Holm, The genus Carex in North -West America. 23 



would, thus, appear as if our region represents on old geographica! 

 Center for some of the Stenocarpae with the fundamental types still 

 in existence. Besides these species four others occur, also, in 

 America viz: C. petrieosa (Alberta), C. gynodynama and luzullna 

 (California) and C'. juncea (North Carolina). 



Carices lamiwochlaenae and elynanthae contain no speciea 

 which may be considered as type of our region. 



Carl ces sphaeridi op h o rae. 



Only a few species are represented in our region, but never- 

 theless \ve meet here with the monostachyous C. scirpoidea of which 

 the var. stenochlaena is only known from here; furthermore the 

 formae centrales with C. verecunda and the more evolute C. globosa, 

 besides the peculiar C. Whitneifi of the desciscentes. Of these C. 

 verecunda {C. inops Bail. non. Kze.) is a north-western type, while 

 C. globosa and Whitneyi have, also, been observed farther South, 

 in California. 



Carices trlchoca > 'p a e. 



Of these C. Oregonensis is the only type peculiar to our 

 region. The grex is altogether very scattered throughout the 

 continent, some of the members being characteristic of California 

 (C.hii'tissima and Yosemltana), others of the Atlantic States (C.vestlta, 

 striata etc.^ or of Mexico (C. psllocarpa). Whether C. lanuglnosa 

 be a species distinct from C. filiformis or merely a variety (lati- 

 folla Bcklr.j it is stränge to see the wide distribution on this con- 

 tinent and its absence from the old world, where C. ßiformis is 

 not uncommon. Considering the fact that C. filiformis on this 

 continent is accompanied by several near allies (C. Houglitonii, 

 trichocarpja etc.) and especially by C. lanuglnosa it seems as if 

 North America has been a very important center in regard to the 

 distribution and development of this particular group of species. 



Ca r ices hy m e n o c h l a e n a e. 



Only one of these may be looked upon as a type of our region : 

 C. Krausei, which in several respects seems very closely allied to 

 C. caplllaris. Another near ally is C. Williamsii, but very charac- 

 teristic by its androgynous terminal spike and filiform leaves. The 

 very peculiar C. ampUfoUa is a western t\ pe, of which the geographi- 

 ca! center evidently lies within our region since it seems to be 

 so very rare in California. 



Carices spirostachyae. 



The grex is altogether poorly represented in North America 

 and contains no species peculiar to our region. The Californian 

 C. aequa Clarke does not reach Washington or Oregon, and the 

 formae desciscentes: C. squarrosa, typhina and stenolepls, so very 

 characteristic of the eastern and southern States, do not occur here. 



Carices echinostachyae. 



The species that occur in North-West America are, with the 

 exception of C. microglockm, more frequent in the eastern States, 

 and both C. microglochin and panclflora occur in the old world. 



