T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Baccharis halimifolia (Groundsel bush)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Baccharis
Species: B. halimifolia
Binomial name: Baccharis halimifolia
Common name: Eastern baccharis, Silverling, Sea myrtle, Manglier, Consumption weed, Saltbush, Groundsel bush, Cotton-seed tree, Baccharis, Marsh Groundsel.

Baccharis halimifolia is a North American species of shrubs in the sunflower family. It is native to Nova Scotia, the eastern and southern United States, eastern Mexico the Bahamas and Cuba. This species has also become naturalised in New Zealand were it inhabits disturbed forest, coastal swampland, degraded pasture. It prefers warm, humid conditions and will tolerates a wide range of soil conditions. Baccharis halimifolia is toxic to livestock because the leaves and flowers contain a cardioactive glycoside. This causes staggering, trembling, convulsions, diarrhea, and other gastrointestinal symptoms. It will invade pastures because grazing animals will not eat it.

Baccharis halimifolia is an erect, densely branched deciduous shrub >2.5 m tall, sometimes single-stemmed from the base and tree-like. Its simple, alternate, thick, waxy,egg-shaped to rhombic, dull green leaves are 2-6 cm long, smooth-margined or with 1 tooth or 1-3 pairs of coarse teeth on the upper margins, the surfaces slightly resinous, usually with small dots.
Baccharis halimifolia is dioecious, with male and female flowers on separate individuals. The flowers are borne (March-May) in numerous small, compact heads in large leafy terminal inflorescences, with the snowy-white, cotton-like female flower heads that are conspicuous at a distance. The long, thin seeds are straw-coloured with tufts of fluffy hairs that assist their windblown dispersal. They are also dispersed by water, machinery, in agricultural produce and gravel etc.