WATER FENNEL 69 



Water Fennel (Ranunculus trichophyllus, Chaix.) 



Seeds of Batrachian Ranunculi, which come under the old aggregate 

 Ranunculus aqiiatilis, have been found in some deposits, such as Pre- 

 glacial, Early Glacial, Interglacial, Late Glacial, and Neolithic beds. 

 To-day the distribution of this aggregate extends over Europe, West 

 Asia, the Himalayas, N. America, or the Warm Temperate Zone. 

 In occurrence it is absent from Cornwall in the Peninsula, South Hants 

 and E. Sussex in the Channel province, but occurs throughout the 

 Thames province; in Anglia it is absent from Northampton, but present 

 in the whole of the Severn province, and absent from Notts in the 

 Trent province, occurring in Carnarvon and Denbigh only in Wales, 

 in S.W. and N.E. Yorks, Tyne province, and in Scotland in Dum- 

 fries, Kirkcudbright, Hadclington, Edinburgh, Fife, Stirling, Perth, 

 Forfar, Clyde Islands, Sutherland, and the Hebrides. It is also found 

 in Ireland. 



In all the Water Buttercups the leaves are much divided. There 

 are two types. Those that float are rounded with 3-6 wedge-shaped 

 lobes, which are inversely egg-shapecl or rounded. The submerged 

 leaves, on the other hand, are linear, much divided, with numerous fine 

 segments. There are other modifications of this type, some, as R. 

 fluitans, having no floating leaves, but very long hair-like leaves (sub- 

 merged) only when growing in quickly-flowing water. At the other 

 extreme are plants, as R. kederaceiis, with few if any submerged or 

 thread-like leaves, and only the rounded floating types of leaf. The 

 types with two kinds of leaves may become stranded on land and then 

 adapt themselves to such conditions, though as a rule the submerged- 

 leaf type cannot succeed on land or the floating leaf under water. 



This species is an aquatic like other Batrachian Ranunculi, with 

 thread-like submerged leaves, hydrophilous, preferring the still water 

 of a pond or lake to that of running water, thus differing from Ranun- 

 culus penicillatus. It forms clusters and groups growing in the centre 

 of the poncl, and is associated with Water Cress, Water Persicaria, 

 Pondweeds, Duckweed, Water Plantain, and the semi -submerged 

 Celery-leaved Water Crowfoot. 



Water Fennel is adapted, like all aquatic plants, to growth in water, 

 with linear leaves and slender stems which float readily in the water. 



Water Fennel is distinguished from other Water Buttercups by its 

 small flowers, its rigid leaves which do not collapse when removed 

 from the water, and the short compact flower-stalk. 



