86 MONTANA AGRICULTURAL COLLEGE SCIENCE STUDIES. 



E. dictyospcrma, F. & M. See last above. 



Euphorbia maculata, L. A nearly glabrous form approaching E. 

 serpyllifolia, Pers., but with characteristic spotted leaves. 

 Forsyth, July 24, 1900. 



Euphorbia petaloidea, Engelm. Wibaux, July 9, 1901 ; Tusler, 

 July 7, 1901. 



Euphorbia serpens, HBK. Great Falls, Oct. 24, 1886, R. S. Wil- 

 liams, 160, in part; Miles City, Aug. 16, 1903. 



CALLITRICHACEJE. 



Callitriche Bolanderi, Hegelm. A species close to C. palnstris, L. 

 but larger, with larger, rhombic-ovate leaves and styles longer than 

 the fruit. Apparently not hitherto reported east of the Cascade 

 Mountains, so its occurrence here on the Continental Divide is sur- 

 prising. Bernice, Sept. 7, 1900, 6000 ft. 



ANACARDIACE/E. 



Rhus occidentalis, (Torr.) ; R. glabra occidcntalis, Torrey, Bot. 

 AVilkes Exp. 257; R. glabra, Rydberg, Flora, 479. Differs from 

 R. gtabra, L. in its longer (3-4 dm.), less spreading leaves, usually 

 larger number of leaflets (15-19), which are less acutely serrate and 

 decidedly less glaucus beneath, shorter calyx and linear-oblong 

 anthers. It is also separated in range vrom I\. glabra, not being 

 found east of the Continental Divide, so that with the characters 

 given, it appears to be a good species. Extends from Washington 

 eastward up the Clark's Fork into Montana, but very local in distri- 

 bution in the valley of that stream, as if introduced. It occurs at 

 Ravalli, Jocko and Paradise Valley. 



Rhus Toxicodendron, L. Occurs in the typical form, both 

 shrubby and climbing and should be included in our flora, even if 

 the dwarf form (R.Rydbergii, Small) be regarded as distinct. 

 Kalispell, July 21, 1900. 



AGERACE^E; 



Acer Douglasii, Hook.; A. glabrum Douglasii, Piper. Not in- 

 frequent in the forests west of the Divide, sometimes attaining a 

 diameter of six inches. Distinguished from the common shrub mapie 

 (A. glabrum, Torr.) by being a medium-sized tree, by its larger leaves 

 (8-12 cm. long) and larger fruit. Belton, July 27, 1900. 



