Picea maximowiczii Regel ex Mast.

Picea maximowiczii is one of four spruces endemic to Japan (the others being P. alcoquiana, P. koyamae and P. polita). Along with P. koyamae it has only a narrow, fragmented distribution in the Japanese Alps on the Pacific side of central Honshu, where it occurs as a stunted tree in poorly drained mountain soils, or scattered in forests with P. alcoquiana, P. koyamae and various broadleaves.

Tschonoski discovered it there in 1864 whilst collecting for Maximowicz (that he did not discover Picea koyamae at the same time hints both at the precise locality and how challenging this area’s topography was to early botanists). His gatherings included herbarium specimens and seed, both of which arrived in European institutions the following year courtesy of Eduard von Regel, Director of the Imperial Garden in St Petersburg. The species would be described from this material a short while later (Farjon 2017). It would be nearly fifty years before anybody re-found P. maximowiczii in the wild; the long wait, and the fact this species was not cultivated in Japanese gardens accessible to westerners, led some to suspect a mix up and that P. maximowiczii might not be a Japanese native at all (Wilson 1916). The matter was settled by Mitsua Koyama’s rediscovery of this species in 1911, the same year he discovered P. koyamae (Bean 1976). Koyama would later lead E.H. Wilson to visit both these narrow endemics in habitat, with Wilson later attesting to their remote, mountainous abodes to which access is ‘exceedingly difficult’ (Wilson 1916).

According to Bean, Kew’s share of Tschonoski’s seed had produced only ‘a small, stunted bush’, but the same material was growing better, albeit slowly, in collections in mainland Europe (Bean 1976). Indeed, there was some doubt in the early 20th century whether Picea maximowiczii had been lost from cultivation in Britain, particularly because no surviving trees dislpayed the same radial leaf arrangement that had characterised them in youth (Bean 1976). This was thought to be a feature of juvenile material only, but mature specimens at Gothenburg Botanic Garden, Sweden, exhibit this too (pers. obs.). This leaf arrangement explains the Japanese name that translates as ‘daughter of the Tigertail Spruce’ (P. polita, which has radially arranged leaves throughout its life) (Debreczy & Rácz 2011), although Wilson observed adult trees to strongly resemble P. polita, too (Wilson 1916).

Wilson would also observe that, in typical habitat, this is not an especially large-growing spruce. The largest he saw in native forest were about 20 m tall, but trees growing in temple gardens within its general area of distribution were larger, to 25 m and 64 cm dbh according to his own observations (Wilson 1916). This chimes with observations made by the EIKJE collecting team in 2013, which included the present author: trees in native forest at Senmai-Iwa were 10–15 m tall, while those cultivated as a windbreak on a farm near Yamanashi were c. 25 m tall and perhaps averaged 35 cm dbh (EIKJE collection notes; pers. obs. 2013). The trees forming the windbreak had started out as saplings, removed from native forest in the nearby Futatsu-yama population around 1923; this provenance, and their isolation from other sub-populations, made them suitable for sampling under EIKJE 244, 245, 246 and 248 (Royal Botanic Garden Edinburgh 2024). Seed was shared between RBG Edinburgh, Kew and Bedgebury in the UK, and although nowhere did it germinate in large numbers, those that did grew slowly but steadily and have now been planted out in a range of locations, including Edinburgh, Benmore and Dawyck Botanic Gardens in Scotland, and Kew, Bedgebury and Westonbirt in England, and a handful of other locations. In the Scottish collections at least, young trees have the radial leaf arrangement reported in early literature and quite different from mature specimens (pers. obs. 2024).

Mature trees are few, although examples may be growing under various other names. At Bicton Park Botanical Gardens (Devon, UK) the present author found two trees labelled Picea engelmannii in 2018, but undoubtedly P. maximowiczii. Two very handsome trees grow just below the chapel at Dawyck in the Scottish borders, but these are now beginning to dieback in response to attack by the Great Spruce-bark Beetle (Dendroctonus micans) (pers. obs. 2024). The largest on record in the UK grow at Westonbirt, Gloucestershire, 27.3 m × 77 cm dbh in 2024, and at Thorp Perrow, North Yorkshire, 27 m × 73 cm in 2021; indeed, of the top ten on the Tree Regiser of Britain and Ireland, five grow at Westonbirt, between 22.5 and 27.3 m in 2024 (Tree Register 2024). A young tree at Kew, donated by Atushi Kuyama in 1981 and about 6 m in April 2005 (Grimshaw & Bayton 2009) was 11.7 m × 31 cm in 2022 (Tree Register 2024).

Picea maximowiczii appears to be very rare in North America. It is not reported from the Arnold Arboretum, Washington Park Arboretum, nor UBC Botanic Garden in Vancouver (Arnold Arboretum 2024; Hoyt Arboretum 2024; University of British Columbia Botanical Garden 2024), while the Morris has a single plant (Morris Arboretum 2024). Jacobson cites three notable specimens, 15 m × 46 cm dbh (with a canopy spread of 12 m) in Philadelphia in 1980; 12 m × 25 cm in Lisle, Illinois in 1986 from a 1953 planting; and 6.8 m × 19 cm (with a canopy spread of 6.5 m) in Seattle in 1994 from a 1950 planting (Jacobson 1996). In mainland Europe this spruce is similarly uncommon. Gothenburg Botanic Garden, Sweden, bucks this trend and has several specimens accessioned in 1959, none of them more than about 15 m tall (pers. obs. 2019).

Picea maximowiczii is actually quite a distinctive spruce, but it is one of those curious plants whose distinctiveness is hard to put into words. It is most likely to be confused with P. orientalis, sharing a very dark green leaf colour, pale shoot colour, dense crown architecture, and general appearance of the bark, but P. maximowiczii differs in its (slightly) longer leaves, radially arranged in some trees and otherwise more widely spreading from the shoot, while its seed cones are broader in proportion to their length, and the bark is paler. P. maximowiczii also bears some resemblance to P. abies and P. wilsonii, but has shorter leaves of a darker green, smaller seed cones, and, at least compared with P. abies, a much lighter coloured shoot. (pers. obs.).