Page  78 ï~~78 THE MICHIGAN BOTANIST Vol. 39 NOTEWORTHY COLLECTION MICHIGAN PICEA ABIES (Linnaeus) H. Karsten (Pinaceae) Norway Spruce Previous knowledge. Norway spruce is an introduced evergreen tree native from the Alps, Balkans, and Carpathians north to Scandinavia and Russia. In North America it is widely planted as an ornamental or timber tree in the northeastern United States, southeastern Canada, the Rocky Mountain region, and Pacific Coast states (Little 1979). Picea abies was included in the Flora of North America (Taylor 1993) as an established, naturalized species (successfully reproducing and surviving without human intervention). As a former Flora of North America editor, I know that the species was not mapped in that flora because only one specimen representing a naturalized population (from Minnesota, Thieret 1989) was known to the FNA author and Pinaceae editor (Taylor 1993). The species originally was not included in the Michigan Flora (Voss 1973), which included non-native species only if established or naturalized. Two specimens from Alger and Lenawee counties (MICH) support the recent inclusion of Picea abies in the Michigan Flora (as a note added in the third printing, in 1992). Mature trees of this species are frequently seen as ornamentals at homesites, along roadsides, and in plantations. Reproduction in North America is rare in comparison to that of introduced species of Pinus that populate open habitats. The root system of Norway spruce is typically shallow, and seedlings are sensitive to drought and overheating (Kostler 1956), which are increased by direct sun. Successful reproduction depends on small canopy gaps caused by road construction, windfalls, or logging of mature stands (Jonsson & Esseen 1990). Significance. This is the first published report detailing naturalization by Picea abies in the Michigan flora, and contributes to what little is known about the species' naturalization in North America. Seedlings and saplings of Picea abies were found in partial shade, not in open areas or in the deep shade of the parent trees. At both Genesee County sites (details below), offspring ranged from about 15 cm to 2 m tall; in Lapeer County, the largest offspring were larger. Diagnostic characters. Picea abies commonly grows to heights between 100 and 200 feet (30-61 m) (Safford 1974). Cones are the largest (10-18 cm long) of any Picea species in North America. The silhouette of the tree is distinctive with trunk straight and symmetrical, and secondary branchlets drooping straight down from the main branches (Barnes & Wagner 1981). MICHIGAN. GENESEE CO.: West of Grand Blanc, just north of Torrey Road overpass on west side of US highway 23, east-facing road-cut, partially shaded by deciduous tree saplings, T6N R6E Sec. 23 SW%, 7 March 1999, B. D. Parfitt 6049 & C. A. Wade (MICH, UMF); Richfield Park, north side of park road less than 0.3 mile east of Irish Road, T8N R8E Sec. 17 near center of section, under tall white pines with most branches removed and in small partially shaded clearcut in middle of plantation of several native and non-native

Page  79 ï~~2000 THE MICHIGAN BOTANIST 79 species of conifers, at least 40 adults with 5 offspring 3 m tall and more than 100 most less than 0.6 m tall, 10 March 1999, C. A. Wade 1505 (MICH, UMF); Lapeer County, McDowell Road 0.4 miles east of Washburn Road; T8N R9E sec 31 NE of NWY4, along 0.1 mile of south side of road, only a few on sunnier north side, north-facing slope of roadcut, northeast of mature Norway spruces that were probably planted, more than 400 offspring ranging from 10 cm to 3 m tall in natural placement (clearly not planted), B. D. Parfitt 6181 & Charles A. Wade, 27 April 2000 (UMF, MICH); East of Goodrich: west side of Tody Road just north of Fox Lake Road; T6E R9E sec 30 SEX SEA, east-facing side (mostly northeast-facing) of small, mature Norway spruce plantation in deciduous forest; a few spruce individuals about 20-40 m tall, 100 m or more north and south of the plantation along shady road, 28 April 2000, B. D. Parfitt 6183 (UMF, MICH). LITERATURE CITED Barnes, Burton V. & Warren H. Wagner. 1981. Michigan Trees: A Guide to the Trees of Michigan and the Great Lakes Region. University of Michigan Press. Jonsson, Bengt Gunnar & Per-Anders Esseen. 1990. Treefall disturbance maintains high bryophyte diversity in a boreal spruce forest. Journal of Ecology 78: 924-936. Kostler, Josef. 1956. Silviculture. Oliver and Boyd, Edinburgh. Little, E. L., Jr. 1979. Checklist of United States trees (native and naturalized). Agricultural Handbook 541. Washington, DC: U.S. Department of Agriculture, Forest Service. Safford, L. O. 1974. Picea A. Dietr., spruce. In: Schopmeyer, C. S., ed. Seeds of woody plants in the United States. Agricultural Handbook 450. Washington, DC: U.S. Department of Agriculture, Forest Service. Taylor, R. 1993. Picea. In: Flora of North America Editorial Committee, eds. Flora of North America North of Mexico, vol. 2. Oxford University Press, New York. Thieret, J. W. 1989. Picea abies (Pinaceae) naturalized in southeastern Minnesota. Sida 13(4):505. Voss, E. G. 1973. Michigan Flora, part I (Gymnosperms-Monocots). Cranbrook Institute of Science Bulletin 55 and University of Michigan Herbarium, Ann Arbor. -Charles A. Wade Division of Science and Math CS. Mott Community College 1401 East Court Street Flint, MI 48503-2089 -Bruce D. Parfitt Biology Department University of Michigan-Flint Flint, MI 48502-1950