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Dan Crowley (2020)
Crowley, D. (2020), 'Acer granatense' from the website Trees and Shrubs Online (treesandshrubsonline.
A deciduous shrub or tree to 12 m in the wild. Bark brown. Branchlets glabrous. Buds ovoid, acute tipped, with many pairs of imbricate scales, brown. Leaves subcoriaceous to coriaceous, broadly pentagonal in outline, base cordate, (3–) 5-lobed, (1.5–) 2.5–8 (–10) × (1.5–) 2.5–9 (–11) cm, lobes ovate, to half the length of the blade, lateral lobes spreading, basal lobes smaller, apex acute, margins irregularly serrate, upper surface mid to dark green, lower surface paler, usually pubescent along veins and in axils; petiole 4–11 cm long, green or red, glabrous or pubescent, faintly grooved and broadening towards the base; autumn colours yellow. Inflorescence terminal, umbellate, pedicel usually pubescent, pendulous. Flowers yellow, 5-merous. Samaras to 2–3.5 cm long, wings spreading variously; nutlets rounded. Flowering from March to April, before or with the leaves, fruiting from September to October. (Güemes Heras & Sánchez Gómez 2015).
Distribution Morocco Spain Mainland and Mallorca.
Habitat North facing slopes and rocky areas between 190 and 2000 m asl.
USDA Hardiness Zone 6-7
RHS Hardiness Rating H5
Conservation status Least concern (LC)
Taxonomic note This species was treated as Acer opalus subsp. hispanicum by van Gelderen et al. (1994), though it appears distinct from A. opalus and likely closer to A. hyrcanum than to A. opalus. While the oldest name listed at species rank in its synonomy in van Gelderen et al. (1994) is A. hispanicum Pourret, this is in fact referable to A. opalus rather than this taxon, leaving A. granatense as the first name available. The combination of A. hyrcanum var. granatense, sometimes seen on labels, appears not to be validly published. It is quite distinct from A. opalus in its smaller, irregularly serrate leaves, which in A. opalus are remotely serrate to entire.
Despite being native to Europe, Acer granatense appears to be only a recent introduction to cultivation, though it is now represented from Spanish and Moroccan origins. McB 2568 was collected in Cazorla, Spain, in 1991 and two examples of it grow at Westonbirt Arboretum, Gloucestershire, where they have a slightly untidy, rounded form and offer little in the way of autumn colour. Similarly from Cazorla are plants at Ness which have suffered from squirrel damage. Of Moroccan provenance, Martin Gardner and Tom Christian introduced the species from the Rif Mountains in 2015, under numbers CAGM 61 and 79. Three plants under the latter number are growing well at Eastnor Castle, and seemingy similar to those of McB 2568, appear to be developing a ‘messy habit’ (T. Christian, pers. comm. 2020). Examples of CAGM 61 and 79 are also establishing well at Westonbirt.