90 I<EAFI<BTS. 



northeastern seaboard, such as were indicated by me in the 

 Ottawa Naturalist (1909), vol. xxiii, pp. 17-19. 



Thawctrum leiophyllum. Plants very large, the scapes 

 6 to 9 inches high, the leaves erect, some of them 4 inches 

 high including the long firm petiole ; leaflets 9 to 17, glaucous 

 on both faces, hardly less so above than beneath, also both 

 faces devoid of notable venation and very smooth, of remark- 

 ably thin texture, even those remaining over from the pre- 

 ceding season hardly more than firm -membranaceous, nearly 

 all broader than long and all lightly but evenly and distinctly 

 crenate-lobed ; pedicels almost filiform yet rather wiry, wholly 

 curved and gradually so bearing the fruits at a distance from 

 the rachis, or occasionally almost pendulous : mature carpels 

 1 to 4, short and thickish, not strongly oblique at summit, 

 also rather lightly ribbed. 



Denizen of open bogs at much lower than alpine stations 

 in southern Wyoming. The specimens before me are, first 

 of all, such as were collected by Elias Nelson, in Chimney 

 Park, 1 Aug., 1901. These, which I name as typical, are 

 from the herbarium of the University of Wyoming as a loan. 

 All these are in nearly or quite mature fruit. The characters 

 of the almost white-glaucous leaves of such very thin texture 

 and with only a delicate and inconspicuous venation suffice to 

 mark this as specifically distinct from other Rocky Mountain 

 plants of its kindred which have whitish yet quite coriaceous 

 and roughly veiny leaflets, all of which are also of cold dry 

 alpine heights. At substantial agreement with these Nelsonian 

 specimens are two sheets in the same herbarium gathered by 

 Mr. Geo. E. Osterhout, in Big Creek Park, Wyoming, one 

 in July, 1896, the other in the same month of 1898. 



Out of the 12 good specimens thus at hand, 11 are wholly 

 pistillate. The other has a few stamens accompanying the 

 pistils ; and these show an excellent character in the anthers, 

 for these are uncommonly long and linear, as well as 'very 

 blunt and pointless at apex. 



The species the descriptions of which are next subjoined 



