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Trees & Shrubs of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

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Common Name
Black Spruce (Bog Spruce, Swamp Spruce)

 

Scientific Name
Picea mariana (Mill.) B.S.P.

 

Plant Family
Pine (Pinaceae)

Garden Location
Woodland

 

Prime Season
Late Spring flowering

 

 

 

Black spruce is a native evergreen that forms a small slender tree seldom more than 20 - 30 feet high (but can attain 70 feet in perfect conditions), with a diameter of 4 to 12 inches and with somewhat drooping branches. It is often found with Tamarack, Balsam and White Cedar. It will grow in cold swamps but the growth rate is extremely slow. The lower branches will root in soil by the layering method when snow bends them to the ground.

The bark is dark gray-brown and scaly like the White Spruce.

Young twigs are yellow-brown and tend to have short very fine hair. Buds are gray-brownish and pointed.

Leaves: The needles are 4-sided, stiff, with blunt pointed tips and are the shortest of the spruces, usually less than 3 cm or 1/2 inch long, with fine pores (stomates) in the form of whitish lines on all surfaces, dark bluish-green in color which gives the common name of the plant. They grow thinly over the branches and are attached with a short woody hairy projection (sterigmatas) similar to the White Spruce.

Flowers: This species is monoecious (that is with both male and female flowers). Male flowers are red, turning to light brown at pollination time. The female flowers are found in the crown of the tree, are purple and upright.

Seed: The fruit is an oval shaped cone, 1/2 to 1-1/2 inches long that is purple when young and dark brown at maturity which is about 3 months after pollination. Cones hang downward on a short curved stalk and are usually clustered in the crown of the tree. Cone scales are fan shaped, rigid with the tip usually irregularly toothed. They are the smallest of the spruces and mature in one season but remain partially closed and release the seeds over several seasons. It is estimated that 85% is released within 5 years. Cone production does not start until the tree is about 10 years old.

 

Habitat: Black Spruce has a shallow spreading root system and is very susceptible to wind throw. Lower branches can root by the layering process. It grows in wet organic soils and in the far north in upland sites and is considered a climax species. Seedlings are shade tolerant but full sun is needed for regular growth. The tree is a host for the parasitic mistletoe, Arceuthobium pusillum, which causes a witch's broom growth.

Names: The genus name Picea is the classical Latin name for the 'Pine' but Linnaeus assigned it to Spruces. The species, mariana, is used in two circumstances - one for plants with mottled leaves and one, meaning 'of Maryland', for plants where the type was named - and that is the case with P. mariana. The author names for the plant classification are twofold: First ‘(Mill.)’ refers to Philip Miller, Scottish botanist (1691-1771) who was chief gardener at the Chelsea Physic Garden and wrote "The Gardener's Dictionary". His work was amended by B.S.P. which refers to Britton, Sterns & Poggenb. Details on who these people were is at the page bottom.

Comparisons: The White Spruce, P. glauca, is also widely distributed but does not occupy moist sites. Flowers and cones are similar but the needles of P. glauca are longer - about 3/4 inches - lighter blue-green in color, thicker on the branches and the lower branches do not take root by layering and twigs do not have hair. P. glauca is also a larger tree, becoming 1 to 2 feet in diameter.

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

Small Tree Drawing

Above: Black Spruce is a slow growing slender tree, usually short, with stiff 4-sided needles, and somewhat drooping branches near the ground. Drawing by Britton & Brown, courtesy USDA-NRCS Plants Database.

Below: Needles are short with pegged bases with fine whitish pore lines. New twigs have fine brownish hair. The male flowers are in a hanging strobilus at the end of twigs. Twig photo ©Gary Fewless, University of Wisconsin; Male flower photo ©Virginia Tech Dept of Forestry.

Twig Needles Male Flower

Below: The developing cones are near the top of the tree and hang downward. Scales are fan shaped. Cone photo ©Matthew Wagner, University of Wisconsin. Older bark is gray-brown and scaly.

Cones Old Bark Leader

Notes:

Eloise Butler first noted Black Spruce in her Garden Log on April 14, 1910 when she reported replanting two plants that someone uprooted. This reads like they were uprooted in the Garden, but there is no mention of this plant in her log prior to this. She does report planting the species in 1911, '12, '17 and '20. The plant is on Martha Crone's 1951 Garden census and subsequent census reports.

Black Spruce is a species of the northern forests, being found in all of Canada and in the U.S. only from Minnesota eastward to the coast, no farther south than northern Illinois, Pennsylvania and New Jersey. Within Minnesota it is native principally to the NE Quadrant south as far as Anoka County. It is not native to Hennepin or other metro counties. The Black Spruce and White Spruce, P. glauca, are the only species of Picea native to Minnesota.

Common uses: The wood is light and soft, used extensively for paper pulp.

Medicinal history: The life-saving stories about the anti-scorbic properties of certain trees that provided cures for the dreaded scurvy among early mariners, began with the introduction of Europeans to the Northern White Cedar, Thuja occidentalis, in 1536. In the 1750s the not-yet famous James Cook spent time as a ship's master on the northern coast of North America and became acquainted with the medicinally qualities of the Black Spruce. Cook would establish a reputation as a ship's captain who understood the effects of scurvy and what to do about it - long before the Royal Navy adopted the proper procedures. Cook knew that freshly made 'spruce beer' was a remedy and preventative for scurvy and whenever he could gather fresh young shoots, he had a brew made. Water, molasses and yeast were needed for the process. (Gurney provides a recipe.) It apparently was better tasting than the tea made from Northern White Cedar as Spruce Beer was still made late into the 19th century. (Ref. #6 and Alan Gurney, Below the Convergence.)

Classification authorship: The botanical author citation "B.S.P." refers to three botanists who collaborated on the classification of numerous species, particular those in and near New York as all three were members of the Torrey Botanical Club.

'B' refers to Nathaniel Lord Britton (1859-1934) American botanist and taxonomist, co-founder of the New York Botanical Garden, signatory of the American Code of Botanical Nomenclature and co-author with Addison Brown of An Illustrated Flora of the Northern United States, Canada, and the British Possessions in 1896.

'P' refers to Justus Ferdinand Poggenburg I (1840-1893), botanist.

'S' refers to Emerson Ellick Sterns (1846-1926) American botanist, Co-founder of the New York Botanical Garden.

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

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