268 FILICALES 



1. MARATTIALES. Sporangia from cell complex; prothallus 



flattish, antheridia on both sides, archegonia below. 

 3. OPHIOGLOSSALES. Sporangia from cell complex ; prothallus 

 wholly or partially subterranean, tuberous or cylindrical with 

 sunken antheridia and archegonia; embryo often long sub- 

 terranean. Fertile 1. with branches bearing the sporangia. 

 For further details see next art., I'teridophyta, and the families. 

 Cf. also Nat. Pj?.\ Hooker and Baker, Synopsis Filicnni ; Christensen, 

 Index Filicum (for nomenclature) ; Christ, Die Farnkniitler der 

 Erde, 1897; Bower, papers on morphology and phylogeny in Phil. 

 Trans, and Ann. Bot. of the last 25 years, and Origin of a Land 

 Flora; Seward, Fossil Botany, &c., &c. 



Filicales Leptosporangiatae. The first order of Filicales, grouped 

 as follows : 



Sub-order i. EUF1LICINEA E. Sporangium wall usu. with a 

 special ring or annulus of thickwalled cells, by whose means it opens ; 

 homosporous, with mono- or di-clinous prothalli. 



1. Hytnenophyllaceae: herbs with mesophyll usu. one cell thick, 

 and marginal sori term, on naked veins. 



2. Cyatheaceae: usu. tree or large ferns, with complete and 

 oblique annulus. 



3. Polypodiaceae: usu. herbaceous, with imperfect, vertically 

 placed annulus, not closed at base, rarely absent. 



4. Parkeriaceat:: water ferns, sporangia sol. on anastomosing 

 veins, almost spherical, with perfect, sometimes wanting, 

 vertical annulus, and no true indusium, but inrolled 1. margin. 



5. Matoniaceae: herbs with dichotomous 1., sporangia with 

 complete oblique annulus, grouped at base of umbrella-like 

 indusium. 



6. Gleicheniaceae: herbs with 1. repeatedly dichotomous, and 

 sporangia with equatorial annulus; sori on the veins below. 



7. Schizaeaccae: mostly small herbs with sessile sporangia, with 

 complete annulus at apex, sol. on 1. margin or in axils of bract- 

 like segments. 



8. Osniundaceae: short-stemmed ferns with sterile and fertile 1. 

 and naked sori, sporangia with annulus at one side of apex. 



Sub-order 2. HYDROP1ERIDINEAE. Sporangia usu. many 

 in sori, enclosed in metam. 1. segments or indusium-like covers ; 

 spores of two kinds ; macrosporangia with one macrospore, 

 microsporangia with many. 



i. Marsiliaceae: sporocarps pluriloc.; sori 2 oo in 1. apex, 

 c? and ? mixed ; ? prothallus with one archegonium, S of one 

 veg. cell and 2 antheridia. 



i. Salviniaceae : sporocarps uniloc.; sori unisexual, on special 

 water 1. (Salvinia) or submerged lobes of water 1. (Azolla) ; 

 ? prothallus with a few archegonia, $ as in Marsiliaceae. 

 1. Eufilicineae. These plants with the Marattiaceae are generally 

 known as Ferns. An outline of the general life history will be found 

 under Pteridophyta. 



The fertilised ovum on the prothallus developes directly and with- 

 out any resting period into a fern-plant. There is no intermediate 



