Picea mariana

Picea mariana

The black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb., 1888) is an arboreal species belonging to the Pinaceae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Plantae,
Pinophyta division,
Class Pinopsida,
Pinales Order,
Pinaceae family,
Genus Picea,
Species P. mariana.
The terms are synonyms:
– Abies denticulata Michx.;
– Abies mariana Mill.;
– Abies nigra (Aiton) Poir.;
– Abies nigra (Castigl.) DuRoi;
– Abies nigra Du Roi;
– Abies nigra var. pumila Knight;
– Abies nigra var. pumila Knight ex Godr.;
– Abies nigra var. pumila Knight ex Gordon;
– Peuce rubra Rich.;
– Picea brevifolia Peck;
– Picea brevifolia var. semiprostrata Peck;
– Picea ericoides Bean;
– Picea mariana f. beissneri (Rehder) Rehder;
– Picea mariana f. doumetii (Carrière) O.L.Lipa;
– Picea mariana f. empetroides Vict. & J.Rousseau;
– Picea mariana f. ericoides (Bean) Rehder;
– Picea mariana f. fastigiata Rehder;
– Picea mariana f. grisea Vict.;
– Picea mariana f. mariana;
– Picea mariana f. nana (Beissn.) Rehder;
– Picea mariana f. semiprostrata (Peck) S.F.Blake;
– Picea mariana f. squamea Vict.;
– Picea mariana var. beissneri Rehder;
– Picea mariana var. brevifolia (Peck) Rehd.;
– Picea mariana var. fastigiata (Rehder) Rehder;
– Picea mariana var. mariana (Mill.) Britton, Sterns & Poggenb.;
– Picea mariana var. pendula (Schwer.) Fitschen;
– Picea mariana var. pendula-variegata (Hornibr.) Fitschen;
– Picea mariana var. semiprostrata (Peck) Teeri;
– Picea nigra (Aiton) Link;
– Picea nigra var. brevifolia (Peck) Rehd. ex L.H.Bailey;
– Picea nigra var. brevifolia (Peck) Rehder;
– Picea nigra var. doumetii Carrière;
– Picea nigra var. fastigiata Carrière;
– Picea nigra var. nana Beissn.;
– Picea nigra var. pendula-variegata Hornibr.;
– Picea nigra var. semiprostrata (Peck) Brainerd, L.R.Jones & Eggl.;
– Picea nigra var. virgata Rehder;
– Pinus abies var. mariana (Mill.) Münchh.;
– Pinus canadensis var. nigra Castigl.;
– Pinus canadensis var. nigricans Weston;
– Pinus denticulata (Michx.) Muhl.;
– Pinus mariana (Mill.) Du Roi;
– Pinus mariana (Mill.) DuRoi;
– Pinus marylandica Antoine;
– Pinus nigra Aiton.

Etymology –
The term Picea comes from picea, the Latin name of the wild pine in Virgil and Pliny.
The specific Marian epithet, according to a first interpretation, means of the Virgin Mary.
According to other authors, it refers to Maryland, an area moreover where the species is not endemic, but which in the eighteenth century was believed to be much more extensive by the botanists of the period.

Geographic Distribution and Habitat –
Picea mariana is a conifer native to North America and present in an area that includes: Canada (Ontario, Nova Scotia, Northwest Territories, Saskatchewan, Yukon, Newfoundland, Manitoba, Prince Edward Island, British Columbia, Labrador, Alberta , Québec and New Brunswick) and United States of America (Vermont, Wisconsin, Minnesota, Rhode Island, Alaska, Massachusetts, Maine, New Hampshire, Connecticut, Michigan and Pennsylvania).
Its habitat is mainly that of the muddy areas and marshes, sometimes characterized by the presence of permafrost, from 150 to 800 m of altitude, with the upper limit rising up to 1500-1800 m on the Canadian Rockies; it prefers acidic, peaty soils. The climate of the habitat is cold, with annual rainfall varying between 200 and 1400 mm, with a growing season varying in duration between 25 and 160 days. It is found in pure formations in peat bog or permafrost areas characterized by the presence of Sphagnum. Elsewhere, mixed formations predominate with Picea laxa, Pinus banksiana and Abies balsamea; in elevated areas with Abies lasiocarpa and Pinus contorta and in areas repopulated after fires with Populus tremuloides. In the south-eastern part of the range, the most frequent associations are with Chamaecyparis thyoides, Larix laricina, Populus balsamifera, Acer rubrum, Ulmus americana and Fraxinus nigra.

Description –
The Picea mariana is a conifer with an arboreal habit which can reach 25-30 m in height, even if in its original range it does not by now reach heights of 5-10 m, with variable but generally narrow, conical, or columnar crown, with lower branches that often reach the ground.
The trunk is straight or curved monopodial, with a maximum diameter of 50-60 cm.
The bark is gray or blackish-gray, wrinkled and grooved, with newly exposed parts brown.
First order branches are usually short and slender, drooping. Those of the second order, also short, are dense, especially near the top.
The shoots are short and slender, yellowish or reddish and covered with dense pubescence in the second year, then glabrous starting from the third year; the pulvini are small and slightly pointed.
It has needle-like leaves, glaucous green or dark green in the upper part and green with bluish-white bands in the lower part; they are 0.8-1.2 cm long, linear, with a rhombic section and prickly tips; they have stomata on both sides, with 1-2 lines on the top and 3-4 lines on the bottom.
The vegetative buds are ovoid-conical in shape, 5-6 mm long, slightly resinous; they have triangular, pubescent, purple or purplish-brown pearls, which persist for years.
The male cones are yellowish-brown, carried in the axillary position and often numerous, 1-1.5 cm long.
The female cones are sessile or obliquely pedunculated, ovoid or sub-globular, often in numerous groups and arranged in the upper part of the crown, 2-3,5 cm long and 1,5-2 cm broad, initially reddish or dark purple, then red-brown or deep purple, sometimes persisting for years before falling to the ground. The macrosporophylls are obovate-sub-orbicular in shape, initially rigid then fragile, with a slightly wrinkled, striated and glabrous surface. The bracts are rudimentary, ligulate, 1,2 mm long, totally included. The seeds, of a blackish brown colour, are ovoid-cuneate and 2 mm long; they have the winged part orange-brown, ovate, 5-8 mm long.

Cultivation –
Picea mariana is a conifer which needs abundant humidity at the roots to grow; if it is grown in drier areas it must grow on deeply moist soil.
This plant is tolerant of poor, peaty soils, growing well in moist, cold, shallow soils, but is not very wind tolerant in shallow soils.
From a pedological point of view, it prefers a pH between 4 and 6 and does not like shallow, calcareous soils.
It also does not tolerate shade and atmospheric pollution but resists exposure to wind.
This conifer is one of the most widespread and abundant species in North America, where it is used extensively as a timber tree.
This plant is short lived and slow growing both in the wild and in cultivation.
The new vegetation occurs from the beginning of May to the end of June and rarely exceeds 60 cm even when young and decreases as the tree ages.
It is a conifer that produces many seeds, which usually begins to produce around 10 years of age.
In some mountainous areas, especially on granite or other base-poor soils, growth rate and health have been severely impaired by acid rain-induced aluminum poisoning.
These plants should be planted in open ground when they are quite small, between 30 and 90cm. Larger trees resist transplanting poorly and are unlikely to grow for several years. This also negatively affects root development and wind resistance.
Propagation is by seed. Germination improves with stratification, so it is advisable to sow fresh seeds in the autumn in a cold environment if possible.
Alternatively, the preserved seeds are to be sown as early as possible in the year in an unheated seedbed and in a slightly shaded position.
The seeds should not be allowed to dry out and should be stored in a cool place.
The young seedlings are then placed in individual pots in the greenhouse or in an unheated seedbed for their first winter. They can be transplanted in early summer the following year, or placed in an outdoor nursery for about a year to increase size. They may need protection from spring frosts.
Agamic propagation is also possible. In this case cuttings of semi-mature terminal shoots, 5 – 8 cm long, must be prepared in the period of August to be placed in a semi-shaded seedbed; they will form roots in the spring.
Alternatively, cuttings of mature terminal shoots, 5 – 10 cm long, can be prepared in the period of September / early autumn in an unheated seedbed. They require 12 months to root well.
Another system of agamic propagation is that of using cuttings of soft or semi-mature wood, in the period of early summer in seedbeds; it is a slow but safe system.

Customs and Traditions –
The Picea mariana is of great economic importance for its wood, used in the paper industry especially in the eastern part of the range. The wood is light and hard, very light in colour. Although in decline, it is one of the few North American firs used as Christmas trees, due to the foliage with a compact shape when young.
The aromatic properties of this conifer are exploited in the production of a sort of beer, using the needles, while the shoots and resinous buds are treated and distilled to obtain an aromatic oil used in cosmetics. There is evidence that a drink made from needles, rich in vitamin C, saved the first English inhabitants who settled in Hudson Bay in the eighteenth century from the lethal consequences of scurvy; another historical and ascertained use is the use of roots by the Native Americans to tie together the parts of the canoes made with birch bark, exploiting their elastic properties to keep the seams tight.
Furthermore, there are various cultivars of this species on the market, appreciated in horticulture for its slow and compact growth, and for the color of the foliage with particular bluish reflections.
While the lumber is of little value due to the small size of the trees, it is an important source of wood pulp and primary source in Canada. Fast food chopsticks are often made from this wood.
From the ecological point of view, due to the frequent intervals of fire, in the forests where it grows, most of the populations are of the same age. It commonly grows in pure stands on organic soils and in mixed stands on mineral soils. It tolerates nutrient-poor soils and is commonly found on poorly drained acidic bogs. It is considered a climax species over much of its range; however, some ecologists question whether forests of this conifer really reach their peak because fires usually occur at 50-150 year intervals, while “stable” conditions may not be achieved for several hundred years.
The frequent fire return interval, a natural fire ecology, perpetuates numerous successional communities. Throughout boreal North America, Betula papyrifera and Populus tremuloides are plants that often invade burnt areas of Picea mariana
Even some parasites such as some insects and moths contribute to the mortality of some specimens.
However, due to the vast distribution area and the very numerous presence within it, the Picea mariana is classified as a minimum risk species (least concern in English) in the IUCN Red List.
Finally, please note that this fir is the official tree of Newfoundland and Labrador.

Method of Preparation –
Picea mariana is a tree with multiple uses, both food and medicine, for the use of timber, for ornamental purposes or otherwise.
From the food point of view, the young male catkins are eaten raw or cooked. The immature female cones are eaten cooked. The center portion, once roasted, is sweet and syrupy.
The inner bark is cooked. It is usually harvested in spring and can be dried, ground into a powder and then used as a thickener in soups, etc. or added to cereals when making bread.
However, this use was made above all once as food in times of famine.
The seed could be used as food but due to its low weight it is not very convenient.
With the tips of the young shoots you can prepare a refreshing tea, rich in vitamin C.
A tea is also prepared with the needles and the bark.
A gum is obtained from the bark which is harvested in considerable quantities and used as chewing gum.
The hardened drops, after at least three days, make an excellent chewing gum.
The best gum is obtained from the southern side of the tree.
An oil used commercially for flavoring can be obtained from this plant.
The young twigs are boiled with molasses, sugar, etc. and then fermented to produce “spruce ale”
The beer is ready to drink in a week and is considered a good source of minerals and vitamins.
In the medicinal field, a poultice of the inner bark is applied to the inflammations.
A tea made from the inner bark is a popular remedy for kidney stones, stomach problems and rheumatism.
An infusion of the roots and bark has been used in the treatment of stomach pains, tremors and convulsions.
A resin from the trunk is used as a poultice and ointment on sores to help them heal.
The resin can be mixed with oil and used as a dressing on purulent wounds, bad burns, rashes, scabies and persistent scabs.
The resin can be chewed to aid digestion.
The decoction of gum or leaves has been used in the treatment of respiratory infections and kidney problems.
An infusion of the leaves has been used as a bath or scrub in the treatment of dry skin or sores.
The decoction of the young twigs has been used in the treatment of cough.
The decoction of cones was drunk in the treatment of diarrhea.
The decoction has been used externally as a gargle to treat sore throats.
The cones were chewed to cure mouthache and toothache.
Among other uses, it should be remembered that a yellow-orange dye is obtained from the cones.
Various tribes of native North American Indians made a thread from the long roots of this species and used it to sew the bark of their canoes, to sew baskets, etc.
The pitch obtained from the trunk was used as a sealing material on the hulls of the canoes.
The wood though soft and small is widely used to make boxes, cages, etc. and is prized for its use in the pulp industry to make paper; it is also used as fuel.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/266930424/original.jpeg
– http://www.plantillustrations.org/illustration.php?id_illustration=158558

Attention: The pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not in any way represent a medical prescription; we therefore decline all responsibility for their use for curative, aesthetic or food purposes.