Acer nigrum Michaux

Closely allied to Acer saccharum within the sugar maple complex, A. nigrum is valued next to that species for syrup production, and the timber of the two is considered indistinguishable; both are referred to as hard maple in the trade (Grimm 2002). In terms of distinguishing the two in the field, A. nigrum is often distinguished from A. saccharum by its drooping leaves. While this character can be useful, it is not always reliable, and should only be used in combination with other characters. The bark of A. nigrum is more deeply fissured and darker, to which the Black Maple moniker refers. Shoots of A. nigrum are generally stouter than those of A. Saccharum, but a clear distinction between the two, at least early in the season, are the stipulate leaves of A. nigrum. Indeed, this character separates A. nigrum from all other maples. Sargent (in Bean 1976) notes the orange-coloured branchlets as a useful character for distinguishing the A. nigrum from A. saccharum all year round, though this character is also somewhat variable. Reported hybrids naturally have characters intermediate between the two species.

Horticulturally, Acer nigrum attains equal stature to A. saccharum and is considered the more heat and drought tolerant of the two (Kurz 2003; Dirr & Warren 2019). It is shade tolerant, slower growing and also long-lived (Kurz 2003), and though it tends to lack reds in its autumn colour, is consistent none the less. It is however more susceptible to leaf tatter than the best A. saccharum selections, and is less used than that species, as reflected in its fewer cultivars.

The tallest example recorded in the UK attained 22 m at Alexandra Park, Hastings, though it died in 1995 (The Tree Register 2022). The current champion is a tree at the Sir Harold Hillier Gardens which measured at 17.4 m in 2022, though individuals at the Royal Botanic Garden Edinburgh and in the garden of the Hare and Hounds, Westonbirt, were both 17 m in 2014 (The Tree Register 2022). The species has grown taller elsewhere in Europe, with a male tree at Rogów, Poland planted in 1958, standing 24 m tall with a diameter of 64 cm in 2023 (P. Banaszczak pers. comm. 2023).