Classification of Pla7its 



233 



easily be mistaken for a grass. The frond or leaf is just a wiry 

 stalk with very small comb-shaped lobes at the top. 



Unlike so many ferns which thrive best in shady ravines, it can grow 

 in very dry, hot situations. It is found on mountain tops and down nearly 

 to the sea level. 



Gleichenia may be distinguished from all other South 

 Africa ferns by the dichotomous branching of the fronds. In 

 the Knysna forests it climbs gracefully up the banks, ten or 

 twelve feet high. 



Hemitelia capensis, Br., the tree fem, the most beauti- 

 ful fern in .South Africa, extends from Table Mountain to 

 Natal. 



Pteris aquilina, f^. grows commonly on hills. 



I. 



II. 



III. 



Fig. 207. — Pinnae of fern leaves. I. Aspidunn u ith :i single sorus ; the 

 spore cases may be seen around the edge of the indusium. II. Asplcuiiaii with 

 several sori. III. A young fern plant growing from the heart-shaped prothal- 

 lium. (From Thomt? and Bennett's " Structural and Physiological Botany ".) 



The spore cases of Pleris are continuous along the margin 

 of the leaf, which is folded over to protect them. 



Lomaria capensis, Willd., a large coarse fem with rope- 

 like spreading stems, miy be known by the whole under surface 

 of the fertile fronds being covered with fruit-dots. 



Hymenophyllum and Trichomanes are found in deep 

 ravines, washed by the spray of waterfalls. The beautiful little 

 fronds are almost transparent, and the delicate creeping stems 

 are like threads. The spore-cases are clustered on a stalk, en- 

 closed in a tubular or cup-shaped indusium. The indusium 

 of Hymetiophyllum is deeply two-loped. That of Tj-iikomanes 

 is not slit, and the fronds are less divided. 



