66 0^ GENERA AND SPiil'lES. 



less distance apart, and in an alternate manner on the sides 

 of the progressing- axis, the foot or base of attachment of 

 the frond forming with the node a distinct and well marked 

 articulation or joint, which ultimately becomes the point of 

 separation of the mature frond, the node remaining per- 

 manont in the form of a round more or loss elevated 

 cicacrix. This mode of growth includes all F(jlypodiacea>, 

 as restricted hj me to the tribes Oleandrcp, BavalUce, Poly- 

 podece, and Platycerecc. To this mode of g-rowth I have 

 given the name Eremohrya, and in characterising the genera 

 the words vernaAion articulate are employed, and the pro- 

 gressing axis from which the fronds are developed suroiilum. 

 The number of species referable to Eremohrya, however, 

 are few in comparison with those which possess a very 

 different mode of growth. If, for example, a plant of 

 Lastrea FLlix-mas be examined, the fronds will be found to 

 be successively produced in a spiral manner from the apex 

 of the stem, in the form of a corona or crown, and thus by 

 successive development the stem is increased in height. 

 All Ferns developing fronds in this manner, even the 

 smallest, the axis of which does not rise above the ground, to 

 lofty tree Ferns, belong to this division as also a numerous 

 class which produce fronds similar to the above, but which 

 form a decumbent stem Ijang on the ground or but slightly 

 inclined upwards. This I term vernation fasciculate decum - 

 hsnt, and the preceding vernation fascKidate erect. Another 

 mode of growth is common to many Ferns, such for 

 example in Pteris aquiliiia, La,strca serra, Polybotrya ostnun- 

 dacea, the fronds are normalty produced alternately, in a 

 sino'le series, from the apex of a decumbent or creeping- 

 stem (sarmeutum). In .some cases this mode of growth 

 resembles that of Eremohrya, but from which it is quite 

 distinct, and is readily kno-^vn hy the vascular structure of 



