ALISMA. | ALISMACE. 307 
Dehra Dun (Parker) common, usually associated with Lemna pauci- 
costata appearing earlier but ultimately replaced by Lemna. Flowers 
September. Duisrrrp,: Punjab, Bengal. 
CXIX.—ALISMACEZ. 
Aquatic or marsh herbs, usually erect. Leaves radical or clus- 
tered at the nodes of floating stems, entire, petioled, sometimes 
pellucid-dotted or lineolate. Flowers pedicelled, 1- or 2-sexual ar 
polygamous, rarely dicecious, arranged in umbelled or panicled 
whorls, usually white or pink; bracts 3 or more, membranous, 
bracteoles small. Perianth-segments 6, in 2 series; outer 3 
herbaceous; inner petaloid, rarely absent. Stamens 6 or more, 
rarely 3, hypogynous or perigynous; anthers erect, basifixed, 
2-celled, dehiscence by lateral or dorsal slits. Carpels 3-6 or more, 
free, l-celled, sessile or stipitate on a flat or raised receptacle ; 
style short or long, rarely none, subterminal or ventral, stigma 
simple; ovules ] or more in each carpel, placentas on the inner 
angle or with a solitary basilar ovule. Fruit of small achenes or 
follicles, Seeds small or minute, exalbuminous, embryo straight 
or conduplicate.—Species about 60, in temperate and tropical 
regions. 
Fruit indehiscent, of 3 or more achenes ; ovules 
and seeds solitary :— 
Stamens few, 6-9; receptacle flat; flowers 
2-sex . ‘ ; ? ‘ : . I. ALISMA. 
Stamens usually many, rarely as few as 6; 
receptacle globose or qplong:; flowers 
l-sex or polygamous. ° . 2, SAGITTARIA, 
Fruit dehiscent, of 6-7 follicles ; stamens 8-12 ; 
fis. 2-sexual ; ovules and seeds many . 3. Buromopsis 
1,‘ ALISMA, Linn.; Fi. Brit. Ind. vi, 559% 
Scapigerous stemless palustrine perennial herbs. Leaves lanceo- 
late, cordate or sagittate. Flowers 2-sexual, in umbelled or 
panicled whorls, white or pink, Sepals 3, herbaceous yersistent. 
