10 BULLETIN" 327, U. S. DEPARTMENT OF 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 EAELY 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 Eoot 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. Coues), 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. 
3 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. 
