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Quercus macrocarpa Michx.

Burr Oak

Modern name

Quercus macrocarpa Michx.

A deciduous tree 80 to 170 ft high in the wild; bark with prominent, fairly firm ridges; young shoots and buds downy. Leaves obovate, 4 to 10 in. (sometimes 1 ft) long, about half as wide, wedge-shaped at the base, five- or seven-lobed, the terminal lobe often large (consisting of about half the leaf), ovate and itself wavy-lobed, the lower lobes often reach almost to the midrib, dark green, glabrous and glossy above, covered beneath with a pale, dull, minute felt; stalk up to 114 in. long, downy. Acorn 34 to 112 in. long, usually solitary, about half enclosed in a cup distinguished by having the scales near the rim almost thread-like and forming a fringe, on account of which this tree is often known as the ‘mossy-cup oak’.

Native of eastern N. America; introduced in 1811. It is very similar to Q. bicolor, but is distinguished by the more deeply lobed leaves, and especially by the acorn cup. Like all the white oaks of America, it is not very happy in our climate, but there are a few healthy trees at Kew, the largest of which, near the Ash collection, measures 67 × 634 ft (1967). In the Oak collection there are two specimens: pl. 1871, 52 × 534 ft; pl. 1874, 56 × 412 ft (1972).

Q. lyrata Walt. – This is sometimes though rarely seen in gardens, and is not suited to our climate. It is allied to Q. macrocarpa, but its acorn is distinguished by being almost or entirely enclosed in the cup. The leaves are obovate, deeply five- to nine-lobed, the largest 7 to 9 in. long, nearly half as wide, dark green and glabrous above, pale and downy beneath; stalk up to 34 in. long. Native of the southern United States, where it is occasionally 100 ft high; introduced in 1786.

It is known as the ‘overcup oak’.

From the Supplement (Vol. V)

specimens: Kew, near Ash Collection, 69 × 7 ft (1973), in Oak Collection, pl. 1871, 52 × 534 ft and, pl. 1874, 56 × 412 ft (1972); Holland Park, London, 85 × 712 ft (1986); Tilgate Park, Sussex, 82 × 712 ft (1984).



Other species in the genus