284 



KNOWLEDGE. 



[December, 1901, 



giving a rugged stu-face and a bold and irregular coast- 

 line; tracts of limestone, generally of low elevation, 

 alternate with bolder masses of mctamoi-pliic and 

 igneous rocks; the exposure is great; the air moist 

 and warm on account of the adjoining ocean and the 



FiG.l. — Disti-ibutiouoflv'ortlierii Fig. 2. — Distribution of Pyre- 

 'lants (Watson's Scottisli and In- noan and Mfditen-anean Plants in 

 evraediate Tyjies) in Ireland. Ireland. 



prevalence of westerly winds; there is a high rainfall 

 and much cloud; glacial deposits are frequently absent. 

 The effect of these conditions is to reduce the amount 

 of cultivated land and of woods; to increase the area 

 of bog and moor; and as regards the character of the 

 flora, to decrease the number of plants that love a light 

 soil, a di-y climate, or abundance of sunlight; and to 

 increase the number of mountain plants, and of species 

 averse to the rigour of hard winters. Here the artificial 

 element of the florarweeds of cultivation, and introduced 

 plants of all kinds — is at its minimum ; in marked con- 

 trast to the east coast, the flora of large ai-eas is strictly 

 natural, uninfluenced by the works of man. Among 

 this virgin vegetation we find a group of plants— indeed, 

 several groups of plants — which at once arrest attention 

 by their unfamiliai-ity. Some of these are widely spread 

 along the western sea-board ; others discontinuously dis- 

 tributed ; while a few have a limited local range. Most 

 of these plants are unknown, not only in the rest of 

 Ireland, but throughout Great Britain as well. Investi- 

 gation shows that they can be divided into three gi-oups 

 of widely different origin:— (1) Plants whose head- 

 quarters IS m the Pyrenees or along t-he Mediterranean ; 

 (2) plants characteristic of the northern part of Noith 

 America; (3) plants usually occurring in alpine situa- 

 tions, but -here growing right down to sea-level 

 Particulars regarding the distribution of some 

 characteristic members of each of these groups will 

 emphasize the remarkable character of these elements 

 of the flora: — ■ 



SouTHEEN Plants.— 6W//A,,y,, >uubro,a.— In Ireland 

 widely spread along south and west coasts from AVater- 

 tc)rd to Donegal, avoiding the limestone. Unknown in 

 Britain. El.sewhere confined to the Spanish Peninsula. 



Saxifraya Oexm.—Vreqm'nt in extreme south-west. 

 Unknown in Eiitain. Elsewhere restricted to the 

 Pyrenean region. 



Arbutus FwefZo.— Extreme south-west. Unknown in 

 Britain. Widespread in the Mediterranean region 



Prmimc„laj,ra,uliflom. -Common in the south-west. 

 Unknown m Britain. Elsewhere confined to the Spanish 

 Peninsula and the Alps. 



Erica mediierranea, E. Mackaii, Dabeocia polifolia. — 

 Three Iieaths confined to West Galway and Mayo. Un- 

 known in Britain. Elsewhere found only in South-west 

 France and Spain ; the last-named extending to the 

 Azores. Note that two other heaths. E. cilia r is and 

 E, vmjans, in the British Isles found only in the south- 

 west of England, have the same distribution on the 

 C(nitineiit. 



Eupltiirbid hihtnia. — Common in the south-west and 

 extending thence discontinuously to Donegal. Devon only 

 in Britain. Elsewhere confined to Pyrenean region. 



Hahenaria intacta. — Widespread on the western edge of 

 the limestone from Clare to Mayo. Not in Britain. Else- 

 where in Mediterranean region and Asia Minor. 



North American Plants. — Spiranthes Boinauzoffiana. 

 — Found in Cork, also in the north-east. Unknown else- 

 where in Europe. Of frequent occurrence in Canada and 

 the northern United States, and in Kamtschatka. 



Eriocanloti septangulare. — Spread aloiiLj the west coast 

 from Cork to Donegal. On one island in Scotland (Skye). 

 Unknown on the European continent. Widespread in 

 northern North AiiK.'vica. 



Low-LEvEL Alpines and Northern Plants. — The 

 most remarkaljle disj.lay of these is on the bare limestone 

 hills of North Clare, and the low limestone pavements 

 adjoining, where Bryas ocfopetala, Gentiana vcriia. 

 Arctodaphylos Uva-ursi, Sesleria aerulea, and similar 

 plants grow, often in marvellous profusion, right down 

 to sea-level. 



As regai-ds this third group, the peculiar climatic 

 conditions must be held accountable for their abundance 



FiO. 3.— AVild .Arbutu.s at the Upper Lake, Killarney. 

 Macgillicuddy's Recks (3414 feet) in the distance. 



[K. Welch, Photo. 



here — the exposure and dampness which characterize 

 the western coast apparently mimicking the conditions 

 which prevail in their accustomed highland haunts. But 

 considerations of a meteorological kind, though they 

 may help to account for the extraordinaiy niixiii'f 



