CONTRIBUTIONS TO WESTERN BOTANY. 627 



Yellowstone Park, Tweedy; Mt. Adams, Washington, 

 Howell; Yellowstone Park, Rose. 



This grows in volcanic gravel above timber line, form- 

 ing loose mats 7-15' in diameter, and grows along with 

 Stellaria longipes and Phlox Doiiglasii. 



The Y2ir\ety gracilis Robinson, occupying the same zone 

 as this variety, has slender-tipped, pungent leaves and 

 bracts, and subulate-lanceolate sepals, with a very promi- 

 nent midvein, which runs off into a sharp and rather 

 long awn, the sepals being i-iy^" long. This is Bolander's 

 No. 4976. Coville and Funston's No. 1546 has little 

 broader sepals and condensed habit, but the sepals, leaves 

 and bracts are all pungent. Palmer's No. 195 seems to 

 be about the same. All these are high altitude forms, 

 growing in a very cold alpine zone, while the true Niit- 

 tal Hi grows in low, warm and arid altitudes, in a wholly 

 different zone. 



Arenaria Kingii (Wats. King's Rep. 39, t. 6). 



Stellaria Kingii Wats. 1. c. 



No. 5515. Manti, Utah, June 27, 6000° alt., in gravel, 

 on dry slopes. 



Having at last collected this species, it is manifest that 

 it is a true Arenaria instead of a Stellaria, in spite of the 

 bifid petals ; in fact, it cannot be distinguished from the 

 allied species of Arenaria, except by the petals. There 

 is no Stellaria with which it has anything in common. It 

 grows on gravely hills. 



Acer glabrum var. tripartitum (Nutt. T. & G., Fl. i, 

 247). 

 This would seem worthy of recognition as a variety. 

 It is the usual Rocky Mountain form, with leaves i-ji^' 

 long, with three leaflets, or at least nearly parted, short 

 racemes, 1-2' long; wing of fruit 6" long, and peduncles 



