(i68) 



differs in being spicate instead of racemose, while the indi- 

 vidual flowers, instead of persisting, fall away easily and 

 early, perhaps before the fruit is fully matured. 



The only specimens known were found growing in moss 

 below Sixty mile Creek, by J. B. Tarleton, August 3, 1899, 

 no. 175a. 



Family Santalaceae. 



Comandra livida Richards. Dawson (Williams); Lake 

 Bennett (Tarleton). 



Family Caryophyllaceae. 

 Silenc reopens Patrin. Dawson ; Walker Gulch (Wil- 

 liams) ; Ft. Selkirk (Tarleton). 



Silene Williamsii Britton sp. nov. 



Related to S. Mcnziesii Hook. Viscid-pubescent all over ; 

 stem 1-3 dm. high, the slender branches widely ascending. 

 Leaves lanceolate to ovate-lanceolate, sessile, firm, entire, 

 2-3 cm. long, 5-10 mm. wide, acuminate at the apex, nar- 

 rowed at the base; cymes terminal, few-flowered; pedicels 

 filiform, 5-10 mm. long; calyx urceolate, its teeth about 2 

 mm. long, erect, the whole about 8 mm. long; petals 

 scarcely longer than the calyx. 



Dawson, R. S. Williams, July 14, 1899 (type) ; fifty miles 

 above Stewart River (Tarleton). 



Lychnis trijlora R. Br. Stream by West Dawson (Wil- 

 liams). 



Vaccaria Vaccai'ia (L.) Britton. Dawson, introduced 

 (Williams). 



Cerastium arvense L. Lebarge Island (Tarleton). 



Co'astium vulgatum L. Dawson, introduced (Williams). 



Cerastium maximum L. Above Stewart River (Tarleton). 



A/sine borealis (Bigel.) Britton. Dawson (Williams) ; Five- 

 finger Rapids (Tarleton). 



Alsine laeta (Richards.) Rydb. Dawson (Williams) ; White 

 Horse Rapids (Tarleton). 



Alsine crassifolia (Ehrh.) Britton. Five-finger Rapids 

 (Tarleton). 



