XYMPIIAEACEAE. 16o 



involucre. Staminate flower consisting of numerous stamens crowded on the 

 receptacle; anthers sessile. Pistillate flower consisting of one pistil; ovary 

 superior, 1 -celled, with a single ovule. Fruit indehiscent, beaked by the 

 slender persistent style, spinose or tuberculate at base. Embryo with highly 

 developed plumule. No endosperm. 



1. CERATOPHYLLUM L. 



The only genus. (Greek keras, a horn, and phullon, a leaf, the leaves cut 

 into slender rigid divisions.) 



1. C. demersum L. Horn wort. Stems slender, y 2 to 2 ft. long; leaves in 

 whorls of 6 to 8, the segments prickly-dentate, ^ to 1 in. long ; style as long 

 as the aehene; this 1 to 2 lines long, with a spine or reflexed horn on each 

 side near the base. 



Ponds and lakes: Santa Cruz, San Francisco, and northward. Throughout 

 North America and in Europe. Aug. Seldom collected in fruit; aehene vari- 

 able, the margin winged or wingless and the sides sometimes crested or cov- 

 ered with tubercles. 



NYMPHAEACEAE. Water-lily Family. 



Aquatic perennial herbs with horizontal rootstocks or with tubers. Leaves 

 floating or erect, peltate or deeply cordate. Flowers large, solitary, complete, 

 on long peduncles. Sepals 3 to 12. Petals 3 to many. Stamens 6 to numer- 

 ous. Carpels 3 to many, superior, united into a single pistil with many 

 cells, or distinct. 



Petals many; pistil 1, compound 1. Xymphaea. 



Petals 3 or 4; pistils several, distinct 2. JJrasenia. 



1. NYMPHAEA L. Poxd Lily. 

 Aquatic or subterrestial plants. Scapes from creeping rootstocks rooting 

 from beneath and bearing on the upper side the scars of former petioles. 

 Leaves in ours cordate with rounded lobes and narrow or closed sinus; peti- 

 oles long. Sepals 5 to 12, conspicuous, orbicular, concave, mostly petal-like, 

 unless at base or on the outside. Petals 10 to 20, small and thick, bearing 

 more or less resemblance to staminodia. Stamens hypogynous, numerous, 

 densely imbricated around the ovary, at length recurving ; anthers linear ; 

 filaments very short. Ovary 1m to 25-celled, the stigmas radiating upon its 

 truncate or disk-like summit. Fruit coriaceous-baccate. (Latin name of the 

 water-lily. Fl. June- Aug.) 



Sepals 6 to 7; anthers yellow: stigmatic rays 13 to 22 1. N. advena. 



Sepals 5 to 12; anthers dark red; stigmatic rays 15 to 24 2..N. polysepalum. 



1. N. advena Ait. Cow Lily. Rootstock horizontal, creeping; leaves 6 

 to 9y 2 in. broad, 9 to 13 in. long, floating or raised above the water on stout 

 subterete petioles; calyx \y A (when fully expanded. 2 to 3) in. in diameter; 

 sepals 6 or 7, the inner narrowed at base, yellow, the three outer smaller and 

 greenish; petals about 15, nearly or quite concealed beneath the many 

 stamens; stamens in 5 or 6 series; anthers yellow; stigmatic rays 13 to 15 

 or 22, usually not reaching the edge of the disk; neck beneath the disk 

 scarcely constricted. — (Nuphar advena Soland.) 



Lakes and sloughs: Stockton; far northward and eastward. 



2. N. polysepalum Greene. Indian Pcnd Lilt. Leaves ;i- in the pre- 

 ceding, the sinus 1/3 to y 2 the length of the blade; calyx subglobose or some- 

 what cup-shaped, 3 (or when fully expanded 4 to ')) in. in diameter; sepals 



