Acer negundo L.
box elder
Dioecious tree to c. 17 m high, deciduous, very widespreading; trunk becoming stout and gnarled. Shoots glaucous, glabrous. Lvs compound; leaflets 3-5-(7); petioles to 12 cm long. Leaflets very variable in shape and size, petiolulate or sessile; terminal leaflet usually to 15 × 8 cm, ovate; lateral leaflets often lanceolate-ovate, remaining hairy on veins below and sometimes on midrib above, coarsely crenate-serrate, sometimes lobulate; apex acute to acuminate. Fls appearing before lvs. ♂ infl. corymbose; pedicels long, filamentous, hairy, pendulous, pinkish. Sepals and petals 0.5-1 mm long, hairy or nearly glabrous. Stamens prominently exserted; filaments very short; anthers 2-4 mm long. ♀ infl. a pendulous raceme; pedicels very slender. Samara wings c. 2.5 cm long, broad, ± incurved, diverging at an acute angle. Seed c. 1.5 cm long, narrow.
S.: Blenheim, Christchurch.
E. and C. North America 1983
Vicinity of gardens, parks and domains.
FL Sep-Nov.
Box elder is very common in cultivation, especially in the South Id. ♀ trees fruit prolifically and spontaneous plants often occur. Cv. 'Variegatum', with broad white-margined lvs, is the usual form planted but it nearly always reverts to the ordinary green-leaved form unless such branches are removed. All plants collected wild were green-leaved and can be referred to var. negundo.
