26 Our Native Ferns. 



CHAPTER II. 



MORPHOLOGY OF THE GROWING FERN. 



Pour bicn aavoir une chose, il faut en eavoir lea details. 



— La Rochbfottcatjld. 



24. Every one familiar with the forest and its products must 

 have seen the young ferns unroUing from the bud in spring 

 and early summer. It will be noticed that the fronds are coiled 

 from the apex to the base, and form crosiers, so called from their 

 resemblance to the head of a bishop's staff. This method of ver- 

 nation is called circinate, and is rarely found except among ferns. 

 In the grape-ferns and adder -tongues, the vernation is straight or 

 merely inclined, thus approximating that of ordinary flowering 

 plants. 



25. Rhizoma. — Ferns usually spring from an underground 

 stem called the rhizoma or rootstock. This may be simple or 

 branched, smooth or scaly, horizontal, oblique, or even vertical. 

 In some ferns it is fine and hairlike, while in others it is very large 

 and stout. In some cases the rhizoma creeps at the surface of the 

 ground and even rises above it, as in the variety of Aspidium con- 

 terminwn recently discovered in Florida. In the tree ferns of 

 warmer climates it often forms a trunk fifty feet high bearing 

 the fronds at the summit when it takes the name of caudex. 



26. Frond. — The aerial portion consists essentially of a leaf- 

 stalk and blade ; the former is technically called the stipe, and the 

 latter the/rond. Though these are usually distinct from each other 

 in appearance, the stipe is sometimes wanting, and in others no 

 distinction can be made between them. Both stipe and frond, or 

 either one, may be glabrous (smooth), pubescent (softly hairy), 

 hairy, woolly or scaly. When the scales are small and somewhat 

 appressed, the surface is said to be squamous. In a few of our 

 native ferns the under surface is covered with a white or yellow 

 powder bearing some resemblance to flour or corn-starch. For this 

 reason a surface of this character is called farinaceous. Such is 

 the California gold-fern or "golden back" {Gymnogramme trian- 

 gularis), and several of the cloak-ferns {Notholcena), and such are 

 the various gold and silver ferns of conservatories, including some 

 of the richest and most beautiful in the world. 



27. The frond may be simple when it consists of a single un- 

 divided leaf, or compound when it is divided into segments. The 



