autumn or winter. Leaves (Plate 206, Fig. 19), about 6 inches long and 8 inches wide, cordate at the base, deeply five-lobed ; lobes, oblong or ovate, acuminate at the apex, each with three or four small teeth on the margin, which is neither serrate nor ciliate; sinuses, reaching two-thirds the length of the leaf, acute at the base ; upper surface dark green, shining, glabrous ; lower surface light green, glabrous, except for conspicuous tufts of reddish-brown pubescence in the axils of the primary and secondary nerves; petioles without milky sap.
Flowers, appearing with the leaves, in erect, long-stalked corymbs; bracts and bracteoles conspicuous, 1⁄5 inch long; filaments glabrous, ovary pubescent. Fruit, ripening in autumn; keys 13⁄4 inch long, narrowly divergent; carpels scurfy pubescent when young, glabrous when mature ; wings broad.
The leaves are variable as regards the depth of the sinuses, being described by Medwedjeff as either five-lobed or five-partite ; and the description above applies to the deeply-cut form, which is in cultivation.
The foliage resembles in size and shape some forms of the sycamore, but can be readily distinguished by the margin being simply dentate and not serrate. The buds are also different. In winter the terminal buds are ovoid, obtuse, with six outer scales, the lower pair of which are shining, dark red and glabrous, with the middle and upper parts ciliate; lateral buds distinctly stalked, arising at an acute angle; twigs polished, dark red, glabrous.
This species was discovered by Radde' in 1864 in the Caucasus at an elevation of 6000 feet, and was at first identified by Trautvetter with A. platanoides, which it resembles in no respect. It is allied to A. insigne, and has a more westerly dis- tribution than that species, growing on both sides of the main chain of the Caucasus, but not extending into Talysch or Persia. It is a tree of high elevations, growing at 6000 to 8000 feet altitude in company with birch and subalpine shrubs, or mixed with Abies Nordmanniana on the edges of alpine meadows, and flowers in May. It ascends in many places to the timber line, and at lower levels is replaced in the forests by the Norway maple.? According to Wolf the tree attains 50 feet in height and 6 feet in girth; but Radde’ gives the measurement of a tree, probably of this species, which was 120 years old and 62 cubic feet in volume.
This species was raised in van Volxem’s nursery from seeds collected in 1866 by Balansa in Lazistan, and for a long time was confused with A. insigne,® being described and figured under that name in the Botanical Magazine. Van Volxem informed Sir J. Hooker that it was the hardiest of the eighty species and varieties of maple cultivated by him, having withstood without injury the disastrous winters of 1879-80 and 1880-81 ; and being a late grower, it had never even been nipped by spring frosts. At Kew, where there are two healthy trees, it is one of the latest maples to come into leaf. The tree sent by van Volxem to Dr. Masters flowered
1 Pflanzenverb. Kaukasusländ, 108, 175, 225, 310 (1899).
2 Ibid. 245. Radde speaks of A. platanoides and A. Trautvetteri growing together in impassable thickets, which are beaten down by the heavy snow.
3 A. Trautvetteri has also been confused with A. Volxemi, as in Gard. Chron. x. 188, note, and 189 (1891). Rehder, in Cycl. Am. Hort. 15 (1890), agrees with me that the tree, figured in Bot. Mag. 6697, is the true A. Trautvetteri, though it differs from wild specimens preserved in the Kew herbarium, in having the leaves more deeply cut.
