CALLITKICHACEiE. ( WATER-STAR W GETS.) 427 



Order 93. SAUBURACEiE. (Lizahd's-tail Family.) 



Herbs, with jointed stems, alternate entire leaves, and perfect flowers in 

 spikes, entirely destitute of any floral envelopes, and with 3-5 more or less 

 separate or united ovaries. — Ovules few, orthotropous. Embryo heart- 

 shaped, minute, contained in a little sac at the apex of the albumen. — An 

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



1. SAURUEUS, L. Lizajrd's-iah.. 



Stamens mostly 6 or 7, hyjjogynous, with distinct filaments. Fruit somewhat 

 fleshy, wrinkled, of 3 - 4 pistils united at the base. Stigmas recurved. Seeds 

 usually solitary, ascending. — Perennial marsh herbs, with heart-shaped con- 

 verging-ribbed petioled leaves, without distinct stipules ; flowers (each with a 

 small bract) crowded in a slender wand-like and naked peduncled terminal 

 spike or raceme (its appearance giving rise to the name, from travpos, a lizard 

 and ovpn, tail). Bract adnate to or borne on the pedicel. 



1. S. o6rnuus, L. Flowers white, in a dense spike nodding at the end; 

 bract lanceolate ; filaments long and capillary. — Swamps : common. June - 

 Aug. 



Order 94. CERATOPHYLLACEjE. (Hornwort Family.) 



A quatic herbs, with whorled flnely dissected leaves, and minute axillary 

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

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

 suspended orthotropous ovule : seed filled by a highly developed embryo with 4 

 cotyledons ! and a conspicuous plumule Consists only of the genus 



1. CEBATOPHYLLUM, L. Hoenwoet. 



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

 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 rigid divisions (whence the name from Kipas, a horn, and cj>iWov, leaf). 



1. C. d^mersum, L. — Var. cOMMtaE 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. ECHiNiTUM (C. cchinatum. Gray) has the fruit 

 mostly larger (3" long), i-ough-pimpled on the sides, the narrowly winged mar- 

 gin spiny-toothed. — Slow streams and ponds : common, but rarely seen in fruit. 

 Probably there is only one species. (Eu.) 



Order 95. CALLITRICHACE^E. (Water-Stakworts.) 



Small annuals or perennials, mostly aquatics, ivith opposite entire leaves 

 and axillary monoecious flowers without any proper floral envelopes, and with 

 a 4-lobed and i-celled i-seeded fruit ; ^ consisting only of the genus Calll- 

 triche (regarded by many botanists, perhaps with good reason, as repra- 



