Scientific name: Verbena bonariensis L.

Common names: Purple top

Family: Verbenaceae

Origin: 

Native of South America.

Habit:

An erect perennial herb growing from 0.6-1.5 m in height and sometimes with a woody base.

Habitat:

Common weed of coastal areas often found in pastures, cultivation, roadsides and untended areas.

General description:

Stems and leaves

Stems are square in cross-section. The leaves are opposite, attached to the stems without stalks (ie. sessile) and have narrowly oval or oblong blades (4-13 x 1-4.5 cm in size) with a point at the tip.  The margins of the leaves are irregularly toothed, especially near the tip of the leaf.  Plants are coarse hairy and rough to the touch.

Flowers and fruit

The flowers are small and tubular with purple petals.  Flowers are borne in branched finger like inflorescences at tips of the stems.  Individual flower spikes are dense, 1-4 cm long.  Flowering occurs mostly in summer and autumn.  Fruits separate into 4 individual nutlets.

Distinguishing characteristics:

Perennial herb with erect quadrangular stems growing 0.6-1.5 m tall with purple tubular flowers in spikes. This species is similar to Verbena officinalis (common verbena). Verbena bonariensis can be distinguished  from this species by its leaf attachment, since its leaves are sessile (without stalks) and Verbena officinalis leaves have short leaf stalks.

Noxious status:

Not noxious.

Sources:

Kleinschmidt, H.E., Holland, A. and Simpson, P. (1996). Suburban Weeds. 3rd Edition. Department of Primary Industries, Brisbane.

Stanley, T.E. and Ross, E.M. (1983-1989). Flora of South-eastern Queensland. Volume 2. Department of Primary Industries, Brisbane.

Auld, B.A. and Medd, R.W. (1996). Weeds: An Illustrated Botanical Guide to Weeds of Australia. Inkata Press, Sydney.