248 16. HYPERICACE.E. 



sepals than usually seen in H. perforatum, though less 

 broad and obtuse than those of dubium. Specimens col- 

 lected in Devon and Hampshire are undistinguishable by 

 any character of the calyx, from those collected in Arran. 

 The question of species seems to resolve itself into this: — 

 Is H. maculatum a distinct species in nature, or only a 

 book species, made up by combining those examples of 

 dubium and perforatum which approximate in the abnor- 

 mal character of their calyx ? And if H. maculatum be 

 thus only a book species, are those intermediate forms, so 

 named, sufficient evidence to prove H. dubium and H. 

 perforatum varieties of one varying species ? T am myself 

 inclined, though not confidently so, to answer the former 

 question in the affirmative, and the latter in the negative. 



219. Hypericum quadkangulum, Linn. 



Area 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17. 



South limit in Cornwall, Isle of Wight, Sussex. 



North limit in Ross-shire, Aberdeenshire, Argyleshire. 



Estimate of provinces 17. Estimate of counties 75. 



Latitude 50 — 58. British type of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 100 or 200 yards, in England. 



Range of mean annual temperature 52 — 46. 



Native. Inundatal. Like all the other species of its 

 genus, in Britain, this one decreases in fi-equency north- 

 wards ; but it is too generally diffused to allow of its geo- 

 graphic type being restricted to the English. Having 

 seen this species near Callander, close upon the Highland 

 borders, I carry down its range of temperature to 46. If 

 growing also inland within the county of Ross, this would 



