72 ELEMENTS OF BOTANY. 



37. NYMPH^ACEiE. WATER-LILY FAMILY. 



Perennial aquatic herbs ; rootstocks creeping in mud ; leaves 

 entire, peltate or cordate, usually floating on the surface of 

 the water ; flowers solitary on long peduncles ; sepals 3-5 ; 

 petals 5-raany ; ovary 1, many-celled ; seeds often enclosed 

 in a pulpy aril. 



I. NYMPHiEA. 



Rootstock horizontal, thick, cylindrical ; leaves cordate, 

 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, seeds without an aril. 



N. ADVENA Sol. Y"ellow Pond Lily. Leaves oval or orbicu- 

 lar, rather thick, often pubescent beneath ; flowers bright yellow, 2- 

 3 in. in diameter, depressed-globose ; sepals 6 ; petals thick and 

 fleshy, truncate ; stamens in several rows, anthers nearly as long as 

 the filaments. April-September. In slow streams and still water. 



IL CASTALIA. 



Rootstock horizontal, creeping extensively ; leaves floating, 

 entire, peltate or cordate ; flowers showy ; sepals 4, green 

 without, white within ; petals many, white, becoming smaller 

 toward the center ; stamens many, the outer with broad and 

 the inner with linear filaments ; ovary many-celled, stigmas 

 peltate and radiating ; fruit baccate, many-seeded. 



C. ODORATA (Dryand) W. & W. White Water-lily. Root- 

 stock large, branched but little ; leaves floating, entire, the sinus 

 narrow and basal lobes acute, green and smooth above, purple and 

 pubescent beneath ; petioles and peduncles slender ; flowers white, 

 very fragrant, opening in the morning, 3-5 in. broad ; fruit globose, 

 seeds enclosed in a membranaceous aril. May-July. In ponds and 

 still water. 



