82 82. TYPHACE,^. 



Estimate of provinces 18. Estimate of counties 70. 



Latitude 50 — CO. British type of distribution. 



Agi-arian region. Inferagrarian — Superagi-arian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 350 yards, in E. Highlands (Syme). 



Eange of mean annual temjDerature 51 — 43. 



Native. Paludal, Lacustral. These two plants, the 

 larger and smaller forms, hitherto included under one 

 name by British botanists, are separated in the tliii'd edi- 

 tion of the Manual of British Botany, following Fries. 

 The larger form approximates to S. simj^lex in size, and 

 in having the lower heads of flowers stalked ; and possi- 

 bly it may have been sometimes passed by for the S. 

 simplex. Although I am much inclined to believe in two 

 distinct species here, I am not able to separate their re- 

 corded localities, hitherto published imder the one name 

 of S. natans. Specimens of true S. natans (the larger 

 form) are in my herbarium from Northumberland (Mr. 

 Store}'), Surrey and Ai-gyle (H. C. Watson), Aberdeen 

 (Professor Dickie; Mr. J. T. Syme), Orkney (Dr. GilHes). 

 All my other specimens belong to the dwarf foi-m, or S. 

 minimum, which sometimes is seen left out of water, 

 and show an area for it extending from Suffolk to Suther- 

 land. Glen Clunie, in which Mr. Syme finds Sp. natans, 

 is the highest locality yet known to me. Adding together 

 the preceding localities, those in Babington's Manual, 

 and those mentioned by Mr. J. T. Syme in Bot. Gaz. iii. 

 158, we have provinces — 3, 7, 11, 13, 15, 16, 18 — for S. 

 natans apaii from S. minimum. 



