68 MY LIFE [Chap. 



was with Dufour at St. Sever, in April, 1846, he received 

 a large parcel of plants recently gathered in the Sierra 

 Guadarama by Prof. Graells, of Madrid. A very large pro- 

 portion were aromatic, and many of them Labiates. 



" I cannot make out that plants with scented leaves 

 abound more in the tropics than in mid-Europe : nor does 

 there seem to be a larger proportion of them in any zone of 

 the equatorial Andes than in the Amazonian plain ; although, 

 as hill-plants are often gregarious, and those of hot plains 

 very rarely so, odoriferous plants may seem more prevalent 

 in the high Andes than on the Amazon. 



" Plants growing nearest eternal snow in the Andes are, 

 however (so far as I have observed them), all scentless ; but 

 some acquire an aroma in drying, as, for example the thick 

 roots of the Valerians that abound there. 



"Aromatic plants grow in the Andes up to, perhaps, 

 13,000 feet, and consist chiefly of Composites, Myrtles, 

 Labiates and Verbenas. I know a hill-side at about 9000 

 feet, which at this time of year is one mass of odori- 

 ferous foliage and flowers, chiefly of a Labiate undershrub 

 (Gardoquia fasciculata, Bth.). Another slope of far wider 

 extent is much gayer with varied colour mainly of the blue 

 flowers of Dalea Mutisii H. B. K. — a papilionaceous shrub 

 allied to the Indigos — and of the red-purple foxglove-like 

 flowers of Lamourouxia virgata H. B. K. (which is parasitic 

 on the roots of the Dalea) mingled with the yellow flowers of 

 the Quitenian broom {Genista Quitensis, L.), and of many 

 other herbs and shrubs with flowers of various shades of 

 colour ; but aromatic plants are almost unrepresented 

 except by scattered bushes of a Salvia and a Eupatorium. 

 Analogous contrasts are common enough in our own country. 



"In those parts of the Peruvian and Quitenian Andes 

 I have explored, I have not found odoriferous plants more 

 abundant than in some parts of England and the Pyrenees ; 

 yet they are quite as much so as in the Amazonian plain, 

 and often belong to the same Natural Orders. Now leaf- 

 cutting ants are unknown in the Andes ; whence I infer that, 

 although the presence of a pungent smell and taste may be 



