122 CLASS XXII. ORDER I. 



involucre, when a little opened, is strictly peltate.) 

 55. 5. Frond tern ate — crucitarium^ (shield- 

 fern) leafets pinnaiifid. — Frond pinnate with 

 UNDIVIDED LEAFETS— acros^ic/roi^/fs, Icafcts ciliatc- 

 serrate. Frond pinnate with pinnatifid 

 LEAFETS — noveboracensiS) divisions of leafets sub- 

 entire ciliate obtusish — cristatiun^ divisions of leaf- 

 ets tooth-serrate obtuse. Frond doubly-pinnate. 

 '^elixmas'i leafets serrate. Var. erosum^ leafets 

 erose-serrate — marginale^ leafets crenate decurrent. 



Athyrium. (Taken from aspidium.) Capsules 

 in scattered roundish or oblong spots on various 

 parts of the whole lower surface of the frond : in- 

 volucre a rouRdish membrane fastened to the frond 

 at one side of the fruit-dot and opening on the oth- 

 er. (The involucre is generally fastened inwards 

 and opens outwards towards the margin of the 



frond.) 55. 5. Frond pinnate thelyfiteris^ 



(snuff-box fern) divisions of leafets acute. Frond 

 doubly-pinnate, leafets doubly-serrate — -fe* 



lix-femina^ fruit-dots strait- oblong asfilenoidesj 



fruit-dots lunulate. Same, with leafets ser- 

 rate bulbiferum^ leafets opposite, fruit- dots 



round. Same, with leafets notched or tooth- 

 ed — tcnue^ leafets decurrent, toothed — rufidulmn^ 

 leafets crenate with united bases, chaff-bristly be- 

 neath. 



DicKsoNiA. Capsules in small round scattered 

 fruit-dots at the margin of the frond : involucre 

 double ; one part is formed of the thin margin of 

 the frond turned over upon the fruit-dots, the other 

 is from the frond inward side of the fruit-dots, each 

 part opening opposite to where it is fastened to the 

 frond. 55. 5 — pilosmscula^ (fine-haired fern) frond 

 doubly-pinnate, leafcls pinnatifid. 



Woodsia. Involucre perianlh-form, with a hairy 

 margin : capsules pedicclled included within the 



