A small tree to 20 ft in the wild state, or a many-stemmed shrub. Young shoots grey-green or yellowish but ultimately becoming striped after the fashion of the snake-bark group. Leaves roundish-ovate, 2 to 21⁄2 in. long, 11⁄2 to 2 in. wide, heart-shaped at the base, palmately three-veined, triangular-ovate in outline, usually with two small, spreading, sharply acuminate lobes; margins sharply saw-toothed; undersides rusty-pubescent near the base but soon glabrous. Flowers in pendulous racemes. Wings of fruit curved, spreading at an obtuse angle or almost horizontally.
Native of China; discovered by the missionary Giraldi in Shensi and introduced to Kew from the Arnold Arboretum in 1927. In some of its forms A. grosseri has almost unlobed leaves, and is then difficult to distinguish from A. davidii. However, the toothing of the leaves is always sharper than in that species, and the leaves smaller and proportionately wider.
var. hersii (Rehd.) Rehd. A. hersii Rehd. – Discovered by Hers in 1919 in Honan province; introduced by him to the Arnold Arboretum in 1923 and thence to Kew a few years later. From the type it differs mainly in the more distinct lobing of the leaves; the lateral lobes, borne above the middle of the leaf, are tapered at the apex into a long point.
For garden purposes there is little to choose between the type and the variety. Both colour red in the autumn and have the beautiful striped bark of their group. But in the colder winters of New England the variety has proved to be the hardier, and certainly, both in Britain and the United States, it is commoner in gardens than the type.
At Kew typical A. grosseri is represented by a specimen of 16 × 3⁄4 ft, while var. hersii is 31 × 31⁄2 ft (1967). There are several specimens of the variety at Westonbirt, the tallest, pl. 1936, 40 × 11⁄2 ft (1966).
From the Supplement (Vol. V)
This is placed under A. tegmentosum by Edward Murray, as A. tegmentosum subsp. grosseri (Pax) E. Murray. But de Jong (op. cit., p. 144) considers that it is better grouped with A. davidii.
The example at Kew in the Maple Collection was raised from seeds collected by Joseph Rock under his number 15053.
var. hersii - specimens: Kew, Maple Collection, from the original introduction by Hers, 33 × 31⁄4 ft (1981); R.H.S. Garden, Wisley, Surrey, on Battleston Hill, 52 × 4 ft (1975); Wakehurst Place, Sussex, Golf Ground Extension, pl. 1936, 52 × 4 ft (1981); Westonbirt, Glos., two trees pl. 1942, 46 × 33⁄4 ft at 2 ft and 42 × 31⁄4 ft at 2 ft (1981); Talbot Manor, Norfolk, pl. 1948, 39 × 4 ft (1978).