250 Floristik, Geographie, Systematik etc. 



into several sections. In the first section a general description of 

 the genus is given in comparison with other genera like Diplaaium 

 and Asplenium. The other sections deal with forms which belong 

 to A. Filix femina or are allied to this species. 



In the eastern United States and Canada there are two 

 distinct species of Athyrium, neither of which is conspecific with 

 A. Filix femina of Europe. One of these two species A. asplenioides 

 (Michx) Desv. is prevailingly southern in its distribution, the other 

 A. angustum (Willd.) Presl, is prevailingly northern. The species 

 are fully discussed and compared with the european species. A key 

 to their determination is added, annotated with details on synonymy 

 and distribution. In A. asplenioides (Michx.) Desv. two forms can be 

 distinguished: f. typicum and f. subtripinnatum form. nov. ; A. angus- 

 tum is divided into f. typicum, var. elatius nov. comb. {Asplenium 

 elatius Link), var. rubellum nov. comb. (A. filix foemina rubellum 

 Gilbert), var. laurentianum var. nov., forma confertum forma nov., 

 forma laciniatum forma nov., forma elegans nov. comb. (Ath. filix- 

 foemina elegans Gilbert). 



The lady ferns of Alaska, Western Canada and the North- 

 western States are conspecific with the european plant, but, in 

 some cases, differ from the common European forms of A. Filix- 

 femina in certain minor points, and are then best regarded as a 

 geographical variety of that species, which is distinguished as var. 

 süchense Ruprecht. 



The lady ferns of California, the Basin Region, and the 

 Southern Rocky Mountains differ more markedly from the Euro- 

 pean plant, but are not clearly distinct from the more northern 

 form, and therefore are best considered as a second, and much 

 more aberrant geographical variety of A. Filix femina. It is named: 

 rar. californicum var. nov. 



A boreal and high alpine fern is found in eastern Quebec and 

 in the alpine areas of western North America. This is a clearly 

 distinct geographical variety of the old world A. alpestre and is 

 named : var. americanum var. nov. 



The second part contains a general description of Botrychium 

 virginianum and its american varieties, with descriptions of new 

 forms, and notes on distribution and synonym}^. A key to the 

 determination of these forms is added at the end. Following forms 

 are mentioned: B. virginianum var. laurentianum var. nov. (Labra- 

 dor, Newfoundland, Quebec, Maine, Michigan), var. inter- 

 medium var. nov. (Nova Scotia, Maine, Vermont, Massa- 

 chusetts, Connecticut, New York, Illinois, Missouri; it 

 occupies a region south of that of the former; var. europaeum 



o 



Angström (Quebec, New Brunswick, New Hampshirei 

 Vermont, New York, Ontario, Montana, British Columbia); 

 a variety occurring in the far western States is var. occidentale 

 var. nov. (Montana, Idaho, Oregon, California); var. meridionale 

 var. nov. occurs in Mexico (Chiapas and in the San Migueleto 

 mountains, Valley of San Luis Potosi). Another mexican plant 

 belonging to this group is B. cicutarium (Savigny) Sw. (Santo 

 Domingo, Mexico, Guate mala, and reported also from Jamaica 

 and Panama). Some notes on the general distribution of the 

 different forms of Botrychium belonging to or related with B. virgi- 

 nianum, are added. The Botrychium virginianum group presents 

 the most complicated arrays of forms in eastern North America, 



