CHAPTER XXX, 
SCHIZAEACEAE. 
Tus 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 Senftenbergia Klukia, and perhaps Kvdstonia, 
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 Amecmia (§ 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 arranggment 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 Zygodzuwm, 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 ZLygodium also the leaf- 
architecture is traced by Prantl to repeated dichotomy,! but complicated by 
the continued apical growth and sympodial development of the branches: the 
leaf may attain a length of too 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. 
