Sciadopitys verticillata (Thunb.) Sieb. & Zucc.

Sciadopitys verticillata is one of the most fascinating of all conifers. A so-called living fossil, it sits alone, one species in one genus in its own family, with no close living relatives, but with a fossil record that can track its ancestors back some 230 million years (Farjon 2008). The peculiar arrangement of its leaves is unique among conifers, as is the production of a latex-like, non-resinous sap (Yates et al. 2019; and see genus article). Revered in its native Japan where its timber has been highly prized, it is slow growing even in the wild where, as in gardens, it forms dense, slender, beautiful spires of lustrous dark green foliage. In Japanese culture Sciadopitys is one of the five sacred trees of Kiso, the others being Chamaecyparis obtusa, C. pisifera, Thuja standishii and Thujopsis dolabrata. In ancient feudal Japan these trees were reserved exclusively for imperial use, and any unsanctioned felling was considered a capital offence (Wilson 1928).

Perhaps it was this combination of botanical and cultural significance that persuaded W.J. Bean to choose Sciadopitys to illustrate the spine of the first edition of his seminal Trees and Shrubs Hardy in the British Isles (Bean 1914). Its significance in Japanese culture is maintained to the present day: Sciadopitys was chosen for the mon (Imperial crest) of Prince Hisahito of Akishino (b. 2006), currently third in line to the Chrysanthemum Throne (American Conifer Society 2022).

Despite the reverence this tree has long enjoyed in Japan, it was not always a particularly popular garden specimen there. It has been more widely planted in recent decades (BJ pers. obs.) but in 1892 Sargent noted that it was only commonly planted as an ornamental in the area around Nakatsugawa and in the precincts of temples (the Japanese name Koyamaki refers to the richly templed Mount Koya, one of its sites of greatest natural abundance) (Sargent 1894). The durability of Umbrella Pine’s timber has made it an attractive subject in forestry, and both natural and planted forests have been managed for timber. The fragrant white wood is useful in construction and furniture making; it resists water well and has been used to build boats and bathtubs, as well as in casks and panelling (Eckenwalder 2009). However, past logging and subsequent conversion of forests to planted monocultures has fragmented native populations in many regions, with few now numbering more than about 100 individuals, contributing to the tree’s IUCN Red List Status of Near Threatened (Thomas 2019).

As a wild tree Sciadopitys is distributed from central Honshu south to Shikoku and Kyushu, predominantly in the Chubu, Kinki, and Shikoku districts, with isolated populations scattered throughout Tohoku, Chugoku, and Kyushu districts (Thomas 2019). It occurs mainly in rocky, cool and moist ravines and valleys in mountainous areas over an altitudinal range of 200–1700 m asl in mixed conifer-angiosperm forests with a broad range of associates (Debreczy & Rácz 2011). In dense forest only shade tolerant plants like ferns, mosses and liverworts grow on the forest floor, but in some localities shade tolerant shrubs can thrive. in 1904 Henry Elwes saw Sciadopitys to its ‘best advantage’ in the Atera Valley ‘on a steep rocky hill […] mixed with Thujopsis, the undergrowth being very dense, and composed of Rhododendron, with Shortia uniflora spreading over the ground in great sheets’ (Elwes & Henry 1906–1913).

Both authors of this account have had the privilege of seeing Sciadopitys in the wild and introducing seed collections to botanic gardens in the UK for ex-situ conservation. Tom Christian recalls meeting it for the first time as a wild plant on the Daijagura Cliff in Honshu’s Odaigahara Mountains, in the autumn of 2013: growing out of nothing more than cracks in the bare rock, stunted Sciadopitys sprang from the ridge top and, at no more than about 10 m tall, stood sentinel over a sub-canopy of Quercus crispula, Trochodendron aralioides, Acer shirasawanum, Sorbus commixta, Rhododendron degronianum, R. quinquefolium, and an Enkianthus species whose identity nobody could be sure of. Thick mists came in waves, blocking out the autumn sun and temporarily vanishing distant views, turning the ridgetop where our team was working into an island on a sea of vapour. Beyond the precipitous cliffs the earth fell away into this misty abyss, but in the far distance we could see other islands, isolated peaks and ridges floating like we were, populated by the dark, spire-like crowns of Umbrella Pines.

As at Daijagura, Sciadopitys can occur in scattered groves, or at other times as isolated trees in mixed forest, or in more or less pure stands depending on the local species diversity and on the successional stage of the forest. The most abundant regeneration always seems to occur in deep shade (Elwes & Henry 1906–1913) of which this conifer remains tolerant throughout its life, and even in a nursery as far north as that of the Royal Botanic Garden Edinburgh some shade netting was necessary to successfully bring young seedlings through the summer months, and young trees establish best in situations with at least some shade (TC pers. obs.).

Described by Thunberg in 1784, the early history of Sciadopitys in western gardens is curiously entwined with that of another Japanese conifer, Thujopsis dolabrata. The first attempt to introduce both species to western gardens was probably made in 1853, when Thomas Lobb dispatched a single living plant of each from the Botanic Garden at Buitenzorg (modern Bogor, Java) to the Veitch Nurseries in Exeter, but both conifers perished soon after landing in England (Shephard 2012). The first successful introductions would take place in 1861, after James Gould Veitch and Robert Fortune separately collected seeds in Japan the previous autumn, Veitch’s naturally going to his family firm and Fortune’s to the Standish nurseries at Ascot, enabling these rival firms to offer these two, new, exotic conifers at more or less the same time (Elwes & Henry 1906–1913). The first introduction to America followed only months later, when Dr G.R. Hall introduced material in 1862 (Wilson 1928). Sciadopitys was an instant hit, ‘fast becoming as sought after as William Lobb’s ‘Wellingtonia’ [Sequoiadendron giganteum]’ (Shephard 2012).

While Sciadopitys was extensively planted and found to be superbly cold hardy, and quite at home in continental and maritime climates alike, it soon revealed itself to be particularly slow-growing and otherwise rather exacting in its requirements. In Veitch’s second Manual of the Coniferae Adolphus Kent observed, somewhat tartly, that ‘Complaints have arisen in many places that it will not grow, whence it is evident that its requirements have not been met’ (Kent 1900). It is impossible even to estimate the number of nurserymen who have paraphrased this sentiment about countless plants since Kent penned it in connection to Umbrella Pine. Henry Elwes adopted a more empathetic tone, prescribing ‘shade, perfect drainage, and a rich forest soil’ adding that seedlings ‘seem to require a very light, sandy peat when young, and refuse to grow in soil which contains lime, or where moisture is deficient during the summer’ (Elwes & Henry 1906–1913). Indeed, Sciadopitys can be a fickle subject in the nursery and prone to chlorosis, especially in modern peat-free mixes, but planted out in garden soil plants usually recover well; a stubbornly chlorotic seedling was planted out at Benmore Botanic Garden in Argyll when it was little more than 10 cm tall; within a year it was restored to full health and is now a thriving young tree (TC pers. obs.). In cold-climate areas some winter coloration of the foliage, typically bronzy hues, is quite common.

Mature specimens in warmer parts of Europe, such as around the Italian Lakes, show that so long as soils do not dry out Sciadopitys is quite welcoming of summer warmth (TC pers. obs. 2021). Indeed, the four largest girths on cultivated trees recorded by the website monumentaltrees.com are in northwest Spain and northern Italy, ranging from c. 3 m circumference at the Villa Taranto on Lake Maggiore, to 3.85 m in Tui, Galicia, just inside Spain’s northern border with Portugal (monumentaltrees.com 2022). Both are significantly larger than the largest known in Britain, a tree 2.5 m in circumference at Scorrier House, Cornwall (Tree Register 2022). Britain does rather better when it comes to height, with the tallest on record to 24.2 m in 2019 at Benenden School, Kent, and other notable trees including: 23 m in 2016 at Bodnant, Conwy; 20.2 m in 2022 at Sheffield Park, Sussex; 19.2 m at Mount Stuart, Argyll, and 19 m at Mount Usher, Wicklow, Ireland (Tree Register 2022). There are trees to 13.6 m in Germany and 16 m in the Netherlands (monumentaltrees.com 2022), but the tallest cultivated examples of all have been recorded in North America: to 27.4 m in the early 1970s at Amherst, Massachusetts, dating to an 1876 introduction by Dr. William S. Clark (Weber 1973).

A curious feature of some individuals of Sciadopitys is the production of abnormal cones, in which leaves project beyond the apex of the cone, which has interested plant morphologists since soon after it became known in Europe (Masters 1869). It is caused by the reversion of the determinate reproductive cone axis to indeterminate vegetative growth; similar examples are also known in extant Pinaceae (Picea, Abies), Cephalotaxaceae (Cephalotaxus), and Cupressaceae (Cunninghammia, Cryptomeria, Sequoia) (Bateman, Hilton & Rudall 2011).

For many years there were very few known cultivars of Sciadopitys. Sargent saw a pendulous tree in a park in Tokyo (Sargent 1894) and Bean knew of a similar plant in a park in London (Bean 1981); golden and variegated forms were introduced to the west from Japan almost as soon as the species itself in the 19th century, but most of the cultivars listed below have been selected from western gardens since the 1960s (Auders & Spicer 2012). It is a moot point whether any can rival the beauty of the natural form of the species, but gardeners do now have a considerable range of variants at their disposal, including, in isolation or combination, yellow- or cream-leaved, variegated, dwarf, slow-growing, pendulous and tightly columnar to almost fastigiate forms. Unfortunately, Sciadopitys is a genus in which yellow-leaved forms really do look quite sickly and only very few such selections can be labelled passably attractive; of far greater garden worthiness are the relatively few dwarf and particularly slow-growing cultivars, especially those of narrow habit, which make striking subjects for more intimate garden spaces.