Acacia verticillata (L'Hér.) Willd.

  • Authority

    Isley, Duane. 1973. Leguminosae of the United States: I. Subfamily. Mimosoideae. Mem. New York Bot. Gard. 25 (1): 1-152.

  • Family

    Mimosaceae

  • Scientific Name

    Acacia verticillata (L'Hér.) Willd.

  • Description

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    Species Description - Straggly, usually densely branched, prickly, closely leafy shrub, 2-3 (-5) m. Young twigs greenish, glabrate to infrequently villosulous. Leaves simple, verticillate or subverticillate, 4-7 in a whorl (simulating spruce needles), linear, .7-1.4(-2) cm long, .7-1 (-2) mm wide, rigid, spinulose-pointed, with a single raised midnerve or weaker subsidiary nerves. Branches brightly yellow-floriferous in season; flowers in axillary, pedunculate spikes, 1-3 with leaf clusters, 1-2.5 cm long, ca 4 mm diam. Legume linear, straight to curved, laterally compressed but turgid and torulose, 2.5-6 cm long, 2-3 mm wide. Funiculus abruptly plicate, white.

  • Discussion

    CN 2n = 26 (Tjio, 1948). This species is available in the United States from several commercial sources (Mattoon, 1958; Mathias & McClintock, 1963), and is treated by Enari (1962). There is abundant material in herbaria, mostly easily recognized on basis of its whorled, narrow, 1-nerved leaves and glabrate twigs. But I am uncertain of its delimitation from A. oxycedrus which is pubescent, with 3-nerved leaves. Polymorphism in A. verticillata in Australia is acknowledged by Bentham (1864) through characterization of several varieties, and in the United States by Jones who refers to four different forms of the species on the University of California campus at Berkeley. Australian A. verticillata was described by Bentham as “pubescent or rarely glabrous,” but by several recent authors as glabrous. U.S. specimens are various as to shape of the spikes, leaflet proportions, strength of subsidiary veins, and presence or absence of pubescence. Pubescence, broad leaflets, and development of subsidary nerves are correlated, hence a bridge to A. oxycedrus. And, some material with the aspect and characteristic pubescence of A. oxycedrus has 1-nerved or weakly 3-nerved leaves. Australian material of A. verticillata and relatives seen is not sufficient to allow critical interpretation. Nevertheless the discontinuity between Australian A. verticillata and A. oxycedrus seems evident. Perhaps some horticultural material represents hybrids between the two species.

  • Distribution

    Urban California. Cultivated ornamental and slightly established. Sept.-April. Native of Australia.

    Australia Oceania|