6 BIOLOGICAL CLASSIFICATION [CH. 



(ii) Plants in which the floating type of leaf is generally 

 associated with the flowering stage. 



E.g., Nymphaea lutea, L. (Yellow Waterlily). 

 Castalia alba, Greene (White Waterlily). 

 Various Batrachian Ranunculi (Water Butter- 

 cups). 



Callitriche verna, L. (Water Starwort). 

 Potamogeton natans, L. (Pondweed). 



D. Plants which may, in certain cases, occur as land forms, 

 but are normally submerged and are characterised by a creep- 

 ing axis bearing long, branching, leafy shoots with no floating 

 leaves, or by a plexus of leafy, rooting shoots without a creeping 

 rhizome. 



(i) Leafy aerial shoots produced at the flowering period. 

 E.g., Myriophyllum verticillatum, L. (Water Mil- 

 foil). 

 Hippuris vulgaris, L. (Mare's-tail). 



(ii) Inflorescence raised out of the water, but no aerial 

 foliage leaves except in the land forms. 



E.g., Myriophyllum (except M. verticillatum) (Water 



Milfoil). 



Hottonia palustris, L. (Water Violet). 

 Many Potamogetons (Pondweeds). 



(iii) Inflorescence submerged, but essential organs raised 

 to the surface. 



E.g., Elodea canadensis, Michx. (Water Thyme). 



(iv) Inflorescence entirely submerged and pollination 

 hydrophilous. 

 E.g., Naias. 



Zannichellia (Horned Pondweed). 



Zoster a (Grass- wrack). 



Callitriche autumnalis, L. (Water Starwort). 



Halophila. 



