XL] 



PERANEMA 



107 



Fig. 651..-/ = mature sporangium of Diacalpe, showing a 

 hairborneon the three-rowed stalk. i5 = vertical section 

 through a sporangium, showing the rugged spores, the 

 annulus and stomium. (After Davie, x 150.) 



Peranema Don 



The genus Peranema includes a single Himalayan species, P. cyatheoides 

 D. Don. This Fern was first collected by Wallich, and described by Don in 

 1825 under the above name. But Wallich also described it in 1830 under 

 the name SpJiaeropteris barbata Wall.: naturally the older name must stand. 

 Its further vicissitudes of name and classification have been summarised by 

 Davie {I.e. p. 245): here it will suffice to say that it has now definitely taken 

 its place in the Woodsieae under its original designation. 



Peranema has an upright stock some 4-6 inches long, bearing bright 

 green leaves 1-3 feet in length, both stock and rachis being covered with 

 red chaffy scales. The leaves are tri-pinnate, with glandular hairs: the 

 venation is open. The stalked sori arise superficially at some distance from 

 the vein-endings. Each sorus is spherical, and is covered by an indusium 

 that is entire, except for a small gap on the side next the leaf margin, close 

 to the insertion of the stalk. At maturity the indusium splits across, its two 

 sides becoming reflexed and finally flattened. The very numerous sporangia 

 are long-stalked, and crowded upon the convex receptacle, while the annu- 

 lus is slightly oblique. It is apparent that the interest will centre in the 

 pecuHar soral condition (Fig. 650, E, H). 



