Acer albopurpurascens Hayata

Endemic to Taiwan, Acer albopurpurascens is the Asian island’s equivalent to A. oblongum, widespread in mainland east Asia, which it has previously been considered a part of. Differences between the two appear to be subtle, though according to Xu et al. (2008), A. albopurpurascens is a smaller tree (15 m vs. 20 m in A. oblongum) with shorter petioles and smaller leaves, their apices acuminate to caudate, rather than acuminate as in A. oblongum.

Infrequent in collections, plants have found their way into western gardens via a range of sources. Material was introduced via the late James Harris in 1978 (Clarke 1988; Harris 2000), founder of Mallet Court Nursery, Somerset, UK, while various introductions have been made more recently by Bleddyn Wynn-Jones and colleagues. The earliest of these was in 2007 from Dasyueshan while collecting with Finlay Colley, under CWJ 12361 from a 10 m tall tree growing at 1850 m asl. Two further introductions made by Bleddyn and Sue Wynn-Jones in collaboration with colleagues from the Taiwan National Museum of Natural Science were made in 2014 under numbers NMWJ 14455 and 14486 (Crûg Farm 2023 onwards). Their advice that the species is “best grown in a sheltered position in a sunny spot out of freezing winds in a relatively well drained soil that does not dry out when establishing” might also be applied to the species’ closest relatives in Sect. Pentaphylla Ser. Trifida. The UK and Irish Champion A. albopurpurascens is a tree of 10 m at Tregrehan, Cornwall, planted in 1989 and measured in 2024 (The Tree Register 2025). The plant at Tregrehan was raised from seed distributed by the Taiwan Forestry Research Initiative, for many years a useful source of Taiwanese material via its Index Seminum, though often not from such high altitude provenances as many western growers would like. The species appears little-tried elsewhere, though is worthy of experimentation, particularly wild origin material gathered from higher elevations.