454 Ceratophyllaceae Ceratophyilum 



89. CERATOPHYLLACEAE Gray 

 2516. CERATOPHYLLUM L. 



1. Ceratophyllum demersum L. HORNWORT. Map 933. Common in 

 most of the lakes of the lake region, becoming infrequent to rare in streams 

 and ponds south of the lake region. 



Throughout N. A. except the extreme north. 



91. RANUNCULACEAE Juss. Crowfoot Family 



Plants climbing; flowers white, maroon, or purple; leaves mostly compound 



2542. Clematis, p. 463. 



Plants not as above. 

 Leaves 3- or 4-ternate; plants dioecious; pistillate flowers white; staminate flowers 



greenish, whitish or purplish; fruit an achene 2548. Thalictrum, p. 473. 



Leaves not as above ; plants not dioecious. 



Ovaries several-ovuled (1 or 2 in Hydrastis) ; fruit a follicle which sometimes 

 resembles a berry; calyx generally petaloid. 

 Flowers regular, white, scarlet or yellow. 



Leaves simple, either palmately lobed or divided, reniform or cordate. 



flowers white, small, about 1 cm wide; leaves palmately 5-7-lobed; roots 



yellow ; fruit red 2522. Hydrastis, p. 455. 



Flowers bright yellow or greenish yellow, large, generally 2-3 cm wide. 



Flowers bright yellow; leaves not divided; plants of springy places 



2524. Caltha, p. 455. 



Flowers greenish yellow; leaves divided into 7-11 lobes; plants introduced. 



2527. Helleborus, p. 456. 



Leaves ternately decompound. 



Plants low, generally less than 30 cm high. 



Leaves basal and cauline, the basal ones biternate, the cauline ones ter- 

 nate, alternate; flowers cauline, several axillary and terminal, the 

 floral parts 5; roots fibrous. (Our species of this genus is often 

 confused with Anemonella thalictroides. The roots of Anemonella are 

 tuberous; cauline leaves in a terminal whorl; and floral parts more 



than 5.) 2532. Isopyrum, p. 456. 



Leaves all basal and ternate; 1-flowered, flowers on scapes 



2534. COPTIS, p. 456. 



Plants tall, usually 0.5-2 m high. 



Flowers in terminal racemes, small, white. 



Racemes simple, generally less than 5 cm long; fruit red or white, 



fleshy, several-seeded, resembling a berry 2537. Actaea, p. 457. 



Racemes generally paniculate, usually 2-4 dm long; fruit many-seeded 



follicles 2537A. Cimictfuga, p. 457. 



Flowers not in racemes, large, showy; petals spurred, scarlet 



2538. Aquilegia, p. 458. 



Flowers irregular, blue or pinkish, except albino forms. 



Posterior sepal prolonged into a spur generally 10-15 mm long 



2539. Delphinium, p. 458. 



Posterior sepal hooded, covering the 2 petals 2540. Aconitum, p. 459. 



Ovaries 1-ovuled; fruit an achene. 

 Leaves all radical; flowers on scapes. 



Leaves reniform, 3-lobed; scape 1-flowered 2541 B. Hepatica, p. 462. 



Leaves linear; scape 1-flowered, the greatly elongated receptacle resembling 

 a many-flowered spike 2543. Myosurus, p. 464. 



