Picea mariana
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Credits
Tom Christian (2025)
Recommended citation
Christian, T. (2025), 'Picea mariana' from the website Trees and Shrubs Online (treesandshrubsonline.
Common Names
- Black Spruce
- Bog Spruce
- Double Spruce
- Gum Spruce
- Lash-Horn
- Swamp Spruce
- Épinette Noire
Synonyms
- Abies mariana Mill.
- Picea brevifolia Peck
- Picea ericoides Bean
- Picea mariana var. beissneri Rehder
- Picea mariana var. fastigiata (Rehder) Rehder
- Picea mariana var. pendula (Schwer.) Fitschen
- Picea mariana var. pendula-variegata (Hornibr.) Fitschen
- Picea mariana var. semiprostrata (Peck) Teeri
- Picea nigra (Castigl.) Link
- Pinus mariana (Mill.) Münchh.
Infraspecifics
Other taxa in genus
- Picea abies
- Picea × albertiana
- Picea alcoquiana
- Picea asperata
- Picea asperata aggregate
- Picea brachytyla
- Picea breweriana
- Picea chihuahuana
- Picea crassifolia
- Picea engelmannii
- Picea farreri
- Picea × fennica
- Picea glauca
- Picea glehnii
- Picea jezoensis
- Picea koraiensis
- Picea koyamae
- Picea likiangensis
- Picea likiangensis aggregate
- Picea linzhiensis
- Picea × lutzii
- Picea × mariorika
- Picea martinezii
- Picea maximowiczii
- Picea mexicana
- Picea meyeri
- Picea morrisonicola
- Picea neoveitchii
- Picea obovata
- Picea omorika
- Picea orientalis
- Picea polita
- Picea pungens
- Picea purpurea
- Picea rubens
- Picea × saaghii
- Picea schrenkiana
- Picea sitchensis
- Picea smithiana
- Picea spinulosa
- Picea wilsonii
Tree 5–10 m tall × 0.2–0.3 m dbh across most of its range, but exceptionally a tree to 20(–30) m × 0.3–0.6 m dbh, and often a stunted low plant to 1.5 m tall. Trunk straight or variably curved in the bole. Bark rough, scaly, flaking, yellowish- or reddish-brown when freshly exposed, soon grey-brown then grey, fissured with age. Crown narrowly conical to spire-like. First order branches short, slender, horizontal to slightly assurgent in the upper crown, horizontal to pendent with age; second order branches short, densely set. Branchlets slender, short, yellowish-brown and densely pubescent at first, but grey and more or less glabrous by the third year, crowded with pulvini. Vegetative buds ovoid-conical, terminal buds on leading shoots 5–6 mm long, lateral buds smaller, not resinous or slightly resinous; bud scales triangular, keeled, acute-cuspidate in terminal buds, pubescent at first, purplish-brown, persisting several years. Leaves radially arranged, swept forwards above shoot, parted beneath especially on shaded shoots, 6–15(–20) × 0.7–0.8 mm, linear, apex abruptly acute, often pungent in the upper crown and on fertile branches where the leaves are strongly rhombic in cross section, but with the apex occasionally obtuse and the leaves somewhat flattened-rhombic in cross section on lower branches and especially shaded shoots; stomata in 1–2 lines on the upper surfaces, 3–4 lines on the lower surfaces; leaves dark green to glaucous green above, green with glaucous-white stomatal bands below. Pollen cones often very crowded, 1–1.5 cm long, yellowish brown. Seed cones terminal or subterminal, often produced in great quantity especially in the upper crown and toward the end of branches growing in good light, ovoid to sub-globose, obliquely pedunculate or sessile, base oblique or curved, 1.5–3.5(–4) cm × 1.5–2(–2.8) cm wide with opened scales; dark blue or violet or purplish when immature, maturing to glossy reddish-brown and finally grey-brown; often persisting for many years. Seed scales obovate-suborbicular, rigid, 0.7–1.2 × 0.6–1 cm at midcone, surfaces usually quite rough, glossy, striated or wrinkled, glabrous; upper margin erose-denticulate, undulate, curved inward. Bracts rudimentary, ligulate, 1–2 mm, entirely included. Seeds ovoid-cuneate, to 2 mm long, blackish-brown; seed wings ovate, 5–8 mm long, orange-brown. (Farjon 2017; Debreczy & Rácz 2011; Taylor 1993).
Distribution Canada Throughout, from the border with Alaska to the Atlantic coast; in western provinces south to e.g. south-central British Columbia and Alberta but not extending south into the United States until its eastward distribution reaches the Great Lakes region on the Canada–Minnesota border. United States Alaska, but absent from the northern states along the Canadian border until the Great Lakes region and the northeast where it extends southward into Connecticut, Maine, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont and Wisconsin.
Habitat In bogs, swamps etc. and on dry peatlands (especially in the south) and in permafrost soils of the taiga ('muskegs') where it co-dominates the northern boreal–sub-arctic forest with Abies balsamea, Larix laricina, Picea glauca and Pinus banksiana; in this habitat broadleaves are mainly represented by Betula papyifera, B. populifolia and Populus tremuloides. At its southern extreme in the NE United States it occurs in mixed conifer forest with Abies balsamea, Chamaecyparis thyoides, Larix laricina and locally Tsuga canadensis, and more diverse broadleaves including Acer rubrum, Fraxinus nigra, Populus balsamifera and Ulmus americana.
USDA Hardiness Zone 2-6
RHS Hardiness Rating H7
Conservation status Least concern (LC)
Taxonomic note As a widely distributed tree in a long-studied region, Picea mariana has collected a long list of synonyms, especially formae names. No infraspecifics are accepted in major works e.g. Farjon (2017) or Taylor (1993); many of the published formae names are now treated as cultivars.
Picea mariana can claim to be one of the most widely distributed and thus ecologically significant trees in northern North America. Along with Larix laricina and P. glauca its distribution stretches from Alaska to the Atlantic seaboard; Abies balsamea and Pinus banksiana also have vast distributions, but not quite so vast, finding their western limit in Alberta and interior British Columbia respectively. P. glauca has the largest distribution of all, extending comfortably south of the Canadian border into Idaho, Montana, Wyoming, South Dakota, and border-adjacent states east of here, while P. mariana and L. laricina are confined north of the border until Minnesota, whence they also extend south into the northeastern United States (Taylor 1993).
Within this group of five species it is the two spruces that are most abundant across this huge area. In the northern parts of its range Picea mariana is common on alluvial and rocky soils, but further south, as the diversity of species it must compete with increases, it tends to be confined to wet and boggy soils, although it is here that it reaches the greatest sizes; P. glauca generally prefers better-drained sites and where both occur together the densely pubescent first and second year shoots of P. mariana separate it from the more or less glabrous P. glauca (Debreczy & Rácz 2011). In the northeastern United States and eastern Canada P. mariana also overlaps with P. rubens; both are pubescent but can generally be separated by the symmetrical, spire-like crown and dark (sometimes glaucous) green foliage with straight needles in P. mariana, cf. a broader, somewhat irregular crown and ‘faintly auburn’ foliage with the inner rows of needles incurved in P. rubens (Warren 1982). When present, old, opened seed cones persisting for some years in the crown of P. mariana are another useful character; in extreme cases cones have been known to persist for twenty to thirty years (Bean 1976).
Picea mariana was an early introduction to European gardens. Bishop Compton is thought to have received material around 1700 and it has probably been in cultivation here ever since, although it is possible that Compton’s original trees had perished by 1751 when P. mariana was absent from a catalogue of the Fulham Palace collection (Elwes & Henry 1906–1913). Its reception in mainland Europe, as in Britain, was probably lukewarm for it is rather slow growing, of no great ornamental merit, and surpassed in every utility by native P. abies. Horticulturally it is probably most valuable in the guise of some of the better cultivars, however, respectable specimens of the type are known both from the maritime climate of Britain and some decidedly continental parts of mainland Europe. This situation mimics the North American experience, whereby the cultivars are more often met with than typical trees in cultivation (Dirr 2009).
An exceptional record from UK cultivation is of a lost tree that used to grow on the Rhinefield Ornamental Drive in England’s New Forest; it was measured at 27 m tall × 56 cm dbh in 1951, putting it on par with the largest records of wild trees, which only reach such dimensions in exceptional circumstances (Mitchell 1972; Debreczy & Rácz 2011). Several closely-grown trees were measured at 21–23 m tall in Lael Forest Garden in the northwest Scottish Highlands in 2013, but the majority of extant UK trees have not (yet) exceeded 20 m (Tree Register 2024). A tree at the Von Gimborn Arboretum, the Netherlands, was 22.5 m × 65 cm in 2011 (Monumental Trees 2024).
'Argenteovariegata'
A selection of typical habit and vigour, with white-variegated leaves. Unfortunately it is prone to scorch when grown in full sun. Raised at the Hesse Nurseries, Germany, before 1891 (Auders & Spicer 2012).
'Aurea'
Synonyms / alternative names
Picea mariana 'Golden'
A medium-sized tree rarely if ever exceeding 10 m tall, relatively narrow in profile especially when young. The new spring growth is fully bright yellow, as the growing season progresses this gradually matures bluish-green but leaving behind a few golden-yellow flecks on the upper leaf surfaces, as though lightly dusted. Rather vigorous, to 2 m tall in ten years, this cultivar was selected in the Hesse Nurseries, Germany, before 1891 (Auders & Spicer 2012). ‘Extremely rare’ in North American cultivation, according to Jacobson (1996).
'Aureovariegata'
The authors of the RHS Encyclopaedia of Conifers (Auders & Spicer 2012) consider this historic cultivar probably lost to cultivation, but this name is still recorded on the database of the Sir Harold Hillier Gardens (Hampshire, UK) in 2025, albeit the last measurement dates from 2002 when a tree, accessioned in 1977, was 10 m tall × 17 cm dbh (19774217*T; Royal Botanic Garden Edinburgh 2025).
'Doumetii'
A slow-growing, broadly-conical plant with silvery-glaucous leaves, eventually a small to medium-sized tree of about 10 m height (Auders & Spicer 2012). Some of the oldest in the UK include two at Bedgebury National Pinetum, Kent, planted adjacent to one another, the first in 1926 and the second in 1935; both were approximately 8 m tall in 2024 (Tree Register 2025; see image below). This cultivar was described (as a botanical variety) from cultivation by Carrière in 1855, from a plant growing at Château de Balaine near Moulins, France, that had been planted about 20 years earlier (Bean 1976).
Picea × moseri Mast.
Described by Masters to cover a hybrid between Picea mariana ‘Doumetii’ and P. jezoensis (presumably subsp. hondoensis) raised by the firm Moser et Fils of Versailles, France (Masters 1901; Plants of the World Online 2025). The foliage is described as generally resembling P. jezoensis but with some intermediate features, notably the leaves somewhat glaucous above (like P. mariana) but also somewhat flattened with silvery stomatal bands beneath (like P. jezoensis) (Auders & Spicer 2012). At the time he reported this hybrid Masters cited correspondence from Moser describing handsome original trees then about 4 m tall, but it is doubtful whether this hybrid is still extant in collections; of the very few images returned by an internet search none correspond to Masters’s description.
Dwarf Cultivars
Here we list a curated selection of cultivars that remain less than 1 m tall and broad ten years from planting. For further introductory remarks on cultivars see the notes at the end of the genus article.
'Austria Broom'
A plant forming a spreading mound with a central depression, bearing short grey-green leaves. Listed by Kenwith Nursery (Devon, UK) in 2003 but its point of origin is unclear (Auders & Spicer 2012).
'Beissneri'
Ultimately a small pyramidal tree with a distinct leading shoot and rich steel-blue leaves, ‘Beissneri’ is a slow-growing plant of very compact growth. Raised in Germany before 1915, it became quite widely grown (Auders & Spicer 2012).
'Beissneri Compacta'
Resembling ‘Beissneri’ but lacking a central leader and more shrub-like in aspect, and slower-growing. Selected in the Hesse Nurseries, Germany before 1954, probably a mutation on ‘Beissneri’ (Auders & Spicer 2012).
'Blue Teardrop'
A dense and compact pyramidal-ovoid bush bearing striking silvery-blue leaves. Raised by Robert Fincham in Washington State in 1990 (Auders & Spicer 2012).
'Edelweiss'Synonyms / alternative names
Picea mariana 'Witch's Broom'
Synonyms / alternative names
Picea mariana 'Witch's Broom'
A diminutive bun suitable for a trough or rock garden, though of rather open habit compared to some selections. To 50 cm tall and broad in ten years. A witches’ broom selected in Austria before 1980 (Auders & Spicer 2012).
'Empetroides'
An entirely procumbent, sparsely-branched mutation in which the leaves are reduced to tiny, thread-like needles 3–6 mm long, this cultivar generally resembles the alpine subshrubs Empetrum in overall aspect. It was discovered on Mt Sterling (Quebec, Canada) around 1930 (Auders & Spicer 2012).
'Ericoides'
A low, spreading plant with a central depression, bearing very short, thin, dark green leaves on wiry shoots. Under optimum conditions plants might reach 30 cm tall with a spread of c. 70 cm after ten years. Cultivated in Britain since about 1864 (Bean 1914) but little is known of its origins; it differs from the much more commonly grown ‘Nana’ in its more spreading habit with a central depression (cf. more or less globose) and in its green leaves (cf. distinctly glaucous-green) (Bean 1976; Auders & Spicer 2012).
'Nana'
A globose dwarf up to 80 cm tall and broad after ten years (though usually less), becoming flat-topped with age and bearing densely set blue-green leaves (Auders & Spicer 2012). This is a very popular cultivar, of unknown origin but recorded by Beissner in 1887, easily distinguished from the much rarer ‘Ericoides’ (see above for details).
'Pygmaea'
Another diminutive bun, but of a more compact and denser habit that, for example, ‘Edelweiss’ and arguably finer for it, though still only likely to appeal to ardent collectors of such clones. To 30 cm tall and broad in ten years. Origin unknown (Auders & Spicer 2012).
'Smoke Juniper'
A globose plant with radially arranged, glaucous-green leaves. To 40 cm tall and broad in ten years. Raised by Jerry Morris – who has selected a great many dwarf conifers – in the United States before 2000 (Auders & Spicer 2012).
'Fastigiata'
A narrow, fastigiate tree with slender branches and short glaucous-grey leaves no more than 1 cm long. Perhaps raised in the Trianon gardens at Versailles, France, from where a plant was sent to Carrière before 1855 (Auders & Spicer 2012). According to Jacobson, trees sold in North America during the 1980s as “Columnar Black Spruce” (Picea nigra ‘Fastigiata’) have nothing whatever to do with this species and represent a fastigiate or otherwise slender sport of P. abies (Jacobson 1996); true P. mariana ‘Fastigiata’ is apparently now very rare.
'Pendula'
A tree with an upright, leading shoot and extremely pendulous first order branches. Raised before 1903 by F. Ganghofer at the Ausber Arboretum, Germany (Auders & Spicer 2012). This is apparently very rare now. The rather similar ‘Pendula Variegata’ is perhaps more frequently encountered, but differs only in the variably yellow-variegated foliage.
'Pendula Variegata'
Very similar to ‘Variegata’, differing only in the yellow-variegated foliage. Commercialised by the UK firm Little & Ballantyne before 1923 (Auders & Spicer 2012). A tree (since lost) at the National Botanic Gardens, Glasnevin, Ireland, was 10 m tall in 2000 (where it was erronously labelled P. mariana ‘Variegata Pendula’) (Tree Register 2025).
'Variegata Spicata'
Tentatively included here on the basis of a single tree at the Sir Harold Hillier Gardens (Hampshire, UK) recorded as being 13.5 m tall × 31 cm dbh in 2010 (accession 19778853*X) (Royal Botanic Garden Edinburgh 2025). No further details are known.
'Virgata'
A sparsely-branched tree, resembling Picea abies ‘Virgata’. This was recorded from American cultivation in 1902, but duplicated cultivar names within the same genus are no longer permitted. This problem may have solved itself as P. mariana ‘Virgata’ may have been lost to cultivation (Auders & Spicer 2012).
'Wellspire'
Common Names
Columnar Black Spruce
Synonyms / alternative names
Picea glauca 'Wellspire'
Picea mariana 'Fast Wells'
A small, narrowly-columnar tree with typical foliage, to 1.5 m tall with a spread of only 50–60 cm in ten years, introduced before 1991 by the Wells Nursery of Mt Vernon, Washington (Auders & Spicer 2012; Jacobson 1996). Initial confusion as to whether this cultivar represented Black Spruce (P. mariana) or White Spruce (P. glauca) or even Norway Spruce (P. abies) (Jacobson 1996) seems to have been resolved (at least if the results, including images, of an internet search are anything to go by – pers. obs. 2025).