Australian Tropical Rainforest Plants - Online edition

Acacia holosericea A.Cunn. ex G.Don


Shrub (woody or herbaceous, 1-6 m tall)
Click/tap on images to enlarge
Leaves and flowers. © Australian Plant Image Index (APII). Photographer: M. Fagg.
Fruit [not vouchered]. CC-BY J.L. Dowe
Scale bar 10mm. © CSIRO
1st leaf stage. © CSIRO
Cotyledon stage, epigeal germination. © CSIRO
10th leaf stage. © CSIRO
Family

Don, G. (1832) General History of Dichlamydeous Plants 2 : 407. Type: Port Keats, Cambridge Gulf, Oct. 1819, Cunningham; lecto: BM, K. Fide Pedley (1978).

Common name

Silky Wattle; Silver-leaved Wattle; Wattle, Silky; Wattle, Silver-leaved

Stem

Usually flowers and fruits as a shrub 1-4 m tall.

Leaves

Leaves phyllodineous, usually clothed in white appressed hairs which give the leaf a velvety texture and a grey-green appearance. Leaf blades about 6.5-17 x 1.7-4.8 cm. A gland usually visible on the margin at the leaf blade-petiole junction. Veins longitudinal and parallel, about 3 or 4 veins more prominent than the rest. Petiole somewhat swollen and transversely wrinkled but wrinkling often difficult to see because of the covering of pale hairs.

Flowers

Flowers yellow, spikes about 3-6 cm long, moderately dense, usually produced in pairs in the upper axils. Calyx sericeous or tomentose, about 0.5-0.7 mm long. Corolla sericeous or tomentose, about three times as long as the calyx.

Fruit

Pods tightly coiled, about 2.5-5 mm wide, usually with many pods tangled together. Seeds brown-black with the long axis parallel to that of the pod. Funicle yellow.

Seedlings

Cotyledons oblong, about 4-5 x 2-3 mm, apex obtuse, base sagittate or auriculate. First leaf pinnate, second leaf bipinnate. By the sixth or seventh leaf stage: leaves bipinnate, petiole broadly flattened. At the tenth leaf stage: leaves phyllodineous, narrowly elliptic, usually with two main veins running from the base to the apex or bipinnate with flattened petioles. Stipules triangular, about 1.5-2 mm long. All parts of the seedling usually clothed in fine white hairs. Seed germination time 9 to 14 days.

Distribution and Ecology

Endemic to Australia, occurs in WA, NT, CYP, NEQ, CEQ and southwards as far as coastal central Queensland and southern inland Queensland. Altitudinal range from near sea level to 900 m. Usually grows in open forest but sometimes found in monsoon forest and vine thickets.

Natural History & Notes

This species has been used as a fish poison.

Synonyms
Acacia holosericea var. typica Domin, Bibliotheca Botanica 89(4): 824(1928). Racosperma holosericeum (G.Don) Pedley, Austrobaileya 2(4): 349(1987). Acacia holosericea var. multispirea Domin, Bibliotheca Botanica 89(4): 824(1928), Type: Queensland, Chillagoe, Feb. 1910, Domin 5176; holo: PR. Acacia mangium var. holosericea (G.Don) C.T.White, Contributions from the Arnold Arboretum of Harvard University 4: 42(1933. Acacia holosericea var. neurocarpa (Hook.) Domin, Bibliotheca Botanica 89(4): 824(1928). Acacia holosericea var. glabrata Maiden, Proceedings of the Royal Society of Queensland 30: 48(1918), Type: Gilbert River (E.W. Bick 146), communicated by C.T. White. Iso: BRI.
RFK Code
3114
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