An evergreen tree, 80 to 100 ft high in favourable situations in California, with a dense head of very leafy branches; young shoots at first minutely downy. Leaves alternate, leathery, with a pungent aromatic odour when crushed, narrowly oval or oblong, but tapered at both ends, 2 to 5 in. long, 3⁄4 to 11⁄2 in. wide, not toothed, dark green and glossy above, paler beneath, almost glabrous on both surfaces except when just unfolding. Flowers 1⁄4 in. across, yellowish green, produced during April in terminal and axillary umbels 3⁄4 in. wide, on a common stalk 1 in. long. Fruit roundish pear-shaped, 1 in. long, 3⁄4 in. wide; green changing to purplish. Bot. Mag., t. 5320.
Native of Oregon, from Douglas Co. southward, and of California, where it occurs throughout the coastal range almost to the Mexican border and is also found in the Sierra Nevada. The best stands occur in moist valley bottoms, but most of these have given way to cultivation. At the other extreme, it occurs at high elevations as a stunted, even prostrate shrub. All parts of the plant are aromatic, and the leaves give off a volatile oil which can cause sneezing and headache – even, it is said, unconsciousness – if sniffed too long and deeply. It may also cause skin irritation in some persons. The timber, which is heavy and often beautifully figured, was used in cabinet work and for panelling.
U. californica was discovered by Menzies in 1792, and introduced by David Douglas, who met with it in a deep and shady side-valley of the Umpqua river of Oregon in October 1826, and felled a tree to obtain the seeds. This fine tree is hardy in the open at Kew, being only occasionally injured by severe frost. On a wall it has flowered there, and borne fruit. It likes a sheltered spot, and is about equal to the bay laurel as an ornamental evergreen. The tree at Kew, near the Temperate House, mentioned in previous editions as 32 ft high, measures 52 × 73⁄4 ft (1967). Other notable specimens are: Warnham Court, Horsham, Sussex, 55 × 6 ft + 51⁄4 ft (1969); Nymans, Sussex, 40 × 71⁄4 ft (1966); Borde Hill, Sussex, 51 × 81⁄4 ft (1973, cf. 25 × 21⁄2 ft in 1934); Langley Park, Slough, 41 × 41⁄4 ft (1974); Mount Usher, Co. Wicklow, Eire, 42 × 73⁄4 ft (1975).