38 ALISMACEJE. [AI.ISMA. 



J-l in., and 2-5 slender erect 1 -flowered peduncles, 2-3 in., the upper- 

 most umbellate. Flowers i in. diam., white, claw of petals yellow. Jti./ir- 

 carpels beaked. DISTRIB. Europe N. of the Alps and Spain. 



2. ACTINOCAR'PUS, Br. STAK-FRUIT. 



Habit and inflorescence of Alisma, but carpels 6-8, connate at the base, 

 spreading horizontally, 2-ovuled. Fruit of as many stellately spreading 

 1-2-seeded long-beaked carpels. Seeds, lower erect, upper horizontal, testa 

 membranous rugose; embryo hooked. DISTRIB. Europe, California, 

 Australia ; species 3. ETYM. dutriv and Kapiros, from the rayed fruit. 



1. A. Damasonium, Br. ; leaves narrow oblong 3-5-nerved, base cor- 

 date. Damasonium stcllatum, Pers. 

 Gravelly ditches and pools, rare ; southern counties from Salop and Suffolk 



to Sussex and Hants; fl. May-July. leaves many, 2 in., obtuse, floating 1 



or emersed ; petioles stout, 2-5 in. Scape 4-6 in., stout, with usually 2 



whorls of flowers ; pedicels 1 in. Flowers $ in. diam. ; petals caducous. 



Fruit % in. diam., carpels dehiscing ventrally. DiSTUlB. France, Spain, 



Italy, Dalmatia, Mid. Russia, N. Africa. 



3. SAGITTA'RIA, L. 



Habit and inflorescence of Alisma, but flowers usually 1 -sexual ; 



stamens numerous ; anthers basifixed, dehiscence lateral. DISTRIB. Temp. 



and trop. ; species about 15. ETYM. sagitta, an arrow. 



1. S. sagittifo'lia, L. ; leaves hastate obtuse or acute. Arrow-head. 



Ditches, canals, &c. from Durham to Kent and Devon ; naturalized in Scot- 

 land, rare and local in Ireland ; fl. July-Sept. Stem swollen at the base, 

 stoloniferous. Leaves 2-8 in., erect, lobes long, more or less diverging, 

 acuminate, the first developed submerged, pellucid, linear ; petiole 8-18 in., 

 stout, 3-gonous. Scape 6-18 in., with 3-5 distant whorls of 3-5 flowers 

 each ; bracts short, obtuse, membranous ; lower whorls female, pedicel short ; 

 upper male with longer pedicels. Flowers in. diam., males larger. 1'itnh 

 white, caducous, claw, purple. Anthers purple. Advenes numerous, much 

 compressed laterally, broadly obliquely obovate, apiculate, wings broad 

 thick, cell small. Seed as in A lisma. DISTRIB. Europe (Arctic), N. Asia, 

 N.W. India. 



4. TRIG'LOCHIN, L. ARROW-GRASS. 



Root fibrous. Leaves erect, very narrow, flat or 4 -terete. Flowers 

 racemed, small, green, ebracteate. Perianth-segments 6, all similar, 

 cucullate, subequal, deciduous. Stamens 6, on the base of the perianth- 

 segments, filaments very short ; anthers broad, bursting outwards. Ovary 

 6-celled ; stigmas 3 or 6, feathery ; ovules one in each cell or the alternate 

 cells empty, anatmpous. Fruit of 3-6 1-scedcd coriaceous carpels, sepa- 

 rating from a central axis and dehiscing in front. Seeds erect, terete, testa 

 coriaceous. DISTRIB. Temp, regions, many Australian ; species about 10. 

 ETYM. T/>?S and y\^x' iv > fr m tne 3 pointed carpels. 



1. T. palus'tre, L. ; leaves filiform, ^-terete throughout, fruit clavate, 

 carpels 3 slender long attached to the receptacle by a point. 

 Marshes and wet meadows; ascends to 2,000 ft. in the Highlands ; fl. June- 



Aug. Stem slightly swollen at the base, stoloniferous. Leaves 2-12 in., 



