NOTES ON NORTH AMERICAN TREES. IV 



C. S. Sargent 



PiCEA GLAUCA (Mocnch) Voss, Mitt. Deutsch. Dendr. Ges. 

 16:93. 1907. — Although Abies canadensis Miller is the oldest name 

 for the white spruce, Picea glauca, according to the rules of the 

 Vienna Congress, must be adopted for this tree, for there is a 

 Picea canadensis, which is a valid name for the hemlock spruce under 

 the genus Picea. The Rocky Mountain variety then becomes 



Picea glauca var. albertiana, n. comb. — Picea canadensis var. 

 albertiana Rehder, Mitt. Deutsch. Dendr. Ges. 24:213. 1916. 



JuNiPERUS UTAHENSis var. mcgalocarpa, n. var. — Juniperus 

 megalocarpa Sudworth, Forestry and Irrigation 13:307. figs, i and 

 2. 1907; Wooton and Standley, Contrib. U.S. Nat. Herb. 19:37. 

 1915. — Sahina megalocarpa Cockerell, Muhlenbergia 3:143. 1907. 

 — Differing from the type in its larger fruit sometimes i . 7 cm. in 

 diameter, and in its habit of sometimes forming a single erect stem. 



A tree 10-14 n^- high, with a straight trunk occasionally i-i .2 m. in 

 diameter. 



Valley of the San Francisco River near Alma, southwestern New Mexico, 

 W. R. Mattoon, September 1906, Alfred Rehder, August 13 and 14, 1914 (nos. 

 285, 285b, 289); Arizona: rim of the Grand Canyon, C. 5. Sargent, Septem- 

 ber 9, 1904; Angel, near Flagstaff, Percival Lowell, September 4, 1910. 



Mr. Rehder visited the type station of this tree in New Mexico in August 

 1914 and obtained a large amount of material which shows that it must be 

 considered a variety of /. utahensis, for he found trees with fruit intermediate 

 in size between that of the typical /. utahensis (6-7 mm. in diameter) and the 

 largest fruits of /. megalocarpa, that the trees with single stems did not always 

 produce large fruit, and that the large-fruited trees sometimes had the charac- 

 teristic habit of /. utahensis. Like that of /. utahensis, the fruit of the variety 

 ripens at the end of the second season. A specimen of /. utahensis in the 

 herbarium of the Arboretum collected by E. Bethel at Radium, Colorado, in 

 November 1908 at an elevation of 2300 m., has fruit 1.3 cm. in diameter and 

 should perhaps be referred to the variety. 



PoPULUs TREMULOiDES var. vancouveriana, n. var. — Populus 

 vancouveriana Trelease apud Tidestrom in Piper and Beattie, Fl. 

 Botanical Gazette, vol. 67] [208 



