268 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



Callitriche bifida (L.) Morong, Mem. Torr. Bot. Club, 5: 215 [111. 

 Fl. 2: 382]; CaUitrichc ^ahtstris bifida L. Sp. PL 969; C. 

 antnmnalis L. Fl. Suec. Ed. 2: 4 [Man. R. M. 328]. 

 In ponds and slow streams, up to an altitude of 1500 m. 

 Montana: Great Falls, 1891, R. S. WiUianis, 'jj2. 



LIMNANTHACEAE. 



* Floerkia occidentalis. 



Very slender, less than i dm. high, perfectly glabrous, and some- 

 what fleshy; leaves 1-2 cm. long, pinnate with 1-2 pairs of leaf- 

 lets, these oblong or oblanceolate and 5-8 mm. long; pedicels i cm. 

 long or more, longer than the petioles and often equalling the whole 

 leaf in length : sepals ovate, acute, 2—3 mm. long : petals oblanceo- 

 late, about half as long as the sepals ; carpels two, sharply rugose- 

 tuberculate. 



Resembles the eastern F. pr os.cr pi }iacoi dcs , but is a smaller plant, 

 has much shorter leaves with shorter leaflets, comparatively longer 

 pedicels, broader sepals, and sharper-tubercled fruit. In F. proscr- 

 pinacoidcs the pedicels are little if any longer than the petioles and 

 always much shorter than the leaves. In wet places, at an altitude of 

 2000-2500 m. 



Yellowstone Park : Swan Lake, 1885, Tzuccdy, j2j. 



Utah : Wasatch Mountains, 1869, S. IValson, 208. 



Washington: Wilkes Expedition. 



ANACARDIACEAE. 



Rhus trilobata Nutt. ; Torr. & Gray, Fl. N. Am. i : 219 [111. Fl. 2 : 

 387] ; F/iKS aromatica trilobata Gray, Am. Journ. Sci. (II.) 

 33: 408 [Man. R. M. 50; Bot. Cal. i : no] ; RJins Canadensis 

 trilobata Gray; Coult. Cont. U. S. Nat. Herb. 2: 6'$> [Syn. 

 Fl. i': 386]. 



Exposed hill sides, up to an altitude of 2500 m. 

 Montana: Jack Creek, July 14, 1S97, Rydbcrg & Rcssev, 4520; 



Miles City, 1882, Tzceedy, 374: Great Falls, 189^2, R. S. Williams, 



2"/"/; Lewis & Clarke Co., Mrs. Miith; Billings, 1898, Williams & 



Griffith. 



* Rhus Rydbergii Small. 



A single-stemmed shrub, less than a meter high, with grayish, 

 somewhat striate bark ; leaves pinnately 3-foliolate with petioles 

 6-12 dm. long; leaflets 3-10 cm. long, broadly ovate, often some- 



