HIPPURIS.] HALORAGE^. 151 



ORDER XXX. HALORA'GE^E. 



Herbs or shrubs, often marsh, or aquatic, with much-reduced or imper- 

 fect perianths. Leaves opposite alternate or whorled, exstipulate. Flowers 

 often minute and 1-sexual. Calyx superior ; lobes 2, 4, or 0, valvate or 

 slightly imbricate in bud. Stamens 1-8, epigynous in the 2-sexual flowers, 

 filaments usually short ; anthers (except in Callitriche) long, 4-angled, 

 basifixed, slits lateral. Disk small or 0. Ovary inferior, mostly of 2 or 

 4 connate (rarely of 1) carpels ; styles or stigmas as many as the carpels, 

 2 in Callitriclie ; ovules 1 in each cell, pendulous, anatropous. Fruit 

 2-4-celled, indehiscent, or of 1-4 small 1-seeded drupes. Seed pendulous, 

 testa membranous, albumen fleshy ; embryo cylindric,. axile, or minute. 

 DISTRIB. Widely dispersed ; genera 9 ; species 80. AFFINITIES. Obscure, 

 probably near Saxtfragece and Ehizophorcce. PROPERTIES unimportant. 



Leaves all whorled, entire. Petals 1. Hippuris. 



Leaves all or lower whorled, much cut. Petals 2-4 2. Myriophyllum. 



Leaves all opposite, quite entire. Perianth 3. Callitriche. 



1. HIPPU'RIS, L. MARE'S-TAIL. 



Glabrous, aquatic herbs. Stems stout, erect, simple, leafy. Leaves 

 whorled, narrow, quite entire. Flowers minute, solitary, sessile, axillary, 

 sometimes 1-sexual. Calyx-tube subglobose, limb entire. Petals 0. 

 Stamen 1. Ovary 1 -celled ; style subulate, stigmatose throughout its 

 length. Drupe ovoid, stone crustaceous. Seed oblong, albumen scanty. 

 DISTRIB. Arctic and temp. N, hemisphere, Chili, Fuegia ; species 1 or 

 2. ETYM. 'linros and oi>pd, horsetail. 



H. vulg-a'ris, L. ; leaves 6-10 in a whorl linear acute. 



Margins of lakes, ponds, &c., from Shetland to Kent and Cornwall, local ; fl. 

 June-July. Rootstock submerged, stout, creeping. Stem 6-24 in., terete, 

 very many-jointed, as thick as a goose-quill or less ; rarely floating flaccid 

 and flowerless. Leaves |-1J in., close-set, tips withered. Flmvers green, 

 sessile. Anthers red. Drupe minute, smooth, green. DISTKIB. Of the 

 genus. 



2. MYRIOPHYL'LUM, L. WATER MlLFOIL. 



Glabrous marsh or aquatic herbs ; branches often floating. Leaves 

 opposite alternate or whorled. Flowers small, axillary, solitary or spiked, 

 anemophilous ; upper male, lower female, intermediate often 2-sexual. 

 MALE fl. Calyx 4- rarely 2-lobed or 0. Petals 2 or 4, concave. Stamens 

 2, 4, or 8. FEM. fl. Calyx-tube 4 -grooved ; lobes 4. minute or 0. Petals 

 minute or 0. Ovary 4- rarely 2-celled ; styles 4, very short, plumose. 

 Drupe deeply 2-4-lobed. Seeds oblong; albumen copious. DISTRIB. 

 Ubiquitous ; species 15. ETYM. pvpios and <pv\\oj>, from the finely-divided 

 leaves. 



