CHAPTER XXXV. 



SCHIZAEACEAE. 



THIS family includes Lygodium, Schizaea, Aneimia, and Mohria of living 

 genera, with about 80 species, of wide distribution, but chiefly within the 

 tropics. The fossil genera Senftcnbergia Klukia, and perhaps Kidstonia, 

 referred to this affinity, indicate that the Schizaeaceous type was of early 

 occurrence. Whereas in the Osmundaceae, and in the Marattiaceae with 

 few exceptions, the radial type of shoot prevails, in the living Schizaeaceae 

 there is a pronounced leaning towards a dorsiventral habit. The radial 

 type of construction appears in Schizaea, in Mohria, and in most species of 

 Aneimia : frequently, however, the stock is not upright in position, but more 

 or less oblique, while in Aneimia ( Aneimiorrhiza] the stock is a creeping 

 one. The extreme case is in Lygodium, which has a creeping underground 

 rhizome with bifurcate branching, and it bears the leaves inserted in a single 

 row, or it may actually be two nearly coincident distichous rows, upon its 

 upper side. The arrangement of the leaves is, however, in a dense spiral in 

 those cases where the axis is upright or oblique, while in the creeping 

 Aneimias it is in two alternating rows. It is probable in this family, as 

 in others, that the dorsiventral is the derivative and the radial the primitive 

 type ; but it will be seen that Lygodium, which departs most markedly from 

 the radial construction, is in certain other respects relatively primitive. 



The leaves show great diversity of detail in the different genera. In 

 Schizaea there is a very marked and repeated dichotomy (Fig. 300) : the 

 branches may be more or less completely webbed together below, and they 

 bear the fertile segments on their distal ends. In Lygodium also the leaf- 

 architecture is traced by Prantl to repeated dichotomy, 1 but complicated by 

 the continued apical growth and sympodial development of the branches : the 

 leaf may attain a length of 100 feet or more. This extraordinary foliar 

 structure acts as a prehensile climber, and the fertile segments are seated on 

 the distal ends of the branched pinnae which it bears at intervals. In 

 Aneimia and Mohria the leaves are less complex, and the ultimate reference 



1 Die Schizaeaceen, Leipzig, 1881. 



