724 GEOLOGY OF THE YELLOWSTONE NATIONAL PARK. 



LaURU8 MONTANA U. Sp. 



PL XCV, flg. 2. 



Leaves large, evideiitlv ciiriaccinis, elliptical-lanceolate, narrowed grad- 

 nally (?) to the petiole and ( ?) npward to an acuminate apex (?), slightly 

 nne([ual-sided in the upper jiart; margin entire; midril) thin, straight; second- 

 aries 5 or 6 jtairs, alternate, the lower at a very acute angle, upper ones 

 slightly less so, all, liut especialh' the lower ones, with numerous branches 

 on the outside, which join and form broad loops just inside the margin; 

 nervilles strong, percurrent, apprcjximately at i-ight angles to the secondaries; 

 vdtimate nervation not j)reserved. 



The leaf Ijy which this tine s[)ecies is represented unfortunately lacks 

 both base ami apex, but is otherwise well preserved. It is 10 cm. long as 

 now preserved, and was, when entire, probably at least 14 cm. in length. 

 The width is 5.3 cm. As stated, it is a little (3 nun.) wider on one side of 

 the midril) than the other, making it slightly une(|ual-sided. The nerva- 

 tion is peculiar, consisting of aliout 5 pairs of secondaries, of which the 

 lower, on the narrower side of the leaf, l)egins well toward the base and 

 passes up to the middle of the Ijlade, with numerous liranches on the out- 

 side at right angles to the midrib The lower secondary on the broad 

 side (tf the leaf is very thin and short, and anastomoses with a branch 

 from the lower portion of the second secondary. This latter is strong, and 

 passes above the middle of tlie leaf, and has only 4 or 5 branches on the 

 outside, all being at an acute angle with the midrib. The other second- 

 aries have 1 or more l)ranclies on i)utside, and also a number of strong 

 nervilles. 



This species appears to be related to some of the forms figured by 

 Lesquereux as Laurus graudls,^ from California, and may possibl}- be an 

 anomalous form of this species. It is larger, more rounded, slightly uneqiial- 

 sided, and has (piite different nervation. It also resembles L. californica Lx.,^ 

 from the same place. 



Habitat: Yellowstone River, one-half mile l)elow mouth of Elk Creek, 

 base of bluff; collected by F. H. Ivnowlton, August, 1888. 



'Cret. and Tert. Fl., I'l. LVIII, fig-. 3. 

 ^Op. fit., PI. LVIII, tig. 8. 



