CERATOPHYLLACE^E. (HOKNWORT FAMILY.) 383 



(Name composed of (pa>p, a thief, and 8ev8pov, tree; because these plants steal 

 their food from the trees they grow upon.) 



1. P. flavesccns, Nutt. (American Mistletoe.) Leaves obovato 

 or oval, somewhat petioled, longer than the spikes in their axils, yellowish ; 

 berries white. (Viscum flavesccns, Pursh.) — New Jersey to Illinois and south- 

 ward, preferring Elms and Hickories. April. 



Order 98. SAURURACE^l. (Lizard's-tail Family.) 



Herbs, with jointed stems, alternate entire leaves ivith stipules, and perfect 

 flowers in spikes, entirely destitute of any floral envelopes, and 3-5 more or 

 less united ovaries. — Ovules few, orthotropous. Embryo heart-shaped, 

 minute, contained in a little sac at the apex of the albumen. — A kind of 

 offshoot of the Pepper Family (tropical), and represented only by 



1. SAURIJRUS, L. Lizard's-tail. 



Stamens mostly 6 or 7, hypogynous, with long and distinct filaments. Fruit 

 somewhat fleshy, wrinkled, of 3-4 pistils united at the base, with recurved 

 stigmas. Seeds usually solitary, ascending. — A perennial marsh herb, witli 

 heart-shaped petioled leaves, and white flowers, each from the axil of a small 

 bract, crowded in a slender wand-like and naked pcdunclcd terminal spike (its 

 appearance giving rise to the name, from aavpos, a li-ard, and ovpa, tail). 



1. S. ccrmius, L. — Margins of ponds, &c. ; common. June. — Spike 

 3' - 6' long, drooping at the end. 



Order 99. CERATOPHYLLACE.E. (Hornwort Fam.) 



Aquatic herbs, with luhorled finely dissected leaves, and minute axillary and 

 sessile monoecious flowers without any floral envelopes, but with an 8-12- 

 cleft involucre in place of a calyx, the fertile a simple 1-celled ovary, with a 

 suspended orthotropous ovule : seed filed oy a highly developed embryo with 

 4 cotyledons! and a conspicuous plumule. — Consists only of the genus 



1. CEBATOPHiLLirm, L. Hornwort. 



Sterile flowers of 12-24 stamens with large sessile anthers. Fruit an achc- 

 nium, beaked with the slender persistent style. — Herbs growing under water, in 

 ponds or slow-flowing streams : the sessile leaves cut into thrice-forked thread- 

 like rather rigid divisions. (Name from Kepas , a horn, and (pvXXov, leaf.) 



1. C. dcmersiliu, L. — Var. comm£jne has a smooth marginless fruit 

 beaked with a long persistent style, and with a short spine or tubercle at the 

 base on each side. — Var. eciiinatum (C. echinatum, Gray) has the fruit 

 mostly larger (3" long), rough-pimpled on the sides, the narrowly winged 

 margin spiny-toothed. — Slow streams and ponds ; common, but rare in fruit. 

 Probably there is only one species. (Eu.) 



