13 
Leaves (mostly) opposite. 
Leaves thread-like, fine-pointed. 
Leaves finely toothed along the margin; (rare plants, 
of Norfolk and Lancs.). 
Na‘ias.7 
Leaves not toothed; fruits projecting in the angles 
of the leaves. } 
L Zanichel'lia palus'tris. 
Leaves not thread-like. : 
Stem often long and slender; flowers minute, without 
f calyx or corolla. | 
L Callit'riche aquatiica./ 
Stem short; flowers with (at least) a calyx. 
Calyx with 6 or 12 short teeth; petals minute, 
[ often absent. } 
q Pep'lis Por'tula. Water Purslane. 
Calyx deeply divided. 
Calyx with 2 segments only; corolla 5-lobed ; 097 
plant often in dense tufts. ; a 
‘~Mon’'tia fonta’‘na. inks. 
Calyx and corolla each with 3 or 4 segments; 
plant creeping. } “e 
Elat'ine. Water Pepper 
EL eaves not opposite. 
Leaves all springing from the root. 
Leaves strongly toothed at margin; corolla of 3 white Y , 
petals. — } 
Stratio'tes aloides. Water-soldier. 
Leaves not toothed. 
Leaves stalked or narrowed at their base; corolla 
f 5-lobed. . : } 
L Limosel'la aquatica. I/udwort. 
Leaves quite without stalks. 
Leaves (formed of 2 tubes) flattened and blunt (Cs fy” 
[ at apex; flowers irregular. j 7N &Y 
q Lobe'lia Dortman’na. 
Leaves cylindrical and tapering at apex; corolla y 
regular. 
Corolla membranous, in one piece, 3- or Va 
4-cleft. } 
Littorella lacus'tris. Shore-weed. 
Flowers with 4 separate and distinct petals, 
not membranous. } 
L Subularia aquatica. <Aw/wort. 
Stem bearing leaves. 
