Botanists have divided the surface of Etna into seven regions. The first extends from the level of the sea to 100 feet above it, and in it flourishes the palm, banana, Indian fig or prickly pear, sugar-cane, mimosa, and acacia. It must be remembered, however, that it is only on the east side of the mountain that the level within the base sinks to 100 feet above the sea; and, moreover, that the palm, banana, and sugar-cane, are comparative rarities in this part of Sicily. Prickly pears and vines are the most abundant products of the lower slopes of the eastern side of Etna. The second, or hilly region, reaches from 100 to 2000 feet above the sea, and therefore constitutes, with the preceding, the _Regione Coltivata_ of our former division. In it are found cotton, maize, orange, lemon, shaddock, and the ordinary Sicilian produce. The culture of the vine ceases near its upward limit. The third, or woody region, reaches from 2000 to 4000 feet, and the principal trees within it are the cork, oak, maple, and chestnut. The fourth region extends from 4000 to 6000 feet, and contains the beech, Scotch fir, birch, dock, plaintain, and sandworth. The fifth, or sub-Alpine region, extending from 6000 to 7000 feet, contains the barberry, soapwort, toad-flax, and juniper. In the sixth region, 7,500 to 9000 feet, are found soapwort, sorrel, and groundsel; while the last narrow zone, 9000 to 9,200 feet, contains a few lichens, the commonest of which is the _Stereocaulon Paschale_. The flora of Etna comprises 477 species, only 40 of which are found between 7000 feet and the summit, while in the last 2000 feet only five phanerogamous species are found, viz., Anthemis Etnensis, Senecio Etnensis, Robertsia taraxacoides, (which are peculiar to Etna), Tanacetum vulgare, and Astragulus Siculus. Common ferns, such as the _pteris aquilina_, are found in abundance beneath the trees in the Regione Selvosa. This division has been advocated by Presl in his _Flora Sicula_.[16] He names the different regions beginning from below: _Regio Subtropica_, _Regio Collina_, _Regio Sylvatica inferior_, _Regio fagi Sylvestris_. These four are common to all Sicily. The three remaining regions, _Regio Subalpina_, _Regio Alpina_, and _Regio Lichenum_, together extending from 6000 to 9,200 feet, belong to Etna alone. [16] "Flora sicula: exhibens Plantas vasculosas in Sicilia aut sponte crescentes aut frequentissime cultas, secundum systema naturale digestas." Auctore G. B. Presl. Pragæ, 1824. At the conclusion of the first volume of Recupero's _Storia Naturale et Generale dell' Etna_ we find a somewhat different botanical division proposed by Signor Rafinesque-Schmaltz.[17] He makes his divisions in the following manner:-- 1. Florula Piedemontana. 2. Florula Nemorosa. 3. Florula excelsa o della Regione Discoperta. 4. Florula Arenosa o della Regione delle Scorie.