CHAP. Lxvii SUBGLACIAL FELL-FIELD FORI^IATIONS 259 



to Venezuela ; these support the typical, open vegetation, the individuals 

 of which are scattered in small tufts, and display growth-forms exactly 

 orresponding to those in northern fell-fields ; cushion-like growth is 

 perhaps more common. But other species and genera impart to the 

 vegetation a distinctive appearance ; in addition to Viola, Anemone, 

 Alchemilla, Draba, Senecio, Gentiana, Poa, Hordeum, and many other 

 European genera, there are found Nassauvia, Chuquiraga, species of 

 Baccharis of wondrous shapes, and other Compositae, Tropaeolum, 

 Loasa, Blumenbachia, Verbenaceae, Cactaceae, Calceolaria, Mimulus, 

 Melastomaceae, Krameria, Lupinus, Calyceraceae, and others. The 

 umbelliferous genus Azorella deserves special mention.^ The rhododen- 

 drons of Switzerland are replaced here by species of Escallonia and 

 Bejaria. 



Here, too, one finds the composite genera, Espeletia and Culcitium 

 (termed ' frailejon '), of which Espeletia grandiflora is a remarkable plant 

 attaining a height of 2 metres, and remaining unbranched. The stem is 

 clothed with numerous dead remnants of leaves, that form an investment 

 as thick as a man's body ; while higher up it bears a number of leaves 

 enveloped in very thick coatings of wool, and inflorescences. In the 

 highest regions these genera, together with short alpine herbs, grasses, 

 and ferns, form the sole vegetation.'^ 



Despite great humidity, frequent rain and mist, which the sun may 

 suddenly dissipate, the vegetation is xerophytic, as Gobel's descriptions 

 demonstrate : many plants occur with pinoid, cupressoid, juncoid, or 

 woolly-haired leaves. On the Chihan piinas, according to Meigen,^ 

 mosses and lichens are greatly curtailed, lichens occur only at isolated 

 spots in any abundance ; while mosses never form a carpet or an extensive 

 cushion. Extreme dryness is the cause of this. 



Africa. The vegetation on high African mountains is of similar 

 character. Viewed from a distance it seems to be a continuous grassy 

 sward, but closer inspection shows that the tufts of grass are isolated. 

 Grasses and sedges give rise to cushions, whose size varies from that of 

 the human fist to that of a dinner-plate ; and their haulms, about 70 centi- 

 metres in height, rise up from the axils of leaves which are erect or have 

 fallen backwards on to the ground. In the dry season the soil is bare 

 or is clothed with a mat of mosses and lichens. Shortly after the rains 

 set in there shoot forth many herbs ; the first to appear are monocotylous 

 bulbous and tuberous forms, such as Hypoxis angustifoUa, Hesperantha 

 Volkensii, and others, which are succeeded by dicotylous herbs and 

 undershrubs, such as Wahlenbergia Oliveri, Tolpis abyssinica, and Hcli- 

 chrysum Meyeri-Johannis, and many others. Moreover, there are some 

 little trees which attain heights of from 5 to 8 metres and are bent away 

 from the wind to the south-west. Of these there are only a few species, 

 mcluding Agauria salicifolia. Erica arborea, and Ericinella Mannii. 

 Their boughs are hung with lichens. Higher up the tufts of grass become 

 scantier, while puny shrubs, especially Ericinella Mannii and Senecio 

 1 Johnstonii prevail. The last-named represents here the same growth- 

 form as Espeletia in South America. In Abyssinia it is replaced by the 

 lobeliaceous Rhynchopetalum montanum.'' 



' See next page. ' Gobel, 1891. * Mcigen, 1893- * Volkens, 1897. 



S 2 



