Shrub mostly 1-5 m tall. Leaves more or less in pairs, alternating at right angles, to 3 cm long, 5 mm wide, lanceolate to obovate, margins mostly with a few paired incisions. Flower clusters lateral, branched. Flowers white to bluish. Sometimes confused with h. odora but with only a few marginal leaf teeth.

New Zealand

 

H. odora (Hook. f.) Ckn, Boxwood, from New Zealand is a variable, rounded shrub to 1 m or more tall. Leaves 1-2 cm long, elliptic to ovate, Buxus-like in size and also dark green and glossy above, margin with numerous close-set, minute teeth, leaf bud with a shield-shaped sinus. Flower clusters mostly terminal, cone-shaped, spring and summer. Flowers stalkless, in opposite pairs, white. [H. buxifolia (Benth.) Ckn & Allan]

H. venustula (Col.) L.B.Moore from New Zealand is a rounded shrub to 1m or so tall with yellow-green stems. Leaves 1-1.5 cm long, 5-8 mm wide, ovate to obovate, leathery, on short stalks. Flower clusters lateral, to about 3 cm long, abundant. Flowers white; early summer. [H. laevis (Benth.) Ckn, 'Laevis']

Source: Spencer, R. (2002). Scrophulariaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.