A GUIDE AND KEY TO AQUATIC PLANTS 



47 



KEY TO GROUP F 

 1. Leaves simple 2. 



1. Leaves, or some of them, compound or at least cut 4. 

 into narrow segments almost to the midrib. 



2. Leaves deeply lobed other than at base of 16. 



blade. 

 2, Leaves not deeply lobed except sometimes at 3. 

 base of blade. 

 3. Leaves definitely lobed at base of blade; that is, lobes 20. 

 extending below the junction of the petiole and the 

 leaf. 

 3. Leaves not lobed but sometimes sessile and clasping 30. 

 at the base. 



4. Leaves fern-like; plant not bearing flowers 5. 



4. Leaves not fern-like; plants bearing flowers.- 6. 

 5. Spores borne in sacs on lower leaf surface; divisions of Anchistea, p. 67. 



the leaf small, less than 2 cm. long (fig. 1) . 

 5. Spores borne on terminal modified leaves; divisions of Osmunda, p. 67. 

 the leaf larger, more than 2 cm. long (fig. 2) . 



FiQUKE 1. Figure 2. 



6. Leaves opposite (fig. 3) Bidens, p. 140. 



6. Leaves alternate or irregularly placed 7. 



7. Leaflets usually 3, no more than 5 (fig. 4) Ranunculus, p. 118. 



7. Leaflets more than 5 8. 



