[Limnanthemum S. G. Gmelin, Nov. Act. Acad. Petrop. 14: 527. pl. 17. f. 2. 1769.]

Aquatic perennial herbs, with slender rootstocks. Leaves floating, petioled, ovate or orbicular, deeply cordate, entire or repand, or the primary ones different; flowers yellow or white, polygamous, umbellate at the summit of filiform stems at the bases of the petioles, or axillary, often accompanied by a cluster of thick elongated root-like tubers. Calyx 5-parted. Corolla nearly rotate, deeply 5-cleft, the lobes induplicate-valvate in the bud. sometimes fimbriate on the margins, glandular at the base. Stamens 5, inserted on the base of the corolla; filaments short; anthers sagittate, versatile. Ovary 1-celled; style short or none; stigma 2-lamellate. Capsule ovoid or oblong, indehisccnt or irregularly bursting. Seeds numerous or few, smooth or rough. [Greek, like Nymphaea.]

About 20 species, widely distributed in temperate and tropical regions. The following are the only ones known to occur in North America. Type species: Nymphoides ftava Hill.

Flowers white, accompanied by tufts of root-like tubers; native species. Floating leaves 1'-2' long; flowers 3"-6" broad; seeds smooth.

1 .N. lacunosum.

Floating leaves 2 -6' long; flowers 6"-10" broad; seeds rough.

2. N. aquaticum.

Flowers not accompanied by tufts of tubers; corolla bright yellow, 1 broad or more; introduced species.

3. N. nymphaeoides.

2 Nymphoides Hill Brit Herb 77 1756 42

1. Nymphoides Lacunosum (Vent.) Kuntze. Floating Heart

Fig. 3371

Villarsia lacunosa Vent. Choix des Plantes, 9. 1803. Limnanthemum lacunosum Griseb. Gent. 347. 1839. Nymphoides lacunosum Kuntze, Rev. Gen. Pl. 429. 1891.

Rootstock buried in the mud, the roots long and fibrous. Primary leaves membranous, submerged, short-petioled; stems (stolons) filiform, greatly elongated, sometimes 10° long, bearing a short-petioled floating leaf, an umbel of flowers and a cluster of narrow tubers at its summit, or some of the floating leaves on petioles as long as the stems; floating leaves ovate-orbicular, purplish beneath, 1'-2' long, the basal sinus narrow or broad; pedicels slender; tubers linear-conic, 1/2'-1' long; flowers nearly white, 3"-6" broad; style none; capsule ovoid, covered by the connivent calyx-segments; seeds numerous, smooth.

In ponds. Nova Scotia to Florida, west to Ontario, Minnesota and Louisiana. July-Aug.

2. Nymphoides Aquaticum (Walt.) Kuntze. Larger Floating Heart

Fig. 3372

Anonymos aquatica Walt. Fl. Car. 109. 1788. Villarsia aquatica Gmel. Syst. 1: 447. 1791. Menyanthes trachysperma Michx. Fl. Bor. Am. 1:

126. 1803. Limnanthemum trachyspermum A. Gray, Man. Ed.

5, 390. 1867. Linmanthemum aquaticum Britton, Trans. N. Y.

Acad. Sci. 9: 12. 1889. Nymphoides aquaticum Kuntze, Rev. Gen. Pl.

429. 1891.

Similar to the preceding species but stouter and larger. Floating leaves cordate-orbicular, thick, entire or repand, 2'-6' long, spongy, and with the petioles and stolons densely covered with minute pits; primary leaves spatulate; pedicels slender, 1-3' long; tubers linear-oblong, thicker; corolla white, 6"-10" broad; style none; seeds rough; capsule longer than the calyx.

In ponds, southern New Jersey and Delaware to Florida and Texas. May-Aug.

2 Nymphoides Aquaticum Walt Kuntze Larger Floating 432 Nymphoides Aquaticum Walt Kuntze Larger Floating 44

3. Nymphoides Nymphaeoides (L.) Britton. Water Lily. Floating Heart

Fig. 3373

Menyanthes nymphaeoides L. Sp. Pl. 145. 1753.

Limnanthemum nymphaeoides Hoffm. & Link, Fl. Port. 1: 344. 1809.

Stems long, stout, creeping or buried in the mud, ascending to the surface of the water, branched, the upper nodes bearing a petioled leaf and a cluster of flowers, or the upper internodes very short and their leaves apparently opposite. Petioles stout, mostly longer than the ovate-orbicular firm blades, which are 2'-4' broad; pedicels stout, becoming 3'-6' long, not accompanied by tufts of tubers; flowers bright yellow, 1 in diameter, or more; corolla segments short-fringed; seeds with fimbriate margins.

Naturalized in ponds, District of Columbia. Native of Europe and Asia. May-July.