A Synopsis of Plant Phyla 43 



Family 54. Hypnaceae. Mosses of variable size antl habit, 

 with costate or ecostate leaves, which are in two or many rows ; 

 capsule long-stalked, horizontal or nodding ; peristome double, 

 of 16 outer, and as manv inner teeth. Hxpintm, Amblystcgiinn, 

 (Pf. I. 3,'-.) 



Phylum IX. PTERIDOPHYTA. The Ferns. 



Chlorophyll-green, mostly terrestrial plants, exhibiting two 

 generations in each life cycle, viz., (i) the gametoph\te, which is 

 small and short lived, and (2) the sporophyte, which is large, 

 with roots, stems, and leaves, and long-lived. Stems of the sporo- 

 phyte solid, erect or creeping; leaves usually relatively large, with 

 broadly expanded blades and elongated petioles. The name 

 Pteridophyta is here restricted to the ferns, alone (Filicinae), 

 the horsetails and lycopods having been removed to separate 

 phyla. 



Class 20. EUSPORANGIATAE. Sporangia developed from 

 internal cells. 



Order Ophioglossales. Gametophyte tuberous, chlorophyl- 

 less, subterranean ; sporophyte with large, often compound sporo- 

 phylls (leaves), certain branches of which are spore bearing. 



Family i. Ophioglossaceae. Stems short, erect, bearing one 

 or few leaves. Ophioglossitm, Botrychium. (Pf. I, 4, 449.) 



Order Marattiales. Gametophyte flat, chlorophyllose. at- 

 tached with rhizoids ; sporophyte with large, compound sporo- 

 phylls borne upon a mostly upright stem, which is rooted below ; 

 sporangia hypophyllous. 



Family 2. Marattiaceae. Large, tropical ferns of a type now 

 nearly extinct. Angiopteris, Maratiia, Danaca. (Pf. I, 4, 422.) 



Order Isoetales. Gametophytes dioecious, the male rudimen- 

 tary, one-celled, very small; the female larger, many-celled, but 

 little larger than the megaspore. Sporophyte with an erect 

 stem bearing many crowded, narrow sporophylls ; sporangia 

 epiphyllous. 



Family 3. Isoetaceae. • ^Medium-sized to small aquatic plants 

 with a rush-like aspect, the sporangia sunken in the upper tissues 

 of the leaf-bases. Isoctcs. (Pf. I, 4, 756.) 



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