A SPLENI U M. 



481 



others have theirs linear-spear-shaped, and cut down to the rachis (stalk 

 of the leafy portion) at the base ; while the greatest portion of them have 

 their fronds bi- or tripinnate. All have their veins free, and in some of 

 them the sori and involucres extend to both sides. 



Euasplenium (Eu-as-ple'-m-um), Moore. The plants belonging to this 

 section have their veins free, simple, or branched, and the linear or linear- 

 oblong sori are either straight or discoidal (round or disk-like). This being 

 a very extensive section, it is necessary to enumerate the various groups of 

 which it is composed ; all of them are distinct from each other through the 

 divisions of the fronds only. 



I. — A group of plants having fronds quite entire, such as A. ensiforme 

 of Wallich. 



II. — A group with fronds lobed or pinnatifid (cut half-way down 

 to the midrib), as seen in the curious A. attenuatum of R. Brown and 

 A. Hemionitis of Linnaaus. 



III. — A group whose fronds are simply pinnate (only once divided 

 to the midrib). This group embraces numerous species, and shows 

 several sub-divisions as follow : 



A. — Plants with pinnae Jin. to Jin. long, blunt, in most species 

 nearly as broad as long. These are best represented by A. viride 

 of Hudson and A. Trichomanes of Linnaeus. 



B. — A small group of plants with few long and narrow pinnae 

 (leaflets), such as A. septe?itrio?iale of Hoffmann. 



C. — An extensive group of species, with pinna? numerous, 

 linear or linear-oblong, usually ample, and terminating in a blunt 

 point, such as in A. caudatum of Forster and A. marinum of 

 Linnaeus. 



IV. — A group of plants having their fronds bi- to quadripinnate 

 (twice to four times divided to the midrib), such as may be noticed in 

 A. Ruta-muraria of Linna3us and A. cicutarium of Swartz. It contains 

 most of the species with fronds proliferous on their upper surface. 

 Thamnoptekis (Tham-nop'-ter-is), Presl, and Neottopteris (Ne-ot-top 7 - 



ter-is), J. Smith. A small section, composed of plants with fronds ample 

 and entire, showing their veins connected at their apex (summit) by 

 a transverse line situated just inside the margin. 



3 Q 



