The Flora of the Canarian Archipelago, though consisting, like the Maroccan, for the most part of Mediterranean species, yet differs from that of Marocco, in containing many plants that may be classed under the following categories:—
I. It contains many non-Maroccan plants, obviously introduced by man, and not from Europe only, but from various parts of both the Old and New Worlds. This will not appear surprising when it is remembered that Teneriffe was for several centuries the Prime Meridian of Geographers and the resort of all the European ocean-navigators, who took their departure from it on their outward voyages, and made for it on their homeward ones. The Alternanthera achyrantha, a tropical American plant, was no doubt imported into the Canaries, and possibly from thence introduced into Spain (where it is now naturalised). Argemone mexicana is another, and there are still other as conspicuous examples of such foreign introductions. This maritime intercourse can, however, only partially account for the remarkable disproportion between the number of probably introduced plants in the Canaries and in Marocco; and we must take into account the isolation, barbarism, and exclusiveness of the latter country, and the absence of any commercial intercourse between it and the Canaries or the rest of the world.
In Webb and Berthelot’s ‘Phytographia Canariensis’ upwards of fifty plants are enumerated as to which we have little doubt that all have been introduced by man, and none of which have hitherto been found in Marocco. The list includes many weeds of the widest tropical and temperate distribution, as species of Sida, Waltheria, Siegesbeckia, Bidens, Lippia, Physalis, Nicandra, Euphorbia, Alternanthera, Commelyna, and various Cyperaceæ, and Grasses.
II. The Canaries contain many apparently indigenous plants, which, though not Maroccan, are widely distributed elsewhere; these form a large class, and the following are some of the most prominent of them:—
| Delphinium Staphysagria | Fragaria vesca |
| Hypecoum procumbens | Pyrus Aria |
| Biscutella auriculata | Prunus lusitanica |
| Viola canina | Epilobium palustre |
| Silene Behen | Anthemis fœtida |
| „ nutans | „ coronopifolia |
| Rhus Coriaria | Cynara horrida |
| Spartium junceum | Lactuca sylvestris |
| Ulex europæus | Cressa cretica |
| Medicago arborea | Calamintha Nepeta |
| Trigonella hamosa | Atriplex glauca |
| Trifolium striatum | Euphorbia serrata |
| „ squarrosum | „ obliquata |
| „ suffocatum | „ Lagascæ |
| „ filiforme | Orchis longibracteata |
| Lotus angustissimus | Ophrys tabanifera |
| Vicia hirsuta | Iris pallida |
| Lathyrus odoratus | Lilium candidum |
| Alchemilla arvensis |
together with various Cyperaceæ, Grasses and water-plants, some of which, and of the above, will no doubt hereafter be found in Marocco.
III. They contain some quite peculiar plants which are more closely allied to endemic species of Marocco than to those of any other country, and may have been derived from species that originally were transported from that country. These are but few, and are almost confined to species of the genus Monanthes, which is limited to these countries and the Cape de Verde Islands, of Cactoid Euphorbiæ, of succulent Sonchi, and of the Kleinia division of Senecio.
IV. They contain plants not found hitherto in Marocco, and which are more closely allied to Mediterranean species than to any others; and these form a very large class. The data for a complete list would require a very careful comparison of the Maroccan species with the species described in the ‘Phytographia’ and discovered since, many of which are unquestionably founded on too slight or too variable characters.[5]
It will be sufficient for present purposes to contrast the results obtained from a selection of genera[6] taken for comparison from Ball’s ‘Spicilegium’ with the same from Webb’s ‘Phytographia’:—
| Genera | Canary Islands | Marocco | ||
|---|---|---|---|---|
| Number of species in each | Species confined to Canaries | Number of species in each | Species confined to Marocco | |
| Hypericum | 8 | 7 | 7 | 0 |
| Matthiola | 4 | 3 | 3 | 0 |
| Cistus | 2 | 1 | 7 | 0 |
| Helianthemum | 6 | 3 | 14 | 0 |
| Polycarpia | 6 | 4 | 1 | 0 |
| Sempervivum | 23 | 23 | 1 | 1 |
| Cytisus | 11 | 9 | 11 | 4 |
| Lotus | 10 | 6 | 14 | 2 |
| Dorycnium | 3 | 3 | 1 | 0 |
| Rhamnus | 3 | 3 | 3 | 0 |
| Ilex | 2 | 2 | 0 | 0 |
| Chrysanthemum | 12 | 12 | 11 | 4 |
| Senecio | 9 | 5 | 11 | 1 |
| Doronicum | 5 | 5 | 0 | 0 |
| Tolpis | 5 | 4 | 2 | 0 |
| Sonchus | 17 | 12 | 6 | 0 |
| Convolvulus sect. Rhodorhiza | 5 | 5 | 0 | 0 |
| Echium | 12 | 10 | 9 | 1 |
| Micromeria[7] | 17 | 17 | 1 | 0 |
| Sideritis | 6 | 5 | 7 | 2 |
| Teucrium | 3 | 1 | 11 | 4 |
| Solanum | 6 | 2 | 2 | 0 |
| Scrophularia | 5 | 3 | 9 | 1 |
| Digitalis | 2 | 2 | 2 | 0 |
| Statice | 9 | 9 | 13 | 3 |
| Plantago | 10 | 3 | 11 | 1 |
| Beta | 3 | 2 | 1 | 0 |
| Euphorbia | 19 | 9 | 22 | 6 |
| Ephedra | 3 | 2 | 2 | 0 |
| Juniperus | 2 | 1 | 4 | 0 |
| Pinus | 1 | 1 | 1 | 0 |
| Ruscus | 2 | 2 | 1 | 0 |
| Asparagus | 5 | 4 | 6 | 1 |
| Scilla | 4 | 4 | 9 | 0 |
| Luzula | 3 | 3 | 1 | 0 |
| 243 | 187=¾ | 204 | 31=⅙ | |