18 MENYANTHACEAE., Vot. III. 
1. Menyanthes trifoliata L, Buckbean. 
Marsh or Bean Trefoil. Bog-bean 
or -myrtle. Fig. 3370. 
Menyanthes trifoliata L. Sp. Pl. 145. 1753+ 
Rootstock thick, scaly, sometimes 1° long, mark- 
ed by the scars of bases of former petioles. Leaves 
3-foliolate; petioles sheathing at the base, 2’~10' 
long; leaflets oblong or obovate, entire, obtuse at 
the apex, narrowed to the sessile base, pinnately 
veined, 14’-3’ long; raceme borne on a long 
scape-like naked peduncle, arising from the root- 
stock, 10-20-flowered; pedicels stout, 3-12” long, 
bracteolate at the base; flowers 5’-6” long; calyx 
shorter than the white or purplish corolla, which 
is bearded with white hairs within; stamens 
shorter than the corolla and style exserted, or 
longer and style nearly included; capsule ovoid, 
obtuse, about 4” long. 
In bogs, Greenland to Alaska, south to Long Island, 
Pennsylvania, Minnesota, Nebraska and California. 
Also in Europe and Asia. Water- or bitter trefoil. 
Water-shamrock, Moon-flower. Marsh-clover. Bitter 
worm. Bog-nut. Brook-bean. May-July. 
2. NYMPHOIDES Hill, Brit. Herb. 77. 1756. 
[LrmnanTHEMUM S. G. Gmelin, Noy. Act. Acad. Petrop. 14: 527. pl. 17. f. 2. 1760.] 
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, indehiscent or irregularly bursting. Seeds 
numerous or few, smooth or rough. [Greck, 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 flava 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, 
1. Nymphoides lacunédsum (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, 4’-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, Min- 
nesota and Louisiana. July—-Aug. 
