378 PLANTS, SEEDS, AND CURRENTS 



and he considers that the acids secreted by the Peat-mosses would 

 be neutralised by the alkaline ground- waters. In the coastal swamps 

 of the Carolina region a large fern, Woodwardia virginica, grows out 

 of low Sphagnum tussocks which are surrounded by standing water 

 (Harshberger's Phyt. Surv. N. Amer., p. 441). The Pico locality, 

 it should be noted, lies in the midst of a district of basic lavas, rather 

 over 2000 feet 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, Car ex stellulata, and Scirpus multicaulis, 

 the last in proliferous condition. In the water thrive Callitriche 

 aquatica, Potamogeton polygonifolius, and Scirpus f.uitans. Watson, 

 in his paper in the London Journal of Botany for 1843, gives a list 

 of the plants growing in and around some of these pools on the upland 

 moors which he passed on his way to the summit. They include 

 Callitriche verna, Carex stellulata, Peplis portula, Potamogeton natans 

 (subsequently referred to P. polygonifolius), Scirpus fluitans, and 

 Sc. savii. Further remarks on the aquatic and sub-aquatic plants 

 of the island of Pico will be found in the following chapter. 



The Secondary Cones on the Slopes of the great Mountain 

 of Pico. — Reference has more than once been made to the craters 

 of these numerous small cones as sanctuaries for plant life. They 

 vary usually from 50 to 250 feet in height, and as far as could be 

 gathered show no signs of volcanic heat, their interior as well as 

 their exterior slopes being either grassy or w T ooded. Many of them 

 are situated in the upland moors or in the zone of the upper woods, 

 that is to say, at elevations of from 2000 to 5000 feet above the sea. 

 In some instances the craters are inaccessible, and in one case, where 

 a narrow gap led into the crater, the interior was once used as a 

 corral for cattle. I ascended many of them, and the vegetation of 

 their outer slopes depends on whether they rise up in the moors 

 or in the woods. Their craters are usually dry, and only in the case 

 of the smallest cones do they hold shallow ponds, the abode of aquatic 

 plants. In one such crater pool Potamogeton polygonifolius grew 

 in the water and Scirpus multicaulis at its sides, there being a growth 

 of Sphagnum at its border. (In the case of the numerous crater 

 lakelets, that occur off the great mountain in the eastern part of 

 the island, a few remarks will be made later on in this chapter.) 

 Some of the cones are very regular in form, and one may mention 

 in this connection the Cabeza Norte, which lies at the foot of the 

 cone proper on its W.N.W. side about 4000 feet above the sea. 

 It has a height of 200 feet, and its crater, which is remarkably 

 symmetrical in shape, is 500 feet across and is as deep as the hill is 

 high. Its interior is partly clothed with shrubs, mostly Erica 

 azorica, with a little Ilex per ado. 



The Lake District of the Island of Pico. — This region is 

 separated from the eastern slopes of the great mountain by a broad 

 saddle, or elevated plain, which is raised not less than 2000 feet 

 above the sea. The plain is dotted with small volcanic cones, and 



