Chrysanthemoides monilifera subsp. monilifera
NPPA pest plant
Environmental Weed (2024)
Common names
boneseed, bitou bush
Biostatus
Exotic
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Yellow
Detailed description
Bushy, semi-woody, much branched shrub or small tree to 2-3 m. Young stems ribbed and woolly, becoming smooth. Leaves alternate, smooth, leathery, entire, 70 x 35 mm, margins irregularly toothed. Bright yellow daisy-like flowers, 25-30 mm diam, Sep-Feb. Fruit an oval green drupe, 6-9 mm, hard with thin fleshy covering, turning black, with very hard seed.
Similar taxa
The other subspecies (C. monilifera subsp. rotundata) is very weedy in Australia, but not known to be present in NZ. It has a more prostrate habit, has rounder leaves, and the flowers have more than 12 petals. Foliage is superficially similar to Dimorphotheca (Osteospermum fruticosum) but the habit and flowers of these plants are very different.
Habitat
Terrestrial. mainly coastal areas, coastal cliffs, inshore islands, dry shrublands, shrubland margins, consolidated sand dunes, gumlands, roadsides, quarries, wastelands, exotic plantations and a threat to offshore islands.
Conservation status
Not applicable
Detailed taxonomy
Family
Asteraceae
Synonyms
Osteospermum moniliferum L.
Ecology
Flowering
September, October, November, December, January, February
Year naturalised
1870
Origin
S.W. Cape area, South Africa
Reason for introduction
Ornamental
Tolerances
Intolerant to shade and poor drainage and tolerant to drought. Fire kills plants but assists germination of seeds and the plant is reasonably tolerant to other physical damage. It is tolerant of low soil fertility, poor soils and sand.
Life cycle and dispersal
Perennial. Suspected seed bank viability extensive because seed is covered in hard coating i.e. bone-seed. Primarily reproduces via seed but vegetative reproduction is possible if stems come into contact with the soil. A mature bush can produce up to 50,000 seeds per year. Research indicates that 6-13% seeds remain viable after 3 yrs of burial with numbers increasing depending on depth of burial (Weiss 1984). Initially just over half the seeds are viable and can remain dormant inside the unsplit seed coat for up to 10 years. Seed is dispersed by birds, possums, humans and mammals.
Other information
Etymology
monilifera: From the Latin monilis ‘necklace’ or ‘collar’ and ferre ‘to bear’
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.