Flora of New Zealand Series

red oak

Large deciduous tree (to c. 25 m tall in cultivation); bark rough and fissured. Shoots dark reddish brown or brown, glabrous, with prominent lenticels. Buds glabrous, without surrounding stipules; apex sometimes hairy. Petiole to 6 cm long. Stipules soon caducous. Lamina on adult shoots mostly 11-20 × 7-15 cm, ovate or ovate-oblong, with 3-5 pairs of lobes extending ⅓-⅔ distance from apex to midrib, slightly shining above, turning deep red before falling, usually glabrous, subcoriaceous, sometimes with a few brownish hairs in vein axils beneath; lobes with aristate apex, usually with 1-4 aristate teeth, sometimes entire; base cuneate. ♂ catkins to c. 8 cm long; lower fls distant; rachis with curly hairs; perianth 1.7-2.3 mm long, with curly hairs on margin; stamens 3-5. Fruiting peduncles 1-1.5 cm long, with 1-(2) fertile frs; frs reaching maturity in second year. Cup 1.5-2 cm diam., shallow; scales ovate, appressed, glabrous or minutely puberulent. Acorn 2-2.5 cm long, ovoid, c. 1/4 enclosed by cup.

N.; S.: S. Canterbury.

Eastern N. America 1988

Acorns are freely produced by cultivated trees and occasionally young self-sown trees grow in their vicinity, particularly in untended or ungrazed areas around parks and plantations.

FL Oct.

Red oak is widely planted in parks, domains and larger gardens in many towns and cities. It is often confused with 2 other American oaks of subgen. Erythrobalanus. The most closely related is Q. coccinea Muenchh., scarlet oak, which has more deeply lobed lvs, prominently shining above, and becoming even more brightly coloured in the autumn. The frs of these 2 spp. are very similar. The second sp., Q. palustris Muenchh., pin oak, is easily the commonest of the 3 in N.Z. but the trees are the least likely to have self-sown seedlings growing in their vicinity. Pin oak generally has smaller lvs than the other 2 spp., the lf lobes extend > 3/4 of the distance to the midrib on reproductive shoots, the axillary hair tufts are more conspicuous and the cup is smaller and even shallower than in Q. rubra. Q. rubra is often known in N.Z. as Q. borealis.