10 BULLETIN 327, U. S. DEPARTMENT OE AGRICULTURE. 



only on moist, decomposed organic, or mineral soils. Natural repro- 

 duction is usually abundant under mature spruce on damp moss over 

 organic soil, and on moss-covered decayed logs and stumps. White 

 spruce reproduces itself poorly on thick leaf -litter of broadleaf trees, 

 because, as in the case of black spruce, the seedlings can not penetrate 

 the tough mass. 



LONGEVITY. 



White spruce is a long-lived tree, reaching an age of from 250 to 

 300 years. 



ENGELMANN SPRUCE. 

 Picea engelmanni Engelmann. 1 



COMMON NAME AND EARLY HISTORY. 



Lumbermen and other woodsmen know this tree mostly as " spruce," 

 while some call it " white spruce," probably because of its general 

 resemblance to the true white spruce (Picea canadensis), with which 

 they may have become acquainted in the East. It is, however, com- 

 monly known to foresters and botanists as Engelmann spruce, a name 

 which it is hoped may be generally adopted both because of its dis- 

 tinctness and the fact also that it commemorates the name of one of 

 the ablest students of western trees. 



It seems probable that Lewis and Clark were the first discoverers 

 of this species, while crossing the Bitter Root Mountains in 1805 on 

 the Lolo Trail. Mention is made in their narrative 2 of a " spruce," 

 which must have been the tree we now know as Picea engelmanni. 

 To Dr. C. C. Parry belongs the credit of having first distinguished 

 this tree, in 1862, from the black spruce (Picea mariana) , for which 

 earlier plant explorers of the Rockies had mistaken it. In that year 

 Dr. Parry found Engelmann spruce on Pikes Peak, Colo., and in 

 1863 is said to have sent seeds of it to the Botanic Garden of Harvard 

 University, where it was probably cultivated for the first time in this 

 country. 3 The first technically established name 1 and description of 



1 Dr. George Engelmann did not name this tree in honor of himself, as might appear 

 from the present form of its technical name. Dr. Parry (Trans. Acad. Sci., St. Louis, II, 

 122, 1863), recognizing that this tree had been erroneously referred by Engelmann to 

 Abies nigra (another distinct species), called it Abies engelmanni, which proved to be a 

 nomen nudum. Later Engelmann (loc. cit., 212) cited Parry's name, A. engelmanni, and 

 in doing this formed a new name, Picea engelmanni, which he credited to Parry. As a 

 matter of fact, Parry did not write Picea engelmanni ; consequently Engelmann was the 

 first publisher of the name Picea engelmanni, but certainly with no intention of naming 

 this tree in honor of himself. 



2 Hist, of Expedition under Command of Lewis and Clark (ed. Cones), II, 590. 

 Whether the discovery was made on the Montana or Idaho side of the Bitter Roots, which 

 the Lolo Trail crosses, appears to be unknown. 



8 According to .James Veitch & Sons (A Manual of Coniferae, p. 69, 1881) Engelmann 

 spruce was introduced into England in 1864, where it appears to grow thriftily. Later it 

 was introduced into Germany and extensively tested for its value in forest plantations. 



