The disproportion between the two Floras in the case of these selected genera is thus well shown. It is most remarkable; the number of endemic species being in the Canaries three-fourths of the whole and in Marocco only one-sixth; and were the peculiar genera of the Canaries added, the disproportion would of course be increased.
The total number of Canarian species enumerated by Webb and Berthelot is about 1,000, of which 367,[8] or more than one-third, are regarded as peculiar to the Archipelago (a very few only of these being also Madeiran); whereas out of 1,627 Maroccan species only 165, or a little over one-tenth, are peculiar. Future discoveries will probably not materially increase the Maroccan proportion of peculiar species; whereas since the publication of Webb’s ‘Phytographia’ many peculiar species (especially of Statice and Crassulaceæ) have been discovered in the Canaries, and but few species common to other countries; and these additions will go far to neutralise any error introduced into the estimate, due to the great number of new species founded on insufficient data which the ‘Phytographia’ includes.
Under this head also should be included the peculiar Canarian genera that appear to be modifications of continental ones. They are Bencomia, closely allied to Poterium, of which there are two species, both confined to one Island (Teneriffe); one of these is also a native of Madeira, where only two individual trees, a male and a female, have ever been seen! Gesnouinia, allied to Parietaria; and Canarina, a monotypic genus allied to Campanula, but having a baccate fruit. Bosea, also a monotypic plant, is wholly unlike any known genus, and is, in some respects, intermediate between the two very distinct natural families—Chenopodiaceæ and Phytolacceæ.
V. Many Canarian plants are representatives of Floras more distant than those of Marocco or Western Europe, and are not found in those countries. These form an exceedingly interesting group, and may be classed according to countries thus:—
a. Oriental.—These are chiefly Arabo-Egyptian, but some of them extend even into Western India, and a few are representatives of tropical India. Some will no doubt yet be discovered in Marocco, especially south of the Atlas; and it is not unreasonable to suppose that such have crossed Africa in a subtropical latitude, and thus reached the Canaries under conditions now operating.
The most remarkable are the following. The genera in capitals have not hitherto been found in Marocco:—
| Polycarpon succulentum | Campylanthus salsoloides |
| Visnea Moccanera | Traganum nudatum |
| Gymnosporia cassinoides | Apollonias barbusana |
| Trigonella hamosa | Euphorbia Forskählii |
| Senecio flavus | Dracæna Draco |
| Ceropegia dichotoma |
Of the above hardly any have been found west of the Levant, or anywhere between Egypt and the Canaries, except, possibly, in Southern Algeria. Traganum must be reckoned as an African and Oriental desert type, and will probably be found in South Marocco; but Ceropegia is mainly Indian, as is Gymnosporia (Catha cassinoides, Webb). Campylanthus consists of the Canarian species, of a variety or closely allied one in the Cape de Verde Islands, and of a third which extends from Southern Arabia to Scinde. The nearest ally of the Apollonias (Phœbe barbusana, Webb) is a Ceylon tree; and Visnea is nearly allied to the Malayan genus Anneslea. Dracæna Draco is the most interesting of all in the list; for, though the genus abounds in tropical Africa, the Canarian form, which is also a native of the mountains of the Cape de Verde Islands, has only one near ally, the D. Ombet, which is confined to Abyssinia, Southern Arabia, and the intervening Island of Socotra.
b. The peculiar species representing American types inhabiting the Canaries or Madeira, but not found in Marocco, are in some respects even more remarkable than the Oriental.
They belong to the following genera:—