Acer cissifolium (Sieb. & Zucc.) K. Koch

It is not clear exactly when the Japanese endemic Acer cissifolium made its way into to western cultivation, nor who was responsible for its introduction. In North American Landscape Trees Jacobson credits von Siebold, saying that it was he who introduced it in 1860; unfortunately Jacobson gives no reference for this information, but he adds that it arrived in North America in 1878 when the Arnold Arboretum received seeds from France (Jacobson 1996). It was certainly collected by Charles Sargent on one of his visits to Japan (Nicholson 1997). Rehder (1927–1940) gives an introduction date of 1875, but both Bean (1976, p.193) and van Gelderen et al. (1994, p.172) say ‘before 1870’. Trees at Westonbirt House (Gloucestershire, UK) were observed by Sargent on a visit in 1907; he ‘considered them to be as large as any he had met with in Japan’ (Jackson 1927, p. 11). These trees are generally thought to have been planted around 1870, which supports the ‘before 1870’ view and possibly adds weight to the von Siebold link.

One of these plants is reputed to have been moved from the grounds of Westonbirt House over to Morley Ride in Westonbirt’s Old Arboretum in the 1920s, where it remained until 2023, having grown into a large, characterful plant exhibiting adventitious roots inside its open middle, though with a tendency to drop limbs (pers. obs.). It was measured at 13 m tall, with a diameter of 69 cm in 2014 (The Tree Register 2025). Two older plants remain in the Westonbirt collection, one on Mitchell Drive in the Old Arboretum measuring 6 m tall and 48 cm diameter in 2024 (The Tree Register 2025), the other planted along Broad Drive in the old Maple Collection in 1878 and as tall, though only 35 cm diameter in 2024 (The Tree Register 2025). Both are female and produce abundant fruit on their old, brittle branches (pers. obs.). Older plants in North America include two individuals at the Arnold Arboretum (AA10649-A and 10649-B) collected by Ernest Wilson in 1918 (Nicholson 1997), recorded as being 45 cm and 48 cm in diameter respectively in 2020 (Arnold Arboretum 2020). A tree of unknown origin growing in Philadelphia was 12.8 m tall with a canopy spread of 16 m in 1980 (Jacobson 1996).

More recently introduced material includes EHOK 139, held in collections on both sides of the Atlantic. A plant at the Arnold Arboretum was propagated from material from Quarryhill Botanical Garden (now Sonoma Botanical Garden), while plants also grow at RBG Kew and the Yorkshire Arboretum in the UK. Plants from BCJMMT 68 represent another collection growing in both North America and Europe. Examples are recorded at Atlanta Botanical Garden, the Arnold Arboretum, New York Botanical Garden and the Polly Hill Arboretum in North America, and at the Royal Botanic Garden Edinburgh, Dawyck Botanic Garden and Arboretum Wespelaar in Europe. Two plants at Wespelaar were raised from seed sent by the Polly Hill Arboretum: one, planted in heavy clay soil and in a frost pocket in 2014, succumbed in June 2021 after an April frost, having flowered heavily the previous year; the second plant, growing in better soil and in a more protected area remains in good health, and colours well in autumn (K. Camelbeke, pers. comm. 2025). There are many young plants establishing well at Benmore Botanic Garden (Argyll, UK) raised from the collections EJE 52 and 165, gathered in 2003 (T. Christian, pers. comm. 2025). Plants from a joint Westonbirt and Wakehurst expedition to Japan in 2011 (WJAP 48) grow in both these UK collections. At Westonbirt plants have so far grown strongly, soon developing their characteristic broad spread. However, like many maples, specimens were significantly damaged by Grey Squirrels in the late spring and early summer of 2024 (pers. obs.).

Besides these known-origin collections, Acer cissifolium of undocumented origin continues to be offered by specialist nurseries. In the UK and much of western Europe it has been available, on and off, ever since its introduction, but it was almost unheard of in the North American nursery trade until the 1960s (Jacobson 1996) and it remains very rare there (Dirr 2009). In cultivation Acer cissifolium typically forms a squat, single or multi-stemmed tree, with a broad spreading crown, aptly described by Bean (1976, p.194) as an ‘elegant species of mushroom-like habit’. In woodland conditions it is more drawn up. It can be quite spectacular in fruit, from early summer onwards, and the foliage colours well in autumn through shades of yellow, orange and red. Dirr (2009) also notes that the ‘slightly dimpled grey bark’ can also be attractive. This maple performs best in a slightly sheltered location on deep, moist, acid soils, and doesn’t enjoy overly dry conditions (Bean 1976; van Gelderen et al. 1994), although it has also been observed growing well on chalk in Cambridgeshire and Hampshire, UK (T. Christian pers. comm. 2025).

Morphologically closest to A. henryi, characters to distinguish the two from one another are provided in the account of that species. The aforementioned surviving plant from BCJMMT 68 at Arboretum Wespelaar has shoots that defy the matt brown description often attributed to A. cissifolium. Being neither green nor brown, they prove that this character can indeed be problematic, and that a combination of characters is best used to distinguish between this species and A. henryi. Both are easily separated from A. negundo by their fewer leaflets: usually three in A. cissifolium and A. henryi, typically five or more in A. negundo.