PEEANBME^. 01. 



receptacles medial or terminal. Involucre soft, membranaceous, 

 pateriform and fimbriately crinite, or calyciform with the margin 

 lobed, or sub-globose with a contracted mouth. Veins simple 

 forked or pinnate, from a central costa ; venules free. 



Fronds membranaceo-herbaoeous, small, pinnate pinnato- 

 pinnatifid or bi-piunate. Rhizome tufted, erect or decumbent. — 

 A very well-marked group, distinguished by the involucriform 

 nature of the indusium, the sessile sori, and free veins. There is 

 some apparent difference between the involucres of the two 

 extreme sections, but these seem sufficiently reconciled by the 

 intermediate group ; and Wbodsia proper, may be regarded as 

 haying the sub-globose involucre of FhysemaUtim split at the 

 margin into criniform incurved segments ; thus retaining, in 

 some measure, the cup-shaped character. 



§ Woodsia. — Involucres minute pateriform, tiie margin incurvo-crinite. 

 Ex. : W. ilvensis, B. Br. I W. alpina, Gray. 



W. glabella, .8. Br. \ W. pUosella, Sujirechf. 



§ Terrvnia. — Involucres sub-liemi8plierical irregularly-lobed. 

 Ex. : W. obtusa, Torrey. | W. inciaa, Wllies. 



§ Physemajtiwm. — Involucres sub-globose witb a contracted apical mouth. 

 Ex. : W. moUis, J. Sm. J W. peruviana, Hook. 



W. fragilifl (Dicksonia, Trev.; Hymenocystis caucasica, Meyer, J 



(b) Veins reticulated. 



143. HYPODEKRIS, B. Brown, in Wall. PI. Asiat. Sar. 

 i., 16 (note). 



Woodsia sp., Mettenius. 



Sori involucrate, globose ; the receptacles compital, i.e. situ- 

 ated at points where several reticulated veinlets join. Involucre 

 membranaceous, calyciform, fimbriate at the margin. Veins pin- 

 nate from a central costa, prominent ; venules compoundly anas- 

 tomosing in about three series of unequal areoles, within the 

 ultimate of which are produced free divaricate sterile veinlets. 



Fronds herbaceous, simple or three-lobed. Sori uniserial on 

 each side the veins, more scattered towards tlie margin. Invo- 

 lucres obscure. Khizome creeping.^Distinguished from Woodsia 

 by the reticulated venation only. We take the recognition of 

 such genera as Bypoderris, and DictyoxipMum, by botanists who 



