Flora of New Zealand Series

Perennial or monocarpic; stems trunk-like, 20- c. 70 cm high, 1-2-(5) cm diam., not branched or with few to many lateral branches towards base, with numerous narrow, brown, elongated lf scars. Rosettes terminal, usually 7-20 cm diam. on main shoots, smaller on lateral branches, flattened except in summer. Outer rosette lvs to 8-(11) × 3-(4) cm, 2-3 mm thick, oblanceolate to obovate or obovate-spathulate, green or occasionally purple, glabrous and ± flat on both surfaces; margins ciliate or ciliolate, mostly green, sometimes red towards the mucronate apex. Flowering shoots terminal, either the whole plant or the stem bearing the infl. dying after flowering; axis stout, tall and erect, usually finely covered with very short glandular hairs, very rarely glabrate, with leaflike bracts usually deciduous by peak flowering. Infl. a broadly ovoid-pyramidal panicle, rounded at the top, usually 10-18 × 6-13 cm; fls densely arranged, not obviously secund on branches. Calyx lobes 1.5-3 mm long, puberulent with very short glandular hairs, lanceolate, narrow- to broad-triangular. Petals (7)-8-11, 6-9 × 1.5-2.5 mm, linear or linear-oblong to ± lanceolate-ovate, usually golden, rarely medium yellow. Stamens ± golden, the inner whorl 5-8.5 mm long, the outer whorl usually slightly shorter. Carpels greenish yellow. Scales (0.5)-0.8-1.2 mm long, ± square to rectangular or cuneate, truncate, erose or emarginate at apex. Seeds c. 0.5 mm long, narrowly ellipsoid, longitudinally ridged.

N.: Rangitoto Id (Auckland), Wellington; S.: Nelson, Port Hills and E. side of Lyttelton Harbour (Banks Peninsula), Otago Peninsula.

Morocco 1959

Coastal slopes and cliffs, often on volcanic rock and in low scrub of other Crassulaceae or other spp., occasionally in sand and among rocks behind beaches.

FL Jul-Oct.

A. arboreum is an escape from cultivation which is only fully naturalised on the Port Hills and other parts of Banks Peninsula. It is the first Aeonium sp. to flower, often commencing in midwinter. Cultivated plants often have dark purple lvs, at least when young and when fully exposed, corresponding to cv. 'Atropurpureum', but such plants rarely grow wild.

A few plants seen on Banks Peninsula have ± glabrous infls with medium yellow (not golden) fls (e.g., CHR 243418, Church Bay, Banks Peninsula, Sykes, 13.10.1987), but are otherwise very similar to typical A. arboreum in the same population. Since A. haworthii, A. undulatum and many putative hybrids occur at the same site, it is possible that the specimen cited is also a hybrid. Surprisingly, hybrids of A. arboreum, probably the most widespread sp. in cultivation, do not seem to have been recorded.

Healy, A. J., Trans. Roy. Soc. N.Z. 87: 233 (1959), mostly correctly recorded this plant as A. arboreum although the collection he cited contains a lf of A. × velutinum. Given (1984) listed A. cf. ciliatum and noted that this plant may represent a hybrid between A. ciliatum (Willd.) Webb et Berth. and A. urbicum; his record is based on plants of A. arboreum.