PIPER — FLORA OF THE ;5TATE OF WASHINGTON. 265 



{Nuphar jwlysepalum pidum Engelm.) are of frequent occurrence. Nymphaea advena has 

 several times been reported from Washington, but it is improbable that that species occurs 

 so far west, the above being mistaken for it. 



CERATOPHYLLACEAE. 



CERATOPHYLLUM. 



1. Ceratophyllum demersum L. Sp. PI. 2: 992. 1753. Hornwort. 



Type locality: Europe. 



Range: Temperate North America. Europe. 



Specimens examined: Lake Washington, Piper, July 12, 1895. 



This plant is common in lakes, but is rarely collected. Fruiting specimens are very 

 rare. Good material is a desideratum, as there is some probability that more than one 

 species occurs in Washington. 



RANTJNCULACEAE. Buttercup Family. 



Carpels with solitary ovules; fruit an akene. 



Sepals valvate in the bud; leaves opposite Clematis (p. 266). 



Sepals imbricated in the bud; leaves not opposite. 

 Cauline leaves three in a whorl. 



Styles short, glabrous or pubescent Anemone (p. 267). 



Styles long, plumose Pulsatilla (p. 268). 



Cauline leaves alternate or leaves all basal. • 



Petals none; flowers small, numerous in corymbs or 



panicles. Leaves ternately decompound Tiialictrum (p. 268). 



Leaves simple, palmate Trautvetteria ( p. 269). 



Petals present. 



Akenes numerous on an elongate receptacle; 

 "■ flowers solitary on scapes ; leaves entire . . . Myosurus ( p. 269 ) . 



Akenes in a globose or oblong cluster. 



Flowers white; akenes transversely wrin- 

 kled Batrachium (p. 270). 



Flowers yellow; akenes not transversely 



wrinkled Ranunculus (p. 270). 



Carpels with several ovules, in fruit follicles or berries. 

 Flowers regular. 



Leaves simple, palmate. 



Petals none; leaves cordate-orbicular Caltha (p. 277). 



Petals linear-spatulate ; leaves palmately parted . . Trollius (p. 277). 

 Leaves compound. 



Sepals spurred Aquilegia (p. 278). 



Sepals not spurred. 



Petals large ; sepals persistent ; flowers solitary . Paeonia (p. 278). 

 Petals small; sepals deciduous. 



Carpels becoming berries; flowers in 



Racemes Actaea (p. 278). 



Carpels becoming follicles. 



Follicles stipitate; flowers solitary or 

 umbellate ; leaves coriaceous, ever- 

 green CoPTis (p. 278). 



Follicles sessile; flowers racemose; 



leaves membranous, deciduous. . . Cimicifuga (p. 278). 

 Flowers irregular. 



Upper sepal spurred ; petals 4 Delphinium (p. 279). 



Upper sepal hood-like; petals 2 Aconitum (p. 282). 



