282 DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 



to the Alps and Pyrenees, Carpathians, Balkan, and Tauria (inclusive) in Europe, and to the Caucasus, 

 Altai and Soongaria (inclusive) in Asia. 1. Europe to the Alps. Here A. implies that the plant in- 

 habits the Alps, or Pyrenees, or Caucasus ; and N. that it is a more northern plant, not advancing south 

 of Germany or Central Russia, in many cases not south of Scandinavia. 2. Asia to the Altai, Soonyaria 

 and Dahuria; the eastern limit of this zone is supposed to be the Jablonoi range, and the western, 

 the Obi River. 3. Eastern Asia, from Behring's Straits to the south of Japan, including Mantchuria, 

 Kamtschatka, the peninsula of Ochotsk, North China, and the neighbouring islands of Japan. This 

 district presents a transition zone between the Asiatic and American floras, and were it better explored 

 might possibly be incorporated with the latter, in the higher latitudes at any rate. 



III. American Distribution. — 1. North-west America includes the band of country from the 

 Rocky Mountains to the Pacific. This is for the most part a very mountainous area, presenting two floras, 

 — -the Columbian, which extends south to the Oregon ; and the Californian, which extends north to that 

 river, and inland to a considerably higher but still unknown latitude. Being unable to define the limits 

 of these two floras, I have not indicated to which the arctic plants belong, but here, as in the following 

 column, an R. indicates that the species inhabits the Rocky Mountains. 2. North-east America. This 

 includes all temperate North America, from the Rocky Mountains to the Atlantic. In this column the 

 letter C. indicates that the species is Canadian, but does not enter the United States; L. that it is con- 

 fined to Labrador, R. to the Rocky Mountains, and W. that in the United States it h'as been only found 

 on the White Mountains of New Hampshire, or on other high mountains of the Eastern States. 3. Tro- 

 2)ical America. With fev/ exceptions the arctic plants found in this province are confined to the temperate 

 and alpine regions of the Cordillera from Mexico to Peru inclusive. M. signifies that it has been found 

 in, but not south of, Mexico. 4. Includes Extra-tropical South America and its islands. 



IV. South Europe and Africa. — 1. Europe south of the Alps, Asia Minor, the Ccmanj Islands, and 

 Africa north of the tropic. In this column are included the plants of the Spanish and Italian penmsulas, 

 Dalmatia, &c., Greece, and both Turkeys. Of these countries, Asiatic Turkey, or Asia Minor, should 

 perhaps have been ranked in the Asiatic column with Persia, &c. ; but it contains so very many European 

 plants that are not found further east, that I have included it here. The letter A. in this column indi- 

 cates that the plant actually crosses the Mediterranean to North Africa, and is found in Algeria, Egypt, 

 the Canary Islands, or the mountains of Abyssinia*. 2. South Africa, from the Cape of Good Hope to 

 the tropic. 



V. Central and South Asiatic Distribution. — 1. Persia, Tibet, and tlie Himalaya Mountains. 

 In tliis column the letter H. indicates that the species inhabits the Himalaya or Tibet. 2. Tropical Asia. 

 This includes all India south of the Himalaya, and especially the Khasia mountains of Eastern Bengal, 

 the mountains of both peninsulas of India, of Ceylon, and of Java. 3. The last column is confined to 

 Australia, New Zealand, and the antarctic islands to their south. 



The map that accompanies this paper is reduced from the latest Admiralty chart of the north polar 

 regions (that of 1860), by permission of Captain Washington, R.N., Hydrographer of the Admiralty. 

 The isothermal lines are taken from Professor Dove's Vv'ork ' On the Temperature of the Globe,' translated 

 by Major-General Sabine, and printed by the British Association for the Advancement of Science in 

 1853. I have selected what appeared to me the seven most instructive isotherms; namely, the annuals of 

 0° 5' Fahr., 5° and 32°; the two June isotherms of 32° and 41°, and the two September isotherms of 32° 

 and 4 1° ; these two months answering respectively to the flowering and fruiting seasons within the arctic 

 circle. 



* So fevv Arctic European plants have been found in Tropical Africa, that I have not devoted a column to it. 

 About twenty, however, have been identified either by Achille Richard, by the namers of the Schimper's and Kotsehy's 

 plants, or by myself in the Hookerian Herbarium. Even on Clarence Peak, a mountain on the isolated island of Fer- 

 nando Po, 10,600 feet high, arctic plants have been found by Mann, the collector for Kew, Beschampsia ceespitosu, 

 Luzula campestris, Galium aparine, and Limosella aqiiatica, together with two other boreal species, Sanicula Evropcea 

 and Brachypodium sylvaticum. 



