336 VIEWS, &C. PHYSIOGNOMY OF PLANTS. 



large quantities of the siliceous Tabaschir (Sanscrit tvakkschira, 

 cow-milk). We saw the Guadua advance in the pass of 

 Quindiu, in the chain of the Andes, to a height of 5755 feet 

 above the level of the sea, as determined by barometric mea- 

 surements. Nastus borbonicus has been called a true Alpine 

 plant by Bory de St. Vincent, and according to him it does 

 not descend lower than 3840 feet on the declivity of the volcano 

 in the island of Bourbon. This appearance or the repetition 

 at great elevations of certain forms belonging to torrid plains 

 calls to mind the group of Alpine palms (Kunthia montana, 

 Ceroxylon andicola, and Oreodoxa frigida) of which I have 

 already spoken, and a grove of Musaceae (Heliconia, perhaps 

 Maranta), 16 feet high, which I found growing isolated on 

 the Silla de Caracas, at a height of more than 7000 feet above 

 the level of the sea.* While the form of gramineae, with the 

 exception of some few herbaceous dicotyledons, constitutes 

 the highest phanerogamic zone on the snow-crowned summits 

 of mountains, so the grasses mark the boundary of phane- 

 rogamic vegetation in a horizontal direction, towards the 

 northern and southern polar regions. 



Many admirable general results, no less than a great mass 

 of important materials, have been yielded to the geography 

 of plants by my young friend, Joseph Hooker, who, after 

 having but recently returned with Sir James Ross from the 

 frozen antarctic regions, is now engaged in exploring the 

 Thibetian Himalaya. He draws attention to the fact that 

 phanerogamic flowering plants (grasses) advance 17^° nearer 

 to the north than to the south pole. In the Falkland 

 Islands, near the thick knots of Tussac grass, Dactylis 

 ca?spitosa, Forster, (a Festuca, according to Kunth), and in 

 Tierra del Fuego, under the shade of the birch-leaved Fagus 

 antarctica, there grows the same Trisetum subspicatum, 

 which spreads over the whole range of the Peruvian Andes, 

 and across the Rocky Mountains, to Melville Island, Green- 

 land, and Iceland, and is also found in the Swiss and Tyrolese 

 Alps as well as in the Altai, in Kamtschatka, and in Camp- 

 bell's Island, south of New Zealand, extending therefore 

 over 127 degrees of latitude, or from 54° south to 72° 50' 

 north lat. " Few grasses," says Joseph Hooker,f " have so 

 wide a range as Trisetum subspicatum (Beauv.), nor am I 



* Rclat. hist. t. i. pp. 605—606. 

 t Flora antarctica, p. 97. 



