4. Najas minor All. (brittle naiad)
Pl. 110 e, f; Map 453
10–30 cm long. Leaves 0.5–3.5 cm long, 0.1–0.6 mm wide, ascending to spreading
and becoming recurved late in the growing season, serrulate with multicellular
teeth usually visible without magnification, the tip acute. Leaf bases abruptly
broadened into stipular sheaths, the sheaths auriculate. Seeds 1.5–3.0 mm long,
narrowly fusiform to cylindrical, curved to 1 side at the tip, the surface
purplish brown, dull, finely pitted with 12–18 rows of dense, ladderlike pits
that are short, broad, and rectangular. 2n=12. July–September.
in southern and eastern Missouri (native of Europe, widely naturalized in the
eastern U.S., west to Arkansas). Submerged aquatic in ponds and lakes.
species was first discovered in North America in the Hudson River in 1934
(Meriläinen, 1968). It has since spread rapidly, apparently by migrating
waterfowl. It was first noted in Missouri by Whitley et al. (1990) and will
surely become more widespread in the future.