315 



ratlier over 2000 ft. above the sea. In midsummer its surface- 

 is but slightly moist and large masses of dead peat-mosses are- 

 seen. In winter the ground would doubtless be very wet. 



Here and there water collects in depressions of the boggy ground: 

 on these upland moors. Around the edges of the pools grow 

 Littorella lacustris^ Peplis portula, Carex stellulata, Scirpus 

 cernmis and Scirpus multicaulis in proliferous condition. In the 

 water thrive CallitricJie aquatica^ Potamogeton polygonifolius, and 

 Scirpus fiuitans. Around the large lakes lying to the east of the 

 peak in the mountainous region behind Caes-o-Pico, Praynha do 

 IS'orte, and Santo Amaro^ and elevated between 2500 and 3000 ft. 

 above the sea, one can sometimes recognise a succession of forma- 

 tions. Whilst the Potamogeton above named occupies the 

 shallows, Scirpus fluitans monopolises the soppy ground at the 

 lake's border, and outside this is a broad belt of Sphagnum where 

 Scirpus multicaulis, Carex jtava^ Anagallis tenella, and Hydro- 

 cotyle vulgaris thrive. Sometimes a tall form^ of Scirpus palustris, 

 two feet high, grows in the shallows. 



Littorella lacustris and Isoetes lacustris (var. azorica) are 

 common around some of these large mountain-lakes. Both display 

 two forms, a dwarfed form on the exposed mud-flats and a large 

 form with long cylindrical leaves, the latter growing either in 

 the deeper water (Isoetes) or where the water just cavers the ooze 

 at the lake's margin (Littorella), Whilst the dwarfed plants of 

 Littorella lacustris w^ere well in flower in the end of July, the 

 large plants were showing the flower buds; the latter possess 

 leaves, six to nine inches long, which lie prostrate in the water 



and not erect as is sometimes described. It was evident that the 

 floating growths of Potamogeton polygonifolius are inimical to 

 the growth of the large forms of Littorella lacustris and Isoetes 

 lacustris. They are rapidly extending in the ponds and lakes of 

 this island, and not improbably will ultimately exterminate the 

 last-named species. Almost all of the above-named aquatic and 

 subaquatic plants flourish in one or other of the numerous small 

 crater-lakes in the island, which, it may be added, have often 



Sphagnum borders. 



All the plants dealt with in the foregoing pages would be 

 regarded as indigenous. The native flora of the Azores was 

 probably extremely limited. The group has been colonized for 



more 



species have been introduced, either by accident or by intention. 

 Trelease considers that most of the existing plants have been 

 introduced largely through human agency since the discovery of 

 the islands (p. 87) ; and one cannot be many weeks in the groui> 

 without recognising the correctness of this opinion. Watson's 

 list of 439 flowering plants was increased by Trelease to about 560; 

 but I should imagine that the original flora did not comprise 200 

 species and that the plants that gave their impress to the vegeta- 

 tion did not amount to a hundred. The matter cannot be treated 

 here ; but by restricting the field of discussion to the native plants 

 it is evident that we assume a very great reduction in the size of 

 the flora that has often been described as indigenous to the Azores, 

 Watson, thoug-h he did not elaborate the point iust touched 



