Echinodorus berteroi (Sprengel) Fassett
Habit: Annual aquatic herb, with larger (8 to 30 cm.) arrowhead-shaped floating leaves and smaller (3 to 15 cm. wide) submerged leaves. Plants often with runners.
Distribution: Occasional in wet places at low elevation; lakes, ponds, freshwater marshes; California to southeastern U.S., South America.
Seed unit: Achene; compressed, ribbed and tapered to a beak; occasionally free seed.
Seed: Free seed oblong, glandular, with folded embryo.
Embryo: Linear “U” shaped with no endosperm.
Purity instructions: Pure seed definition:
AOSA: PSU #28 – Intact achene, whether or not a seed is present, with or without a beak. Piece of broken achene larger than one-half of the original size unless no seed is present. Seed with or without pericarp/seed coat. Piece of broken seed larger than one-half the original size.
Lab notes: There is often a high percentage of dormant seed in this species; a TZ test is often performed on ungerminated seed.
Average pure seed units per gram: 3,620 seeds per gram (based on AOSA pure seed units only from 8 samples received for testing from 1999 to 2004).
Range of percent pure seed: 94% to 99%
Range of percent inert: 1% to 5%
Description of inert: Plant material.
Planting instructions: 400 seeds, TB, 21 days @ 20°C; for fresh and dormant seed, prechill recommended.
References: (link to main reference page)
Hickman, J.C., Ed. 1993. p. 1101.
Martin, A.C. and W.D. Barkley. 1961. p. 132.
Munz, P.A. and D.D. Keck. 1968. p. 1314
Ransom Seed Laboratory
Smith, C.F. 1998. p. 77.