Clare Island Survey — Phanerogamia. 10 31 



Carex Oederi, Eetz. — Seems characteristic of the Plantago sward. The var. 

 oedocarpa, And., also occurred. 



Hymenophyllum unilaterale, Bory. — Very abundant on Croaghmore up to the 

 summit. On the scarp it forms bosses along with Mnium hornum, 

 resembling those of Silene acaulis. It descends to about 500 feet on the 

 north-east flanks of Knoeknaveen, 200 feet at Craigmore, and at Portlea 

 occurs at storm-level on the edge of the boulder beach. 



Cystopteris fragilis, Bernh. — Several small colonies on the Croaghmore scarp 

 at 1,200-1,400 feet. 



Aspidium Lonchitis, Swartz. — Three colonies, each of about a dozen plants, 

 on the 1,200-foot path on Croaghmore. 



Osmunda regalis, L. — Common. Great tussocks growing in pasture-land are 

 left, as large boulders might be, on account of the labour required to 

 remove their dense matted roots. On wet clay in shady positions 

 seedings in all stages are often very abundant. A fine cristate form 

 found near Ballytoohy is figured in " Irish Naturalist," xii, 291. 



5. THE INFLUENCE OF MAN UPON THE FLOKA. 



As regards the general history of the effect of human activity on the flora 

 of Ireland we have not much to go upon. We begin with an aboriginal 

 vegetation, its characters being the result of past geological changes, of local 

 climate and soil, plus the overmastering influence of the native fauna, from 

 grazing quadrupeds down to the lowest forms of animal life. The advent of 

 the human race at first can have made no appreciable difference. So long as 

 man merely hunted, his influence on the vegetation was very small. When 

 he became a keeper of flocks, he must have influenced the flora locally, chiefly 

 by reduction, owing to plants being prevented by grazing from increasing, 

 or from maturing seed. But when he began to use fire for clearing the wood- 

 land, and to till the ground, not only did his operations destroy the local 

 plant-formations, but the carrying and bartering of grain, for sowing or for 

 food, must have tended to spread the seeds of many plants. 1 



All through the Middle Ages, and on through modern times, as trade and 

 commerce increased, as towns grew, as lines of transportation spread across 

 the world, and railways and steamboats linked cities and countries together, 

 the scattering of alien seeds has ever gone on more and more, till nowadays 

 a dozen American or Kussian plants may often be found growing together in 

 our own islands near centres of industry or of traffic. Becent studies by 



1 See A. ue Candolle: Origin of Cultivated Plants (English edition), chap. i. 1884. 



