Monographs Details: Echinodorus tenellus (Mart.) Buchenau
Authority: Haynes, Robert R. & Holm-Nielsen, Laurtiz B. 1994. The Alismataceae. Fl. Neotrop. Monogr. 64: 1-228. (Published by NYBG Press)
Synonyms:Alisma tenellum Mart., Echinodorus tenellus var. ecostatus Fassett, Echinodorus parvulus Engelm., Echinodorus tenellus var. parvulus (Engelm.) Fassett, Echinodorus parvulus f. randii Fassett
Description:Species Description - Annuals, glabrous, to 25 cm tall; stoloniferous. Leaves emersed or submersed; emersed leaves pale green to green-brown, petiolate, the blades linear, entire, with 3-5 veins, 1-7.4 cm long, 2-5 mm wide, the pellucid markings absent, the apex acute, the base attenuate, the petioles terete throughout, 4-5-ridged, 1.2-9.5 cm long, 0.4-0.8 mm diam., the base with a sheath to 1 cm long; submersed leaves pale green, sessile, linear, entire, with 1-3 veins, to 5 cm long, ca. 0.2 cm wide, the apex acute, the sheath to 2 cm long. Inflorescence umbelliform, of 1 whorl, rarely racemose and of 2 whorls, erect, not vegetatively proliferating, overtopping the leaves, to 6 cm long, to 8 cm wide, the whorls with 4-6 flowers, the rachis absent or, if present, terete between whorls; peduncles terete, 1.2-1.0 cm long, 0.1-0.2 mm wide; bracts deltoid, shorter than pedicels subtended, connate about half of length, coarse with delicate margins, 2.8-4.9 mm long, 1-2.1 mm wide, the apex acute; pedicels spreading in flower and fruit, cylindric, 0.5-3 cm long, 0.30.5 mm in diam. Flowers 6-8 mm wide; sepals slightly appressed, with 3-5 veins, 2.5-2.9 mm wide, the veins without papillae; petals clawed, 2.5-4.1 mm long, 1.5-3 mm wide, the claw ca. 1 mm long; stamens 9, the anthers basifixed, ca. 1 mm long, the apex obtuse, the filaments ca. 0.5 mm long; carpels 15-20. Fruit obovate, flattened, 0-3-ribbed, without keel, eglandular, separating when mature, 0.8-1.5 mm long, 0.8-1 mm wide, the beak lateral, erect, 0.1-0.2 mm long.

Discussion:Sold under the German commercial names of "Zartblaettriger Froschloeffel” and “Kleinblaettriger Froschloeffel," and the English names "Pigmy chain-sword" and "Dwarf Amazonian Swordplant" The species can be propagated by rootrunners in medium to large aquaria. It requires considerable light, soft to medium hard water, temperatures above 18° C, and low iron concentration. A substrate of coarse, unwashed gravel (1-3 mm grain diameter) is suitable, but the growth point must not be covered (Mühlberg, 1980; De Wit, 1971, 1982; Walitzki, 1986).
Distribution:Mexico North America| Veracruz Mexico North America| Nicaragua Central America| Zelaya Nicaragua Central America| Cuba South America| La Habana Cuba South America| Piñar del Río Cuba South America| Jamaica South America| Saint Elizabeth Jamaica South America| Dominican Republic South America| Trujillo Venezuela South America| Colombia South America| Boyacá Colombia South America| Meta Colombia South America| Vichada Colombia South America| Venezuela South America| Amazonas Colombia South America| Apure Venezuela South America| Barinas Venezuela South America| Bolívar Venezuela South America| Cojedes Venezuela South America| Guárico Venezuela South America| Portuguesa Venezuela South America| Guyana South America| Rupununi Guyana South America| Brazil South America| Bahia Brazil South America| Goiás Brazil South America| Mato Grosso Brazil South America| Minas Gerais Brazil South America| Pará Brazil South America| Piauí Brazil South America| Rio de Janeiro Brazil South America| Roraima Brazil South America| Santa Catarina Brazil South America| São Paulo Brazil South America| Bolivia South America|