CHAPTER XXVII 



HYPODERRIS, Brown. 

 (Hyp-od-er'-ris.) 



F this genus only two species are known ; they are closely 

 allied to Woodsia, but may be distinguished at first sight by 

 their comparatively large size and robust habit, and botanically 

 by their having a conspicuously-reticulated venation. In 

 Hooker's " Synopsis Filicmn " Hypoderris forms Genus 10, 

 and is placed between Onodea and Woodsia. The name is derived from 

 hyi^o, under, and derris, skin, in reference to the indusium (covering of the 

 sporangia), a portion of which is buried under the sori (spore masses). The 

 fronds, produced from a short rhizome (prostrate stem) of a woody nature, 

 are either undivided or three-lobed. The sub-globose sori are disposed in lines 

 or series parallel with the secondary veins, and usually scattered over the 

 whole surface of the under-side of the fronds ; they are furnished with a 

 membranous, parchment-like involucre in the form of a calyx and fringed 

 on the margin. 



Culture. 



The Hypoderrises are Ferns of easy culture, thriving well in a warm 

 temperature and moist atmosphere. The compost which they prefer consists 

 of one part of fibrous loam, two of peat or partly-decayed leaf-mould, and 

 one of silver sand ; and although attaining larger dimensions when grown 



