14 
Leaves stalked, or narrowed at the base. 
Leaves blunt; calyx present; corolla with little teeth 
[ within, between its lobes. , 
Sam’olus Valeran'di. Brookweed/ 
\Leav es pointed ; flowers without any green calyx. ») 
t Polyg’onum. ) 
Leaves without stalks, narrow, or rush-like. 
Leaves thick and opaque, or rush-like and hollow. 
§ _Leaves thick, but flat and ribbon-shaped; flowers 
| rudimentary, in rounded heads. 
| Sparganium. S#ur-reed. 
' “Leaves cylindrical, hollow, with cross-partitions 
inside; flowers with 6 segments. 7 
[ Juncus articula'tus. ‘Fointed Rake 
~Leaves thin, showing a mid-rib, or threadlike. 
Flowers ina spike; upper leaves thread-like, com- 
posed of a double tube. } 
| Potamoge'ton. fPondweed. 
\Flowers not in a spike; leaves thin, flat. 
Leaves almost thread-like ; flowers on separate ~ 
i stalks. J 
Rup’pia maritima. 
~Leaves ribbon-like ; flowers enclosed in a sheath 
at their base. } 
Zoste'ra. 
Sect. D. FLOWER-PARTS IN THREES 
OR SIXES. 
Leaves opposite. 
Leaves toothed; flowers with only 3 greenish seg-~ 
f ments. 
| Mercuria is. Mercury/ 
“Leaves entire. 
Flowers with both calyx and corolla. 
Petals very narrow and fine-pointed; stamens~ 
@ ly. 
«ee : J 
q Tille’a musco'sa. 
Petals bluntish, rose-coloured; flowers with 6 
stamens. ) 
Blat‘ine hexan’dra. Waterwort. 
~Flowers without corolla; calyx with 6 teeth, and 
6 smaller ones between them. 
L Pep'lis Por'tula. Water Purslane. 
Leaves not opposite. 
a al, 
