Mr. J. Ball on some British species of the genus (Enanthe. 7 



suspects between the fresh and salt water forms*. The following 

 is the description : — 



(Enanthe Lachenalii. — Radix. . . Caulis erectus, striatus, fistulosus seu 

 subfarctus, alterne ramosus, 1 — 3-pedalis. Folia radicalia pinnata, 

 pinnis pinnatifidis trifidisve insequalibus, segmentis obverse lanceo- 

 latis obtusis venosis, petioli mediocris longitudinis basi vaginante ; 

 caulina pinnata longe petiolata pinnis trifidis segmentis linearibus 

 acutis valde elongatis ; successiva minora, demum simplicia, seg- 

 mentis semper insequalia. Umbellse solitarise, terminales, 5 — 15- 

 radiatse, longe pedunculatse. Involucrum universale 0, seu 1 — 6- 

 phyllum, foliolis linearibus acutis, umbella multo brevioribus. 

 Umbellulse multiflorse, floribus externis sterilibus longius pedicel- 

 latis, internis subsessilibus in fructu fastigiatae. Involucella um- 

 bellula brevior e foliolis lanceolatis margine pallentibus nonnullis 

 basi connatis. Petala radiantia quam in (E. silaifolia paululum 

 majora profundius obcordata. Styli diachenio breviores, parum 

 divergentes. Stylopodium majusculum, conicum. Diachenium 

 basi non calloso semper angustatum, variat tamen magnitudine 

 et forma; interdum majus usque ad summum dilatatum quasi 

 obconicum, interdum (prse siccitate ut videtur) minus, sub calyce 

 (diviso in segmenta erecta insequalia) constrictum. 



In foreign specimens from the Bolognese Apennines, the fruit is 

 more exactly as described by Koch. The form of the lower leaves 

 is very constant in all the forms of this otherwise variable species. 

 The variation in the form of the fruit is very singular, but with 

 the specimens before me I cannot refuse to believe it. 



A word as to the value of the characters of these species. The 

 position and size of the tubers of the root are, I suspect, of doubt- 

 ful constancy ; observation must determine their importance. The 

 general disposition and proportions of the leaves are probably 

 much to be depended upon here and throughout the whole order. 

 The hollowness or solidity of the stem depends, I believe, almost 

 wholly on the place of growth, and is of no moment. The invo- 

 lucre is most variable. The petals vary somewhat in size but 

 scarcely in form, those of the outer sterile floret being always 

 compared with each other. The form of the fruit seems not so 

 constant as might be expected. The presence or absence of the 

 incrassated summit of the pedicel I have never seen to vary. 



I need scarcely add, that the above descriptions are taken ex- 

 clusively from the British specimens referred to. 



Dublin, March 10, 1844. 



* No difference exists between them. — C. C. Babington. 



