Lupinus arboreus
Poisonous plant
Environmental Weed (2024)
Common names
tree lupin
Biostatus
Exotic
Category
Vascular
Structural class
Trees & Shrubs - Dicotyledons
Flower colours
Yellow
Detailed description
Short-lived, perennial shrub to 2-3 m high. Deep taproot. Stems densely silky-hairy when young, tough, erect, branching, becoming soft-woody. Leaves grey-green, hairless above, silky below, divided into 5-11 leaflets spreading out from one point finger-like; leaflets 15-40 x 3-10 mm. Flowers pea-like, 15-18 mm long, usually pale yellow (rarely white or bluish), sweetly scented, Oct-May. Seed pod stout, softly hairy, 40-80 mm long, firmly attached; splits explosively to disperse dark brown, mottled seeds, 4-6 mm long.
Similar taxa
L. angustifolius blue lupin is a semi-woody annual with blue flowers Aug-Apr, occasionally weedy. L. polyphyllus herbaceos weedy species with blue flowers. Hybrid L. arboreus x polyphyllus has larger and more leaflets, flower yellow with blue or purple streaks; is rarely weedy.
Habitat
Terrestrial. Short tussockland, bare land, riverbeds, coastal sandy and well drained areas.
Conservation status
Not applicable
Detailed taxonomy
Family
Fabaceae
Ecology
Flowering
October, November, December, January, February, March, April, May
Year naturalised
1899
Origin
California, N. America
Reason for introduction
Ornamental
Tolerances
Tolerates wind, salt, hot to cold, physical damage and grazing (not readily eaten), drought, low fertility (fixes nitrogen), fire. Intolerant of moderate shade and waterlogged soils.
Life cycle
Perennial. Reproduces by seed which can last in the soil for a long time. Dispersed by water and soil movement. Explosive pods. Deliberately sown for sand consolidation, erosion control.
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]
UPL: Obligate Upland
Rarely is a hydrophyte, almost always in uplands (non-wetlands).
Other information
Poisonous plant
The seed are poisonous if they are chewed or crushed before eating.
Etymology
arboreus: From the Latin arbor ‘tree’, meaning tree-like
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.
LUPARB