. Probably through­out Panama at lower elevations; known from tropical moist forest on both slopes in the Canal Zone and in Panama and Darién.

Photos from STRI Digital Archive

  • Pistia stratiotes
  • Pistia stratiotes
  • Pistia stratiotes