THE MALE FERN DRTOPTERIS FILIX-MAS 



(i) var. atlantica v. Tavel n.var. Sori small, up to i mm. wide, frond stiff and very 

 tough — Madeira and Spain. Near this is f. Merinoi Christ {Bull. Acad. Int. Geogr. hot. Le 

 Mans, no. 172, 1904) in Spanish Galicia. 



(2) var. Duriaei Milde {Fil. Europ. et Atlant. 1867, 123) in Asturias. 



(3) var. insubrica v. Tavel n.var. with large reddish brown indusia, touching each 

 other, fronds a normal green, somewhat hairy — Tessin, south side of the Simplon; 

 Unterwallis near Salvan (Coquoz, Farquet). In addition, conspicuous in the Bergamo 

 Alps (Chenevard), Liguria [Erb. Crittog. Ital. 605) and Corsica (Aellen). With smaller 

 sori also in the Black Forest; Baden-Baden (M. Lange) and Zastlertal (Losch). 



(4) var. disjuncta Fomin (Moniteur, Jard. Bot. Tiflis, xx, 27, 1911). The most highly 

 developed form which has split indusia the most frequently — Tessin; Upper Rhone 

 (Oberholzer) ; Black Forest (Christ, Losch); Vosges (Walter); Caucasus (Fomin). f. 

 paleaceolobata (Moore) {Oct. Nat. -print. Ferns, i, 195, pi. 33 C). Segments of the lower 

 pinnae incised — Tessin; Upper Rhone (Oberholzer); England; Channel Islands; 

 Scotland, 



(5) var. pumila (Moore) {Ferns of Great Britain and Ireland, pi. 17 B, 1855). Alpine 

 dwarf form with glandular indusium. Sori in a single row — Wales. South side of the 

 Simplon ; Tessin, in part in transition forms to var. insubrica. 



(6) var. rubiginosa Fomin, loc. cit. 29. Not known with certainty beyond the 

 Caucasus. 



(7) var. melanothrix v. Tavel n.var. Leaf texture soft, with a dense indumentum 

 composed of long patent black filamentous scales mixed with colourless lanceolate 

 ones. Indusia small, black. Dillingen in the Saar (W. Freiburg). 



II. Related forms with the habit of the first group, but with the deciduous fiat 

 indusium found in Dryopteris Filix-mas. 



(8) var. ursina (W. Zimmermann) {Allg. Bot. ^. 22, 1916). Parallel form to var. 

 insubrica, differing in the indusium. This is the form which is generally referred to as 

 var. subintegra, but this name also includes var. disjuncta and other forms when used by 

 Doll and Christ. — Widely distributed in the Alps in woods up to 1700 m. (Davos) 

 also in the Black Forest and the Vosges. Near to this is f. aurea v. Tavel f.n. apparently 

 a subalpine handsome form of yellow-green colour — Upper Rhone (Oberholzer) ; 

 Bernese Oberland; Pont de Nant (Wirtgen). 



(9) var. pseudodisjuncta V. Tavel n.var. Habit of var. disjuncta, indusia ofZ). Filix-mas 

 — central Switzerland (Oberholzer) ; Bernese Oberland. 



(10) var. tenuis v. Tavel n.nom. (syn. var. subintegra Fomin, loc. cit. 29. Aspidium 

 Filix-mas var. subintegrum Doll. p.p. Christ p.p.)- Spores in Swiss material partly aborted 

 (Oberholzer). — Upper Rhone (Oberholzer); neighbourhood of Bern; Schaffhausen 

 (Kummer) ; neighbourhood of St Gallen. 



(11) var. robusta v. Tavel n.var. In various ways intermediate between D. Borreri 

 and the different varieties of Z). Filix-mas, with the leaf texture and hairs of the first and 

 the pinnule shape and indusium of the second. Possibly hybrids between the two but 

 fertile. — With the two parent species in mountain woods. Upper Rhone (Oberholzer) ; 

 Bernese Oberland; Unterwallis (Coquoz); Black Forest, Hirschsprung (Losch).' 



One of the principal reasons for the very large number of apparently true-breeding 

 varieties and forms within D. Borreri undoubtedly is the persistent apogamy of the 

 species. Any morphological variant produced by mutation, hybridization or other 



56 



