In each country these seven natural orders include nearly half the Dicotyledonous plants. But in the Canaries the Crassulaceæ with 31 species should replace the Cruciferæ, and the Umbelliferæ be excluded.

The natural orders which are indigenous to the three Archipelagos of the Canaries, Madeira, and the Azores, but which are absent in Marocco, and the reverse are:—

In the Archipelago, but not in Marocco.In Marocco, but not in the Archipelago.
Simarubeæ (Cneorum)Berberideæ
PittosporeæCapparideæ
TernstrœmiaceæPolygaleæ
IlicineæAmpelideæ
MyrsineæCoriarieæ
Phytolacceæ (Bosea)Saxifrageæ
MyriceæApocyneæ
Commelyneæ (introduced?)Lentibularieæ
Nyctagineæ
Ulmaceæ
Cupuliferæ
Ceratophylleæ
Alismaceæ
Juncagineæ
Melanthaceæ

In the above lists the Commelyneæ are most probably introduced by man into the Canaries, and the absence of Lentibularineæ, Ceratophylleæ, Alismaceæ, and Juncagineæ in the Archipelago may be due to the want of suitable localities. The total absence of Cupuliferæ in all the Macaronesian Archipelago is inexplicable; and of Quercus especially, a genus so prominently developed in number of species and individuals on both continents, and which further abounds in both the Pliocene and Miocene beds of Europe.

The apparently indigenous Macaronesian genera which are wanting in Marocco are the following. Those in capitals are confined to the Canaries, or to the Canaries and Madeira:—

Malvaceæ
Abutilon
Cruciferæ
Parolinia
Barbarea
Simarubeæ
Cneorum
Celastrineæ
Gymnosporia
Sapindaceæ
Melianthus?
Leguminosæ
Spartium
Ulex
Rosaceæ
Bencomia
Alchemilla
Fragaria
Aquifoliaceæ
Ilex
Pittosporeæ
Pittosporum
Ternstrœmiaceæ
Visnea
Umbelliferæ
Todaroa
Rubiaceæ
Phyllis
Plocama
Compositæ
Chrysocoma
Allagopappus
Vieræa
Doronicum
Serratula
Prenanthes
Campanulaceæ
Musschia
Canarina
Wahlenbergia
Ericeæ
Clethra
Asclepiadeæ
Ceropegia
Convolvulaceæ
Cressa
Boragineæ
Tournefortia
Labiatæ
Bystropogon
Cedronella
Verbenaceæ
Lippia
Solaneæ
Nicandra
Scrophularineæ
Campylanthus
Lyperia
Acanthaceæ
Justicia
Oleineæ
Notelæa
Myrsineæ
Myrsine
Sapotaceæ
Sideroxylon
Primulaceæ
Pelletiera
Chenopodieæ
Traganum
Laurineæ
Persea
Apollonias
Ocotea
Phytolacceæ
Bosea
Urticeæ
Gesnouinia
Myriceæ
Myrica
Aroideæ
Dracunculus
Liliaceæ
Dracæna
Cyperaceæ
Fimbristylis
Cladium
Gramineæ
Chloris
Tricholæna

There are in Marocco, out of a total of 517 genera, 202, included under 67 orders, that have no indigenous species in the Canaries or Madeira. Many of these, about a quarter, being North Maroccan, i.e. only found in parts of Marocco farthest from the Canaries, would not be expected to occur in those islands, were it not that the vegetation of islands near to large continents often most resembles that of a higher latitude on the continent than that in which the islands are situated.

The following is a list of the Maroccan genera which are absent in Macaronesia;—those confined to North Marocco marked *; those which have been found in Macaronesia, but certainly introduced, marked ‖; those in italics have been discovered since our return from Marocco.[13]

Clematis
Thalictrum
*Anemone
Aconitum
Berberis
Rœmeria
Corydalis
Cardamine
Morettia
Anastatica
Draba
*Erophila
Malcolmia
Diplotaxis
Moricandia
‖Lepidium
Thlaspi
Iberis
Hutchinsia
Isatis
Ceratocnemum
*Cakile
*Hemicrambe
Cleome
Capparis
Caylusea
Fumana
Polygala
Velezia
Dianthus
Holosteum
Buffonia
Lœfflingia
Montia
Althæa
Malope
*Radiola
Peganum
Celastrus
Zizyphus
Acer
*Coriaria
Lotononis
Crotalaria
Argyrolobium
*Calycotome
Anthyllis
*Securigera
Coronilla
Colutea
*Glycyrhiza
Hedysarum
Ornithopus
Ebenus
*Pisum
Ceratonia
‖Acacia
Saxifraga
Parnassia
Ribes
*Drosophyllum
*Peplis
*Ecbalium
*Hydrocotyle
Eryngium
Deverra
Hippomarathrum
Kundmannia
*Magydaris
Sclerosciadium
Meum
Heracleum
*Peucedanum
‖*Coriandrum?
Thapsia
Elæoselinum
Gaillonia
Putoria
Callipeltis
Asperula
Crucianella
*Valeriana
‖Centranthus
*Fedia
Nidorella
Nolletia
Micropus
Leysera
Grantia
Anvillea
*‖Xanthium
Achillea
Cladanthus
Echinops
Xeranthemum
Onopordon
Stæhelina
Crupina
*Leuzea
Carduncellus
Catananche
Hyoseris
Phœcasium
Hieracium
Scorzonera
Jasione
Trachelium
*Calluna
Armeria
Limoniastrum
Plumbago
Coris
Argania
Fraxinus
Phyllyrea
*Vinca
Nerium
Dæmia
Glossonema
Boucerosia
*Microcala
Cicendia
Trichodesma
Echinospermum
Rochelia
Nonnea
Cerinthe
Calystegia
*Mandragora
Anarrhinum
*Pinguicula
‖*Acanthus
Vitex
Lycopus
*Satureja
Hyssopus
Cleonia
Zizyphora
*Betonica
Ballota
Boerhavia
Corrigiola
Scleranthus
Sclerocephalus
Polycnemum
Telephium
*Obione
Salicornia
Caroxylon
Passerina
Osyris
Andrachne
*Ulmus?
Celtis
Quercus
Populus
Ceratophyllum
Callitris
Cedrus
Aceras
*Serapias
*Cephalanthera
*Crocus
Leucojum
*Lapiedra
*Tapeinanthus
*Corbularia
Narcissus
Aurelia
*Alisma
Damasonium
*Triglochin
Chamærops
Gagea
*Hyacinthus
Anthericum
*Simethis
*Aphyllanthes
Colchicum
Erythrostictus
*Convallaria
*Schœnus
*Leersia
Lygeum
*Crypsis
*Alopecurus
Macrochloa
*Sporobolus
Ammophila
‖Arundo
*Ampelodesmos
Phragmites
Pappophorum
Echinaria
*Spartina
*Airopsis
Gaudinia
Glyceria
Secale
Elymus
*Lepturus
Anthistiria

These 202 genera, which are absent in the Canaries, comprise upwards of 300 Maroccan species, including Eryngium, with eleven species, Coronilla with eight, Diplotaxis with seven, Narcissus, Anthyllis, Polygala, Passerina, and Quercus five each, besides twenty other genera with three or four each. Not a few of them contain very common and wide-spread species, as do all the above-named, as well as Clematis, Malcolmia, Cardamine, Dianthus, Hedysarum, Heracleum, Asperula, Achillea, Onopordon, Hyoseris, Scorzonera, Phyllyrea, Fraxinus, Calystegia, Anarrhinum, Ballota, Populus, Chamærops. That no species of these or of many of the other genera should exist in the Canaries is inexplicable, considering the position and extent of the Archipelago, and the means of migration which must exist between it and the mainland.