474 79. HYDROCHARIDACEiE. 



number of provinces mentioned in the estimate, it is sup- 

 posed to have been introduced to four of them, and cer- 

 tainly known to have been originally planted by botanists 

 in some of the localities, as in Surrey and Forfar. All the 

 counties in which it is recorded to occur, and believed to 

 be indigenous, are eastern, with the exceptions of Lancas- 

 ter and Chester. 



1108* Anacharis Alsinastrum, Bab. "^ ^'^^^ J-Syf^ 



Area ^^2*45*^8***** 14. 



South limit in Hants, Northampton, Stafford. 



North limit in Edinburgh, Berwick. 



Estimate of provinces — ? Estimate of counties — ? 



Latitude 52 (50) — 56. Uncertain type of distribution. 



Agrarian region. Inferagrarian — Midagrarian zones. 



Descends to the coast level, or nearly so. 



Ascends to 100 yards, less or more, in East Lowlands. 



Range of mean annual temperature 49 — 47. 



Denizen. Lacustral. First announced as a British 

 plant about the close of 1847, under name of Udora verti- 

 cillata. Doubts were soon suggested respecting its nativity 

 in Britain, from the circumstance of its being shortly after- 

 wards observed in ponds, to which it might possibly, and 

 even not improbably, have been introduced from America. 

 Mr. Borrer found it in a pond in Leigh Park, near Havant, 

 in the south-east of Hants, which is the most distrusted 

 locality for it in England. Mr. Kirk (Phytol. iii. 389) ob- 

 served it abundantly in the reservoirs at Watford Locks, 

 " on the same line of canal as Foxton Locks," in Leices- 

 tershire. The reservoirs at Foxton Locks, near Market 

 Harborough, were the original habitat, in which it was 

 discovered^ by Miss Kirby, and subsequently gathered 



