Flora of New Zealand Series

broom

Much-branched deciduous shrub up to 2-(2.5) m high; twigs glabrous, but sericeous when young, green, ± 5-angled. Lvs variable, usually ± glabrous above and sericeous below, and 3-foliolate and petiolate when mature or on older twigs; lvs of younger twigs often 1-2-foliolate and subsessile; young lvs often sericeous above and below but sometimes glabrous; leaflets apetiolulate, elliptic to obovate, usually acute, sometimes emarginate, 4-16-(20) mm long; terminal leaflet > lateral leaflets. Fls usually solitary, rarely paired, axillary; pedicels (3)-5-13 mm long. Calyx glabrous, bilabiate, c. 1/4 length of corolla; upper and lower lips ± entire or shallowly toothed. Corolla usually golden yellow, rarely partly red or tinged mauve, 16-25 mm long. Pod black, oblong, many-seeded, 15-60 mm long, with hairy margins; seeds brown or greenish brown, ellipsoid, compressed, c. 3 mm long.

N.: throughout; S.: throughout; St.: Halfmoon Bay, mouth of Lords R.; Ch., C.

Europe, Asia Minor, Russia 1872

Waste places, scrubland, riverbeds, coastal areas.

FL Sep-Apr.

Broom is a widespread and troublesome weed in many areas of N.Z., particularly in less intensively farmed hill country and riverbeds. Williams, P. A., New Zealand J. Bot. 19: 31-43 (1981), gave details of the ecology of broom in Canterbury; many of his experimental results undoubtedly apply to broom throughout N.Z.

Cultivated forms with a partly red standard, and also sometimes the keel and wings tinged red to reddish brown, are occasionally naturalised; the name C. scoparius f. andreanus is sometimes applied to these plants. Broom has been known in N.Z. as Sarothamnus scoparius and Spartium scoparium.