v] FERNS 11 



that constant attention is necessary to keep it from 

 invading newly opened country (45). On Mount Ophir 

 in the Malay Peninsula the cosmopolitan bracken 

 occurs in association with the two genera Matonia 

 and Dipteris, ferns which are among the most striking 

 examples of links with a remote past and have a 

 restricted geographical range. With Osmunda re- 

 galis, the Royal Fern, the Bracken is conspicuous 

 in the marsh vegetation of the Bermudas ; it flourishes 

 on the Atlas INIountains, in the Canary Islands, in 

 Abyssinia, on Mt Kenia, in British East Africa, in 

 the Himalayas, and is in fact generally distributed in 

 the tropics in both the north and south temperate 

 zones. 



The Royal Fern (Fig. 9) is another British species 

 with a wide distribution ; it occurs in Northern Asia 

 and in North America ; it is common in the Siberian 

 forests and lives in several tropical countries, ex- 

 tending to Southern India and Cape Colony, and in 

 South America it is represented by a closely allied 

 species. Though at the present day Osmunda regalis 

 is one of the rare English Ferns, its occurrence in the 

 submerged forest-beds round our coasts and in pre- 

 Glacial beds points to its former abundance in the 

 British area generally. The Royal Fern is a member 

 of a family now represented by two genera, Osmunda 

 and Todea. 



With the exception of Todea harhara, with its 



