A small tree or large shrub with downy branchlets. Leaves five-lobed (more rarely seven-lobed), 3 to 5 in. long and as much wide, cordate at the base, covered beneath with a yellowish down; lobes tapered at the apex, ovate or triangular, margins sharply toothed and incised. Flowers in upright, slightly compound, hairy racemes. Wings of fruit almost upright; keys slightly downy or glabrous, about 3⁄4 in. long.
Native of the mountains of Japan and of N.E. Asia; date of introduction uncertain, but later than 1881. It is closely related to the east American A. spicatum, of which Maximowicz made it a variety; but in that species the leaves are usually only three-lobed.
A. multiserratum Maxim. A. caudatum var. multiserratum (Maxim.) Rehd.; A. erosum Pax – A closely allied species and a common tree in China from Kansu to Yunnan; the chief point of distinction is that the leaves are nearly glabrous beneath at maturity. Introduced by Wilson in 1907, but rare in gardens.
These two maples are closely allied to a Himalayan species which Rehder refers to A. caudatum Wall. Unfortunately this is a very confused name and has been abandoned in this work in favour of A. papilio (q.v.).
A. nipponicum Hara A. parviflorum Franch. & Sav., not Ehrh.; A. brevilobum Hort. Hesse. – A rare species in the wild state, native of Japan, allied to A. ukurunduense. Leaves 4 to 6 in. long, slightly more wide, shallowly five-lobed, sharply double-toothed (in its ally the toothing is coarser and more irregular); veins beneath covered with a rusty down. Distributed by Hesse’s nurseries as A. brevilobum. It is in cultivation at Dawyck, Peebl.