CHAPTER VIII 



MARATTIALES 



The Marattiace^ 



The Marattiacese, the sole existing family of the order, at the 

 present time includes five known genera, with about twenty- 

 five species of tropical and sub-tropical Ferns. Many fossil 

 types are known which evidently were related to the Marat- 

 tiacese, and they seem to comprise the majority of the Palaeo- 

 zoic Ferns. 



Recently a good deal of attention has been paid to these 

 Ferns, and our knowledge of their life-history and structure is 

 fairly complete. Some of them are plants of gigantic size. 

 Thus the stem of Angioptcris cvecta is sometimes nearly a metre 

 in height and almost as thick, with leaves 5 to 6 metres in length, 

 and some species of Maraffia are almost as large. The other 

 genera, Kaiilfussia, Archangiopteris and Dancua, include only 

 species of small or medium size. While in the structure of the 

 tissues and the character of the sporangia these show some 

 resemblances to the Ophioglossacese, their general appearance is 

 more like that of the true Ferns, with which they also agree in 

 the circinate vernation of their leaves. The sporangia are borne 

 upon the lower surface of ordinary leaves, as in most lepto- 

 sporangiate Ferns, but the sporangia themselves are very differ- 

 ent, and are more or less completely united into groups or 

 synangia, which open either by longitudinal slits or, in Dancea, 

 by a terminal pore. The base of the leaf is provided with a 

 pair of fleshy stipules, which possibly correspond to the sheath 

 at the base of the petiole in Bofrychmm. 

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