28 PHYSIOGNOMY OF PLANTS. 



shaded over-arching walks or avenues. The smooth. polished 

 and often lightly- waving and bending stems of these tropical 

 grasses are taller than our alders and oaks. The form of 

 Graminese begins even in Italy, in the Arundo donax, to 

 rise from the ground, and to determine by height as well as 

 mass the natural character and aspect of the country. 



The form of Ferns, ( 28 ) as well as that of Grasses, becomes 

 ennobled in the hotter parts of the globe. Arborescent ferns, 

 when they reach a height of above 40 feet, have something 

 of a palm-like appearance ; but their stems are less slender, 

 shorter, and more rough and scaly than those of palms. 

 Their foliage is more delicate, of a thinner and more trans- 

 lucent texture, and the minutely indented margins of the 

 fronds are finely and sharply cut. Tree ferns belong almost 

 entirely to the tropical zone, but in that zone they seek by 

 preference the more tempered heat of a moderate elevation 

 above the level of the sea, and mountains two or three 

 thousand feet high may be regarded as their principal seat. 

 In South America the arborescent ferns are usually found 

 associated with the tree which has conferred such benefits 

 on mankind by its fever-healing bark. Both indicate by 

 their presence the happy region where reigns a soft perpetual 

 spring. 



I will next name the form of Liliaceeous plants, ( 29 ) 

 (Amaryllis, Ixia, Gladiolus, Pancratium) with their flag-like 

 leaves and superb blossoms, of which Southern Africa is the 

 principal country; also the Willow form ( 30 ), which is indi- 

 genous in all parts of the globe, and is represented in the 

 elevated plains of Quito, (not in the shape of the leaves but 



