Black Wattle

Names and Synonyms

Common Names

• wattle
• black wattle
• green wattle
• late black wattle
• tan wattle

Scientific Names

Accepted name

Synonyms

• Racosperma mearnsii
• Acacia decurrens var. mollissima

Regional and Traditional Names

Sources: Wikidata, Catalogue of Life

Taxonomical Classification

This plant belongs to the kingdom Plantae and the phylum Streptophyta, falling under the class Equisetopsida and subclass Magnoliidae. Within the order Fabales, it is classified under the family Fabaceae and the genus Acacia. As a member of the genus Acacia, Acacia mearnsii is specifically recognized for its medicinal and industrial properties.

Sources: The World Checklist of Vascular Plants (WCVP)

Distribution

This plant exhibits a widespread geographical distribution across several key regions in the Mediterranean basin. In Southwestern Europe, it can be found inhabiting the territories of Portugal and Spain. Its presence also extends to the island of Corse within the same European sub-region. Moving toward Southeastern Europe, the species is documented growing in Italy. Finally, its range reaches into Northern Africa, specifically within the country of Algeria.

Sources: The World Checklist of Vascular Plants (WCVP)

Botanical Identification

Ecology

The ecology of Acacia mearnsii is characterized by its ability to thrive across a broad altitudinal gradient, ranging from low-lying areas to significant elevations. It is primarily found in lowland habitats, though it demonstrates remarkable adaptability to varying topographical settings. Its distribution spans an elevational range starting from as low as 70 m AMSL and extending up to a maximum of 1700 m AMSL, allowing it to inhabit diverse ecological niches within these vertical limits.

Elevational range max:

1700 m AMSL

Elevational range min:

70 m AMSL

Habitat :

Lowland

Life history

The life history of Acacia mearnsii is characterized by its status as a perennial species, allowing it to persist in its environment over many years through multiple growing seasons. As a phanerophyte, the plant maintains its photosynthetic organs on elevated branches above the ground level, a life form that facilitates its structural dominance in various habitats. It exhibits evergreen deciduousness, meaning it retains its foliage throughout the year rather than shedding it seasonally, ensuring continuous photosynthetic activity. This combination of a long-lived perennial lifecycle and a phanerophyte growth habit enables the species to establish stable, woody structures that support its long-term survival and reproductive success.

Deciduousness :

evergreen

Life form :

phanerophyte

Lifecycle :

perennial

Morphology

The morphology of Acacia mearnsii is characterized by a woody growth form that primarily manifests as a tree, though it can also exhibit a shrub-like habit. As a terrestrial and independent species, it does not function as an epiphyte or a parasite, nor does it possess aquatic or semiaquatic adaptations. The plant is a self-supporting organism rather than a climber, liana, or vine. In terms of stature, its height is highly variable, ranging from a minimum of 2.5 m to a maximum of 50 m, with an average height of approximately 15 m.

Aquatic :

terrestrial

Climber :

self-supporting

Epiphyte :

terrestrial

Growth form :

tree

Growth form :

shrub

Parasite :

independent

Plant height max:

50 m

Plant height mean:

15 m

Plant height min:

2.5 m

Woodiness :

woody

Physiology

The physiology of Acacia mearnsii is characterized by a specialized photosynthetic mechanism and highly adapted foliar structures. The plant utilizes the C3 photosynthetic pathway to convert light energy into chemical energy. Its leaves are morphologically distinct, featuring a narrow, elongated structure with a leaf length ranging from a minimum of 0.15 cm to a maximum of 2.5 cm, and a corresponding leaf width that varies between 0.05 cm and 0.08 cm. Furthermore, Acacia mearnsii plays a critical role in nutrient cycling within its ecosystem through its ability to function as a nitrogen fixer, facilitating the conversion of atmospheric nitrogen into forms usable by plants.

Leaf length max:

2.5 cm

Leaf length min:

0.15 cm

Leaf width max:

0.08 cm

Leaf width min:

0.05 cm

Nitrogen fixer :

yes

Photosynthetic pathway :

C3

Reproduction

The reproduction of Acacia mearnsii is characterized by a biotic pollination syndrome, primarily relying on insects and specifically bees to facilitate the transfer of pollen. The flowering period is quite extensive, typically beginning in April and continuing through August, though it can be variable throughout the year. This species is capable of self-fertilization, and it does not exhibit any forms of asexual reproduction. Following successful pollination, the plant develops fruit in the form of a pod. These pods are dehiscent, meaning they split open at maturity to release the seeds. The fruit dimensions vary, with a mean length of 6 cm (ranging from 7.5 cm to a maximum of 10 cm) and a mean width of 0.5 cm (ranging from 0.6 cm to a maximum of 0.8 cm). The seeds produced are small, with a mean mass of approximately 0.013245 g (ranging from 0.01038 g to 0.0165 g) and a consistent mean volume of 13 mm³. Individual seeds typically measure between 4 mm and 7 mm in length and 3 mm to 6 mm in width. Dispersal is classified as unspecialized, suggesting that the plant relies on general environmental or biological factors rather than a highly specific dispersal mechanism to spread its progeny.

Dehiscence :

dehiscent

Dispersal syndrome :

unspecialized

Flowering time :

Apr

Flowering time :

Aug

Fruit length max:

10 cm

Fruit length mean:

6 cm

Fruit length min:

7.5 cm

Fruit type :

pod

Fruit width max:

0.8 cm

Fruit width mean:

0.5 cm

Fruit width min:

0.6 cm

Pollination syndrome :

insect

Pollination syndrome :

bee

Pollination syndrome :

biotic

Reproduction asexual :

absent

Seed length max:

7 mm

Seed length min:

4 mm

Seed mass max:

0.0165 g

Seed mass mean:

0.013245 g

Seed mass min:

0.01038 g

Seed volume max:

13 mm³

Seed width max:

6 mm

Seed width min:

3 mm

Self fertilization :

present

Sources: Global Inventory of Floras and Traits (GIFT)

Plant Parts

Acacia mearnsii has 1 reported plant parts identified across 1 scientific publications and several other databases that are studied for medicinal purposes. The most consistently reported plant part include stem.

Stem

1. Molecules (Basel, Switzerland)

Chemicals

Acacia mearnsii has 2 reported phytochemicals identified across 1 scientific publications and several other databases. The most consistently reported chemicals include Flavonoids, Terpenoids.

Flavonoids

1. BMC complementary and alternative medicine

Terpenoids

1. BMC complementary and alternative medicine

Conditions

Acacia mearnsii has 1 reported investigations on conditions identified across 1 scientific publications and several other databases. The most consistently reported conditions include shigellosis.

Shigellosis

1. Molecules (Basel, Switzerland)

Preparations

Acacia mearnsii has 3 reported preparations identified across 1 scientific publications and several other databases. The most consistently reported preparations include crude extract, crude methanolic extract of the stem bark, methanolic extract.

Crude extract

1. International journal of molecular sciences

Crude methanolic extract of the stem bark

1. Molecules (Basel, Switzerland)

Methanolic extract

1. International journal of molecular sciences