Part II. THE MARATTIALES. 



The members of the second order of the Eusporangiatae — the Marattiales — 

 resemble quite closely the typical Leptosporangiatae. Both in the form and venation 

 of the leaves and in the development of the sporangia upon their lower surface they 

 recall the common ferns. But the structure of the sporangium is very different, 

 and both in its structure and development the sporangium shows certain evident 

 resemblances to that of the Ophioglossacese. 



The Marattiaceous type is a very old one, and this fact lends a special interest 

 to these few survivors of the ancient Paleozoic fern flora. Like the Ophioglossaceae, 

 the leaves of the Marattiaceae are thick and fleshy in texture, but usually firmer than 

 is the case in the Ophioglossaceae. Some of the smaller species of Dancea are only 

 2 or 3 decimeters in height, but the larger species of Marattia and Angiopteris are 

 among the largest of the ferns. The latter, which is common in the eastern tropics 

 and extends to Australasia, is a noble fern whose great caudex, covered with the 

 persistent leaf bases, is nearly as big as a barrel, and the gigantic leaves reach a 

 length of 5 or 6 meters, with stalks almost as thick as a man's arm. In the dense, 

 wet forests of Tjibodas in Java, for example, the development of this fern is espe- 

 cially luxuriant, and groups of them form one of the most striking features of this 

 rich, tropical flora. 



The Marattiaceae frequent, for the most part, the moist, shady forests of the 

 tropics, where they form a characteristic feature of the vegetation. Along the steep 

 banks of moist, shady ravines or streams they sometimes occur in profusion. 



The number of living Marattiaceae* is small, some authorities recognizing 

 only about thirty species. There is, however, a good deal of diff"erence of opinion 

 as to the number of species in some of the genera. This is especially true of 

 Angiopteris, which many authorities consider to have only one single, extremely 

 variable species, while others recognize many species. One of the genera, Marattia, 

 is widespread throughout the tropics of both hemispheres, where there are about 25 

 species. (See Bitter 1, Christensen 1.) One of these, M. douglasii, extends to the 

 Hawaiian Islands, where it is a common and conspicuous fern. Angiopteris is 

 widespread throughout the tropics of the old world and reaches beyond the tropics 

 into Australia and southern Japan. Archangiopteris, with a single species, A. 

 henryi, is a recently discovered form occurring in southwestern China. Kaulfussia, 

 also a monotypic species, occurs throughout the Indo-Malayan region and extends 

 as far as the Philippines. The genus Dancea is exclusively neo-tropical and com- 

 prises about 20 to 25 species, most of which occur in the West Indies, northern 

 South America, Central America, and Mexico. A sixth genus, Macroglossum, from 

 Borneo, has recently been described (Copeland 1). 



Of these, Kaulfussia is the most aberrant, diff"ering markedly from the other 

 genera in the form and venation of the leaves, as well as in the shape and position 

 of the synangia. Kaulfussia and most species oi Dancea have dorsiventral rhizomes, 

 while the other genera have an upright, radially-constructed caudex. 



The gametophyte, in all of the investigated species, is a large, dark-green, 

 fleshy thallus, much resembling superficially such a liverwort as Pellia. The re- 

 productive organs are very much like those of Ophtoglossum, and chlorophyll is 

 formed in abundance in the gametophyte. The large liverwort-like gametophyte 



* Christensen (l) recognizes 62 species of Angiopteris^ i of Archangiopteris, 26 of Danaea, i of Kaulfussia, and 28 of Marattia. 



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