82 KEY AND FLORA 
32. NYMPHZACEZ. Water Lity Famity 
Perennial aquatic herbs. Leaves usually floating, often shield- 
shaped. Flowers borne on naked scapes. Floral envelopes and 
stamens all hypogynous or epigynous. Sepals 3-6. Petals 
3-5 or often very numerous. Stamens many. Carpels 3 or 
more, free or united. Fruit a berry or a group of separate 
carpels. 
I. NYMPHAEA L. 
Rootstock horizontal, thick, cylindrical. Leaves heart-shaped, 
floating or erect. Flowers yellow. Sepals 4-6, green on the 
outside, obovate, concave. Petals many, hypogynous, the 
inner ones becoming small and stamen-like. Stamens many, 
hypogynous. Ovary cylindrical, many-celled; stigma disk- 
shaped. Fruit ovoid.* 
1. N. advena Ait. YELLow Ponp Liry, Cow Lity, SpaTTer- 
Dock. Leaves oval or orbicular, rather thick, often dowuy beneath. 
Flowers bright yellow, 2-3 in. in diameter, depressed-globular. 
Sepals 6. Petals thick and fleshy, truncate. Stamens in several 
rows; anthers nearly as long as the filaments. In slow streams and 
still water.* 
Il. CASTALIA Salisb. 
Rootstock horizontal, creeping extensively. Leaves float- 
ing, entire, shield-shaped or heart-shaped. Flowers showy. 
Sepals 4, green without, white within. Petals many, white, 
becoming smaller towards the center. Stamens many, the 
outer with. broad and the inner with linear filaments. Ovary 
many-celled, stigmas shield-shaped and radiating. Fruit berry- 
like, many-seeded.* 
1. C. odorata Woodville and Wood. Wuite Warer Lity. Root- 
stock large, branched but little. Leaves floating, entire, the notch 
narrow and basal lobes acute, green and smooth above, purple and 
downy beneath. Petioles and peduncles slender. Flowers white, very 
fragrant, opening in the morning, 3-5 in. broad. Fruit globose; seeds 
inclosed in a membranaceous sac. In ponds and still water.* 
2. C. tuberosa Greene. Much like No. 1. Rootstock bearing loosely 
attached, often compound tubers, Leaves round-kidney-shaped, sel- 
dom purple beneath. Flowers larger than in No. 1, scentless or nearly 
so. Slow streams, especially W. 
