362 PERN FAMILY. 



§ 9. Pruit-dots separate or laierally confluent at or near the margin of the frond, 

 borne on the ends of the veins, or on the ends of very short side^einleis: the 

 indusium attached at the base or base and sides, and opening toward, ike mar- 

 gin of the fruitful portion of the frond. 



20. DAVALLIA. Indiisium of a single piece, flattish or often convex and shaped 



like half a goblet cut lengthwise. Exotic Ferns, mostly decompound. 



21. DICKSONIA. Indusium united by its sides with a little lobe or tooth of the 



frond, forming a minute 2-lipped cup, at first nearly or ijuite closed, opening 

 as the spore-oases ripen. Large Ferns, native or exotic, some of the latter 

 arborescent. 



II. CYATHEACE^, or TREE FERNS : with erect and tree- 

 like stems, often many feet high. Fruit-dots round, not marginal, 

 naked, or with an involucre placed beneath the stalked spore-cases, 

 which are seated on a globose or elevated receptacle, have a some- 

 what oblique complete ring, and burst open transversely. 



22. CYATHEA. Fruitdots on a vein or in the forking of a vein, at first enclosed 



in a globose involucre, which opens at the top, and remains cup-shaped with 

 an entire or broken edge. 



23. ALSOPHILA. Fruit-dots as on the last, but entirely naked, or with a rudi- 



mentary indusium consisting of a minute scale beneath the spore-cases: 

 veins free. 



III. HYMENOPHYLLACEiE, or FILMY FERNS: these 

 have very delicate and translucent fronds, the short-pedicelled spore- 

 cases growing on a short or long thread-like receptacle, included in 

 a goblet-shaped or 2-lipped involucre, and furnished with a complete 

 transverse or slightly oblique ring. 



24. TRICHOMANES. Fruit-dots marginal, at the end of a vein, which extends 



through the funnel-form or goblet^shaped involucre, as a thread-like recepta^ 

 cle bearing the spore-cases ; involucres sunken more or less in the frond, and 

 of the same pellucid texture. 



IV. SCHIZ^ACE.S; : mostly small Ferns, or else with climb- 

 ing fronds. Spore-cases ovate, sessile, having a complete transverse, 

 articulated ring or cap at the apex, and opening by a longitudinal 

 slit. 



* Ferns with elegant climbing fronds, rising from slender creeping rootstochs: spore- 



cases fxed by their side. 



26. LYGODIUM. Pinnae or frondlets in pairs. Spore-cases covered by imbri- 

 cating scale-like indusia in a double row on narrow lobes of the frond. 



• » Not climbing: rootstoch short : fronds clustered: spore-cases fxed by their base: 



no indusium. 



26. ANEIMIA. Spore-cases on the narrow panicled branches of the lowest pair of 



pinnag of the 1-3 pinnat« frond, or on separate fronds. 



27. SCHIZiEA. Spore-cases in a double row on the narrow divisions of a pinnate 



or rarely pedate special appendage to the simple and linear, or fan-shaped, 

 and sometimes many-forked frond. 



V. OSMUNDACE^, or FLOWERING FERNS: rather large 

 Ferns ; the spore-cases covered with reticulated ridges, opening 

 longitudinally into two valves, and with no ring, or a mere vestige 

 of a transverse ring at the back. 



28. OSMUNDA. Eootstock very thick, creeping, the growing end producing a 



crown of tall showy fronds. Fertile fronds or parts of fronds contracted, 

 pinnately compound, the narrow often thread-like divisions densely covered 

 with nearly sessile spore-cases. 



