APETALOUS EXOGENOUS PLANTS. 477 



P. FLAVESCENS, Nutt. (Viscum flavesccns, Pursh.) 

 April and May. Plant yellowish, 2°-3° long; hranchcs 

 opposite or wliorled; leaves obovate, fleshy; cS/Ji to shorter 

 than tlie leaves ; lerry white, glutinous. 



107. LIZARD'S- TAIL FAMILY. Order, Saururace^. 



Perennial marsh lierls, with jointed stems, alternate en- 

 tire leaves, with sheathing stipules, and perfect floivers in 

 bracted spikes or racemes ; calyx and corolla none ; stamens 

 few or many, hypogynous ; anthers introrse, opening length- 

 wise ; ovaries 3-5, more or less united ; ovules few, ortho- 

 tropous, ascending; embryo minute, cordate, contained in 

 a cavity at the apex of the albumen ; fruit follicular, 1-few- 

 seeded. 



SAURURUS, L. Lizard's-tail. 



Stainens 4-8, with long club-shaped filaments; fruit 

 somewhat fleshy, composed of 3-4 partly united 1-2-seeded 

 carpels, pointed with as many stigmas ; flowers white. 



S. CERNLTDS, L. Stem erect, branching ; leaves petioled, 

 cordate-ovate, or oblong-ovate, acuminate; spikes white, 

 terminal, nodding at the apex; flowers numerous, each 

 from the axil of a small bract. Marshes and muddy banks. 

 May-August. Bhizoma creeping; stem l°-2° high; spikes 

 4'-6' long. 



lOS.HORN'WORT FAMILY. Or^er, Ceratophyllace^. 



Submerged aquatic herbs, with filiform jointed and 

 branching stems, finely dissected whorled leaves, and small 

 axillary monoecious floivers, destitute of floral envelopes, 

 but surrounded by an involucre of 8-12 linear leaves; 

 anthers 12-24, oblong, 2-3-toothed, sessile ; ovary solitary, 

 simple, w^th a single suspended orthotropous ovule ; ache- 

 niiini compressed, pointed with the slender persistent style ; 

 albumen none; cotyledons 4; j[;?w?m^/e conspicuous. Con- 

 sisting of the single genus 



