Species

Ageratina riparia

Etymology

riparia: From the Latin ripa 'streambank or 'riverbank' and the suffix -aris which gives the sense 'belonging to' or ' resembling'. Riparia means growing on the banks of streams or rivers

Common Name(s)

mist flower

Family

Asteraceae

Flora Category

Vascular - Exotic

NVS Species Code

AGERIP

The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.

Structural Class

Dicotyledonous Herbs - Composites

Habitat

Terrestrial. Humid subtropical and tropical rainforests (W.T. Parsons & E.G. Cuthbertson 2001). In NZ, coastal, lowland (Timmins & MacKenzie 1995). Forest margin, damp banks and streamsides, slips (Timmins & MacKenzie 1995). In Australia, shaded riverbanks, steep south facing hillsides in areas where annual rainfall exceeds 1700mm (W.T. Parsons & E.G. Cuthbertson 2001).

Features

Erect or sprawling, many-stemmed herb to subshrub to 0.5-1.5 m. Perennial fibrous rootstock. Stems occ die back in winter, covered in purple-striped non-sticky hairs, usually purple, becoming woody, with branches in opposite pairs. Leaves in opposite pairs, 60-100 x 15-25 mm, willow-like, coarsely serrate except near base. Flowers small, white, 4-5 mm diam, in terminal clusters, Aug-Jan. Seeds black, 5-angled, 2 mm long.

Similar Taxa

Distinctive toothed leaves separate mistflower from Mexican devil

Flowering

August, September, October, November, December, January, February, March

Flower Colours

White

Fruiting

June-September (W.T. Parsons & E.G. Cuthbertson 2001)

Year Naturalised

1931

Origin

Mexico, W. Indies

Reason For Introduction
Ornamental

Life Cycle Comments
Perennial.

Reproduction
Reproduces by seed. Plants may re-grow following disturbance if roots (occasionally stems) contact ground. Drooping stems can layer in wet sites.

Seed
Many seeds produced.

Dispersal
wind, water, road mowing machines (Timmins & MacKenzie 1995).

Tolerances
Tolerant of deep shade and damp, damage and grazing, salt, most soils

This page last updated on 18 Jan 2010