Acacia cultriformis A.Cunn. ex G.Don

Knife acacia (en), Grand-Mimosa couteau (fr)

Species

Angiosperms > Fabales > Fabaceae > Acacia

Characteristics

Shrub to c. 4 m high. Branchlets normally lightly to conspicuously pruinose, glabrous. Phyllodes rather crowded, inequilateral, often ±triangular, broadest about the middle, with abaxial margin ±straight and adaxial margin markedly rounded or angled, 10–30 mm long, 5–15 mm wide, coriaceous, grey-green to glaucous, light green when young, glabrous; midrib central or excentric; lateral veins not prominent; gland rather prominent, at or slightly below widest part of phyllode. Racemes prolific in upper axils; axes 1–5 cm long, sometimes to 20 cm long, glabrous; peduncles 2.5–5 mm long, glabrous; heads globular to shortly cylindrical, 13–40-flowered, bright golden. Flowers 5-merous; sepals united. Pods narrowly oblong, raised over seeds, to 9 cm long, (4–) 5–8 mm wide, firmly chartaceous, often pruinose, glabrous. Seeds longitudinal, oblong, 3.5–4.5 mm long, dull to slightly shiny, black; aril ±clavate.
More
Unarmed shrub to c. 4 m. Branchlets regular, glabrous. Phyllodes crowded along branches, coriaceous, lower margin straight or slightly curved, upper margin sharply curved, glabrous, 2-3 by 1-1.4 cm, 2-2.5 times as long as wide, glabrous, gland at or slightly below the broadest part of the phyllode, pustular, with a rather large orifice, main vein close to the lower margin, reticulation penni-veined. Inflorescence consisting of heads of 25-35 flowers in axillary glabrous racemes. Flowers pentamerous, bisexual. Pod flat, glaucous, raised over the seeds, 5-7 by 0.7 cm. Seeds longitudinal, 3.5 by 2.3 mm; areole almost closed, funicle not folded but thickened into a clavate aril beneath the seed.
Unarmed shrub or small tree; young branchlets angular, glabrous. Leaves phyllodic, apparently simple, 0.8-3 x 0.6-1.1 cm, obliquely obovate-lanceolate to ovate-triangular, glaucous, glabrous, with a single main longitudinal nerve and finely penninerved, usually with 1 marginal gland, sometimes on a prominent angle. Flowers in small round heads, arranged in axillary racemes which are longer than the phyllodes and are often ± aggregated terminally. Pods 5-9 x 0.5-0.7 cm, linear-oblong, glabrous, longitudinally dehiscent.
Leaves glaucous, phyllodic, apparently simple, 0.8-3 x 0.5-1.1 cm., obliquely obovate-lanceolate to ovate-triangular with the apex of the triangle on the upper margin, glabrous.
Flowers yellow, in heads arranged in axillary racemes which are larger than the leaves and often ± aggregated terminally.
Shrub, unarmed; young branchlets glabrous, angular.
Life form perennial
Growth form shrub
Growth support free-standing
Foliage retention evergreen
Sexuality hermaphrodite
Pollination entomogamy
Spread -
Mature width (meter) 1.5 - 2.5
Mature height (meter) 4.0
Root system -
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer
Photosynthetic pathway c3

Environment

Rocky ridges. Dry sclerophyll forests and heath. Grows in sand or clayey loam in Eucalyptus communities. Woodland, heath and mallee, often in rocky sites.
More
Grows in sand or clayey loam in Eucalyptus communities.
Light 7-9
Soil humidity 1-6
Soil texture 1-6
Soil acidity 3-8
Soil nutriment -
Hardiness (USDA) 9-10

Usage

Widely cultivated; the cultivar A. cultriformis ‘Cascade’ has a loose, pendulous growth habit, reaches 0.3 m tall and spreads to 2–4 m, according to W.R. Elliot & D.L. Jones, Encyclopaedia of Australian Plants 2: 37 (1982) and M. Hitchcock, Australian Plants 22: 324–325 (2004).
Uses dye erosion control medicinal wood
Edible flowers
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by cuttings or seedlings. Seeds needs soaking.
Mode cuttings seedlings
Germination duration (days) 21
Germination temperacture (C°) 21 - 26
Germination luminosity -
Germination treatment soaking
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Habit

Acacia cultriformis habit picture by Trap Hers (cc-by-sa)

Leaf

Acacia cultriformis leaf picture by Trap Hers (cc-by-sa)
Acacia cultriformis leaf picture by Trap Hers (cc-by-sa)

Distribution

Acacia cultriformis world distribution map, present in Argentina, Australia, Brazil, Ethiopia, Indonesia, India, New Zealand, United States of America, South Africa, and Zimbabwe

Conservation status

Acacia cultriformis threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:470087-1
WFO ID wfo-0000191942
COL ID 8P3N
BDTFX ID 86
INPN ID 79689
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Acacia scapuliformis Acacia glaucophylla Acacia papuliformis Acacia cultriformis Acacia glaucifolia Racosperma cultriforme Acacia scapuliformis Acacia cultriformis var. albicans Acacia cultriformis var. glaucescens