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black wattle

Australian blackwood, blackwood, blackwood acacia

Habit Shrubs or small trees, erect, to 10 m. Trees, erect, to 30 m, usually spreading by root suckers.
Twigs

dark purplish brown to black, slightly flexuous, ridged, puberulent.

reddish brown, not flexuous, slightly ridged, glabrous.

Leaves

compound, 50–140 mm;

petiole 5–30 mm, puberulent, gland present, below proximalmost pinna pair, 0.7–1.5 mm diam., puberulent;

rachis glands scattered, with some between pinna pairs (at pinna pair nodes and internodes);

pinnae 7–31 pairs, 15–70 mm, 3–7 mm between pinna pairs;

leaflets 20–70 pairs per pinna, blades linear, 1.5–3.5 × 0.5–0.8 mm, base cuneate, apex obtuse, not apiculate, surfaces puberulent.

phyllodic, juvenile compound leaves often persisting on young plants;

phyllode flat, straight to slightly falcate, usually narrowly elliptic, rarely oblanceolate, 40–140 × 6–25 mm, venation parallel, with 3–5 prominent veins, minor veins prominently reticulate, apex narrowly obtuse to acute, apiculate, surfaces glabrous;

gland 0 (or 1), 0–5 mm distal to pulvinus when present;

pulvinus 2–5 mm.

Inflorescences

globose heads, densely flowered, 5–9 mm diam., in axillary pseudoracemes of 20–35 heads or terminal pseudopanicles of 1–10 pseudoracemes.

globose heads, densely flowered, 6–9 mm diam., in solitary pseudoracemes of 2–8 heads in leaf axils.

Peduncles

4–9 mm.

4–11 mm.

Flowers

5-merous, pale yellow to cream;

calyx 0.6–1.1 mm;

corolla 1.4–2 mm;

filaments 3.5–4.5 mm;

ovary glabrous.

5-merous, pale yellow;

calyx 0.9–1.3 mm;

corolla 1.5–2 mm;

filaments 2.5–3.5 mm;

ovary pubescent.

Legumes

flattened, linear, 30–140 × 4–8 mm, slightly constricted between seeds.

elliptic in cross section, linear, 50–150 × 4–8 mm, not constricted between seeds.

Seeds

aril light yellow, obovate, 1–2 mm, forming cap on seed.

aril yellow to pink to deep red, encircling seed in irregular double fold.

2n

= 26.

= 26.

Acacia mearnsii

Acacia melanoxylon

Phenology Flowering spring, early summer. Flowering fall, spring.
Habitat Disturbed areas. Disturbed areas.
Elevation 0–400 m. [0–1300 ft.] 30–300 m. [100–1000 ft.]
Distribution
from FNA
CA; se Australia [Introduced in North America]
[BONAP county map]
from FNA
CA; se, e Australia [Introduced in North America; introduced also in s South America]
[WildflowerSearch map]
[BONAP county map]
Discussion

Acacia mearnsii is known from Los Angeles, Orange, Riverside, San Diego, and Santa Barbara counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Acacia melanoxylon is known from Alameda, Contra Costa, Los Angeles, Marin, Mendocino, Monterey, San Diego, San Francisco, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Parent taxa Fabaceae > subfam. Caesalpinioideae (Mimosoid clade) > Acacia Fabaceae > subfam. Caesalpinioideae (Mimosoid clade) > Acacia
Sibling taxa
A. auriculiformis, A. baileyana, A. cultriformis, A. cyclops, A. dealbata, A. decurrens, A. longifolia, A. melanoxylon, A. paradoxa, A. pycnantha, A. redolens, A. retinodes, A. saligna, A. verticillata
A. auriculiformis, A. baileyana, A. cultriformis, A. cyclops, A. dealbata, A. decurrens, A. longifolia, A. mearnsii, A. paradoxa, A. pycnantha, A. redolens, A. retinodes, A. saligna, A. verticillata
Name authority De Wildeman: Pl. Bequaert. 3: 61. (1925) — (as mearnsi) R. Brown in W. Aiton and W. T. Aiton: Hortus Kew. 5: 462. (1813)
Source FNA vol. 11. FNA vol. 11.
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