129. ALISMACEjE. [1. Alisma. 



CLASS— MONOCOTYLEDONES. 



FAM. 129. ALISMACE^. 



Marsh or water plants supplied with laticiferous vessels, usually 

 with a thickened rhizome. Leaves radical, floating or aerial, pal- 

 mately nerved or nerves parallel. Flowers regular, 1-2-sexuaU 

 mostly verticillate in branched radical inflorescences. Calyx and 

 corolla distinct, each of 3 members or corolla 0. Stamens 6-many, 

 hypogynous or perigynous, anthers erect basifixed, 2-celled, extrorse 

 or (Buiuiiiece) introrse. Carpels 3-6 or more, 1-celled, free, some- 

 times stipitate, styles and stigma simple. Ovules 1, 2 or many in 

 each carpel, anatropous with 2 integuments. Fruit of achenes or 

 follicles. Seeds small, exalbuminous. Embryo straight or con- 

 duplicate. 



I. Ovules solitary, basilar. Fruit of achenes :— 



Fls. 2-.sexual. St. 0-9. Receptacle Hat I. Aliama. 



Fls. polvgamous. St. G. Receptacle flat 2. Linuwphj/fon. 



Fls. 1-sexual. St. many. Receptacle elevated . . . 3. Sagittaria. 



II. Ovules several on the inner wall. Fr. foUicular:— 



Stamens 8-12 . i. Bntomoii^h. 



1. ALISMA, L. 



Scapigerous herbs with lanceolate, cordate or sagittate leaves and 

 delicate white or pink 2-sexual flowers arranged in branched whorls 

 on a pyramidal panicle. Sepals 3 persistent. Petals 3 deciduous. 

 Stamens 6 or 9. Carpels few to many on a small flat receptacle. 

 Ovule solitary, basilar in each carpel. Fruit of coriaceous or hard 

 achenes. Seed erect Avith membranous testa and horseshoe-shaped 

 embryo. 

 I. Leaves always lonc^er than broail, rarely siilicordate, 5-7- 



nerved . ' 1- iJlanfcif/o. 



II. Leaves sometimes broader than lony, cordate, over 10-nerved : — 



Leaves coriaceous, rounded. Style slender persistent . . 2. reniforme. 

 Leaves membranous, acutely lobed. Style very short de- 

 ciduous . . . .' 3. oii,'/oeocci(m. 



1. A. plantago, L. 



A large marsh herb 1-4 feet high with the panicle. Leaves 0-8" 

 erect or spreading, mostly lanceolate or ovate-lanceolate 5-7-nerved, 

 but vai'ying to linear or subcordate. Flowers •3--4" diam. very 

 delicate, in panicled whorls. Achenes numerous, over 20, membranous, 

 compressed ; style slender, deciduous. 



Marshes and ponds. Toward^^ the Nepal boundary from Bettiah to Purneah. 

 Fl. c.s. Annual in our area ! and never attaining the dimensions of the English 

 plant. 



2. A. reniforme, Don. 



Habit of A. jAantago, with an annual stem and 13-15-nerved 

 orbicular-ovate leaves 2-o" by 2" to 4-5" long by G-5" wide (broader 

 than long), with rounded or refuse tip. Flowering stems 12-30", 

 branches 3-4 or usually 6 in a whorl with bracts up to -5" long in the 

 lowest whorls. Flowers white or pink-purple, -5" diam. J^'ruiting 



843 



