Northern Prairie Wildlife Research Center
PINE FAMILY (Pinaceae)
IND. STATUS: FACW
FIELD CHARACTERISTICS: An evergreen conifer growing to a height of 10(25) m.; frequently stunted and scrubby. Like those of all spruces, the twigs have woody pegs for the quadrangular (4-sided) needles. The needles are 6-18 mm. long, blue- green and covered with a pale, waxy coating. The twigs and buds are hairy. The cones are 1.5-3.5 cm. long (which is shorter an other spruces), dark purple when young, later turning gray-brown. The cones usually remain on the tree for several years.
ECOLOGICAL NOTES: In Minnesota and Wisconsin, black spruce is typically found in coniferous bogs and scattered in open bogs north of the vegetation tension zone. It often grows with tamarack (Larix laricina). Black spruce is parasitized by dwarf mistletoe (Arceuthobium pusillum) that causes the twigs to form dense clusters called "witches' brooms." Like tamarack, the shallow root systems of black spruce frequently results in "wind throw." Fire hastens opening of the cones. Given a mixed stand of black spruce and tamarack, fires would gradually promote dominance by black spruce while eliminating tamarack, which is very susceptible to fire.
SOURCE: Curtis (1971); Gleason and Cronquist (1991); and Voss (1972).