Acacia mearnsii
Common name
black wattle
Family
Fabaceae
Flora category
Vascular – Exotic
Structural class
Trees & Shrubs - Dicotyledons
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.
ACAMEA
Conservation status
Not applicable
Habitat
Waste places, scrubland, pasture, riverbanks
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).
Features
Shrub to large tree, twigs ribbed or angled. Leaves 2-pinnate, pinae in 9-18 pairs, pinnules close-set, dark green and in 20-60 pairs. Inflorescence consists of many pale creamy yellow globbose heads arranges in racemes. Seed pod straight or somewhat curved, up to 90 x 7 mm, usually constricted around each seed.
Similar taxa
A. mearnsii is easily distinguished by the dark green foliage, creamy yellow flowers and the most pinnules of all the 2-pinnate wattles naturalised.
Flowering
July, August, September
Flower colours
Cream, Yellow
Year naturalised
1981
Origin
S.E. Australia, Tasmania
Etymology
acacia: Derived from Greek ‘akazo’ to sharpen, meaning point; spine or thorn.
Reason For Introduction
Ornamental
Life Cycle Comments
Perennial. seeds have been known to germinate after 90 years.
Reproduction
Seed is produced in large numbers in dark brown pods. Seed viability is estimated at 50 years. Mass germination is likely following fire, or mechanical disturbance. Saplings may coppice if cut, but does not sucker.
Seed
Seed is produced in large numbers in dark brown pods. Seed viability is estimated at 50 years. Mass germination is likely following fire, or mechanical disturbance.
Dispersal
Spread by people for firewood and as an ornamental tree. Seed dispersed locally by wind and gravity.
Tolerances
Can tolerate dry conditions and frosts to about -7 degrees.