ALISMA.] ALISMACEsE. 367 



next the hilum. DISTRIB. All climates ; genera 10 ; species about 50. 

 AFFINITIES. With Naiadece. PROPERTIES unimportant. 

 TRIBE I. ALIS ME-ffi. Leaf-blade flat. Petals large, fugacious. Stamens 6 

 or more. Ovules 1-3, campylotropous. Embryo sharply curved. 



Flowers 2-sexual, hexandrous. Carpels free 1. Alisma. 



Flowers hexandrous. Carpels connate, spreading 2. Actinocarpus. 



Flowers 1-sexual, polyandrous. Carpels free 3. Sagittaria. 



TRIBE II. JUNCAGI'NE-ffl. Leaves linear or filiform. Petals small, green. 

 Stamens 6. Ovules 1-3, anatropous. Embryo straight. 



Anthers short. Carpels united till mature 4. Triglochin. 



Anthers long. Carpels free 5. Scheuchzeria. 



TRIE III. BU'TOMEJE. Leaves 3-quetrous. Petals and sepals similar, 

 pink. Ovules many, anatropous. Embryo straight 6. Butomus. 



1. ALIS'MA, L. 



Roots fibrous. Leaves erect or floating. Inflorescence umbelled or 

 panicled, branches whorled, bracteate. Sepals herbaceous. Petals deci- 

 duous, membranous, involute in bud. Stamens 6, filaments filiform ; 

 anthers versatile, dehiscence inwards. Carpels many, free ; style ventral 

 or terminal, short, stigma simple ; ovules solitary, erect, campylotropous. 

 Achenes turgid or compressed, ribbed, keeled or grooved, dehiscing or not. 

 Seed erect, testa very thin ; embryo hooked. DISTRIB. Temp, and trop. ; 

 species 20. ETYM. Doubtful. 



1. A. Planta'go, L. ; leaves erect, flowers panicled, carpels in one 

 whorl laterally compressed, styles ventral. Water Plantain. 



Ditches and edges of rivers, &c. from Ross southwards ; rare in the N. of 

 Scotland; fl. June- Aug. Base of stem swollen, fleshy. Leaves 6-8 in., 

 petioled, ovate-lanceolate, acute obtuse or subcordate at the base, 5-7- 

 ribbed, young submerged or floating. Scape 1-3 ft. ; pedicels 1-1J in. 

 Flowers % in. diam. Petals pink or rose, claw yellow. Carpels 20-30. 

 DISTRIB. Arctic and N. temp, regions, Himalaya, Australia. Juice acrid. 



VAR. 1, Planta'go proper ; leaves subcordate, sepals oblong, styles twice as 

 long as the ovary. VAR. 2, lanceola'tum, With, (sp.) ; leaves lanceolate, 

 sepals ovate, styles as long as the ovary. 



2. A. ranunculoi des, L. ; leaves erect linear-lanceolate, flowers um- 

 belled or whorled, carpels capitate 4-5-ribbed turgid, styles terminal. 

 Bogs and ditches, from Ross southwards ; fl. May-Sept. Tufted. Leaves 



petioled, blade 2-3 in., 3-ribbed ; the first developed submerged, pellucid, 

 sometimes floating. Scape 6-18 in.; pedicel 1-3 in. Flowers as in A. 

 Plantago. Ripe carpels ovoid, apiculate. DISTRIB. Europe from Gothland 

 southwards except Turkey, N. Africa. 



VAR. 1, ranunculoi' des proper ; erect or suberect. VAR. 2, re'pens, Davies 

 (sp.) ; scape procumbent geniculate rooting. Lakes, N. Wales and Ireland. 



3. A. na'tans, L. ; radical leaves submerged, cauline floating, flowers 

 few, carpels capitate turgid many-ribbed, styles terminal. 



Lakes, very rare, N. and W. of England, from York to Hereford and Wales ; 

 near Stranraer in Scotland ; W. of Ireland, rare and local ; fl. July-Aug. 

 RtulifMl leaves 2-8 in., submerged, subulate-lanceolate, pellucid. Stem 

 floating and rooting, giving off long-petioled, oblong, floating leaves, 



