Cytisus scoparius
Poisonous plant
Environmental Weed (2024)
Common names
wild broom
Biostatus
Exotic
Conservation status
Not applicable
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Red/Pink, Yellow
Detailed description
Much-branched deciduous shrub up to 2m high; twigs glabrous, but sericeous when young, green, more or less 5-angled. Leaves variable, usually glabrous above and sericeous below, and 3-foliolate and petiolate when mature or on older twigs; leaves of younger twigs often 1~2 foliolate and subsessile; young leaves often sericeous above and below but sometimes glabrous; leaflets apetiollate, elliptic to obovate, usually acute, sometimes emarginate, 4~16mm long; terminal leaflet > lateral leaflets. Flowers usually solitary, rarely paired, axillary; pedicels 5~13mm long. Calyx glabrous, bilabiate, about quarter the length of corolla; upper and lower lips entire or shallowly toothed. Corolla usually golden yellow, rarely partly red or tinged mauve, 16~25mm long. Pod black, oblong, many seeded, 15~60mm long with hairy margins; seeds brown or greenish-brown, ellipsoid, compressed, about 3mm long. (- Webb et. al., 1988)
Similar taxa
An erect shrub up to c. 2-4m tall, with green, switch-like stems longitudinally ridged and angled (Wilson & Galloway 1993). The shrub is much-branched (Porteus 1993). Leaves are sparse mostly narrow and simple. The flowers are generally bright yellow and 2.5cm in length The pod is black when ripe and produces and explodes loudly on warm days, scattering the seed. The plant is perennial and has a stout taproot.
Habitat
Terrestrial. A plant of lowland and montane habitats. Plant occurs in sites with low-moderate-high fertility. The plant normally grows in areas of high rainfall, on acid soils but never on chalks. Plant grows in shrubland, tall tussockland, short tussockland, cliff, bluff and riverbed communities (Timmins & MacKenzie 1995). The plant grows in disturbed lowland and montane habits such as pasture, waste ground, riverbeds and poorly grazed areas.
Detailed taxonomy
Genus
Family
Endemic family
No
Ecology
Flowering
September, Ocrtober, November, December
Fruiting
December-January, later in cooler areas (Timmins & MacKenzie 1995).
Year naturalised
1872
Origin
Eurasia
Reason for introduction
Ornamental.
Tolerances
The plant is tolerant to drought and shade and highly tolerant to frost. The plant is intolerant to poor drainage. Physical damage to the plant results in resprouting, if not severe, although fire will kill plants. Heavy grazing will kill the plant, resprouting will occur after light grazing. Seedlings tolerate a wide range of soil conditions. Young plants can tolerate a wide range of light intensity and survive even in 90% shade. The plant is tolerant of dry, stoney conditions and has the ability to spread rapidly in the absence of grazing. Leaves are unpalatable. The plant tolerates a wide range of soil conditions.
Life cycle and dispersal
Perennial. Seeds germinate readily, under a variety of conditions, in both autumn and spring. Seedlings develop slowly during the first year and plants do not flower until at least 2 years old. Plants are thought to live for 10-15 years. Plants found that were >20 years old (Hayes, 1998). The deeper the seed is buried the longer it appears to survive (Hayes, 1997). After 13 years about 2/3 of seed buried 15cm was intact but only 1/3 of seed buried at 3cm. Nearly all the seed remaining after 13 years was viable (Research by H. Harman and P. Syrett in Hayes, 1997). Seeds prolifically. The pod produces 9 seeds/pod and usually in excess of 2 000 pods/bush and forms a substantial seed bank. Seeds persist in seed bank (Atkinson 1997). Seed is dispersed by the plants explosive pod (Timmins & MacKenzie 1995) on hot days. The seeds can be spread by gravel, mud, animals, agricultural produce, machinery, people, tracks and railroads, roads and water. Small plants (0.5 m, 2 years old) flung seeds up to 1.5m away (Hayes, 1997)
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACU: Facultative Upland
Occasionally is a hydrophyte but usually occurs in uplands (non-wetlands).
Other information
Poisonous plant
The seeds of this broom species are poisonous. This is especially true if the seed are crushed or chewed before being swallowed.
Etymology
cytisus: From the Greek kytisos ‘trefoil’, referring to the shape of the leaves of many species
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.
NVS code
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.
CYTSCO