Aquatic herbs with cordate or peltate, usually floating, leaves. Floating flowers on long immersed peduncles. Petals and stamens generally numerous.
1. Brase'nia. Sepals and petals each 3 (occasionally 4). Stamens 12-24. Leaves oval, peltate.
2. Nymphae'a. Sepals 4-6. Petals numerous, white. imbricated in many rows, gradually passing into stamens, hypogynous, or epi-gynous. Stamens epigynous. Stigmas radiating as in a Poppy-head.
3. Nu'phar. Sepals 5-6, yellow. Petals many, small and stamenlike. Stamens under the ovary.
B. peltata, Pursh. Stems and under surface of the leaves coated with jelly. Leaves oval, two inches across, peltate. Flowers small, purplish. - Ponds and slow-flowing streams.
1. N. odorata, Ait. (Sweet - scented Water-Lily.) Leaves orbicular, cleft at the base to the petiole, 5-9 inches wide, often crimson underneath. Flower very sweet-scented. Ponds and slow streams.
Var. minor, Sims, has much smaller leaves and flowers, and the latter are often pink-tinted.
2. N. tubero'sa, Paine. (Tuber-bearing W.) Leaves larger and more prominently ribbed than in No. 1, reni-form-orbicular, green on both sides. Flower not at all, or only slightly, sweet-scented. Root-stocks producing tubers, which come off spontaneously. - Mostly in slow waters opening into Lake Ontario.
1. N. ad'vena, Ait. (Common Y. P.) Leaves floating, or emersed and erect, thickish, roundish or oblong, cordate. Sepals 6. - Stagnant water. Var. minus is more slender, and has smaller leaves and flowers. Probably a hybrid between this and the next.
2. N. Kalmia'num, Ait. (Small Y. P.) (N.luteum,var. pumilum, Gray.) Floating leaves usually not more than two inches across, the sinus very narrow or closed; the radical ones very thin and with a wide obtuse sinus. Flowers hardly an inch across. Sepals 5. - Northward, in slow waters.