Aloidendron barberae (Dyer) Klopper & Gideon F.Sm.

Klopper, Ronell R., Crouch, Neil R., Smith, Gideon F. & van Wyk, Abraham E., 2020, A synoptic review of the aloes (Asphodelaceae, Alooideae) of KwaZulu-Natal, an ecologically diverse province in eastern South Africa, PhytoKeys 142, pp. 1-88 : 1

Aloidendron barberae (Dyer) Klopper & Gideon F.Sm.

Syn.

Aloe barberae Dyer.

Common names.

Tree aloe (English); boomaalwyn, mikaalwyn (Afrikaans); impondondo, indlabendlazi, inkalane unkulu, umgxwala (Zulu).

Description.

Arborescent plant, up to 18 m high. Stem 10-18 m high, profusely branched dichotomously and rebranched from about middle, erect, without persistent dried leaves. Leaves densely rosulate, recurved, dull green, without spots, ensiform, deeply channelled, 60-90 cm long, 7-9 cm wide at base; sheath with greenish-white marginal border; margin narrow, white, cartilaginous, with firm, horny, brownish tipped, dull white, deltoid teeth, 2-3 mm long, 10-25 mm apart. Inflorescences 0.4-0.6 m high, erect, dichotomously 3-branched. Racemes cylindrical, slightly acuminate, 20-30 cm long, dense. Floral bracts 8-10 mm long, ± 1 mm wide. Pedicels 7-10 mm long. Flowers: perianth rose to rose-pink, greenish tipped, 33-37 mm long, ± 9 mm across ovary, not narrowed above ovary, widening towards middle, narrowing somewhat towards upturned mouth, cylindrical-ventricose; outer segments free almost to base; stamens exserted to 15 mm; style exserted 15-20 mm.

Flowering time.

May-August.

Habitat.

Dense, tall bush and low forest, rocky slopes of wooded valleys.

Diagnostic characters.

Aloidendron barberae is one of only two large-growing tree aloes indigenous to KwaZulu-Natal. These two aloes both have dichotomously branched stems and branches that lack persistent dried leaves. Aloidendron barberae differs from Aloidendron tongaense in being much taller (up to 18 m) with more branches and having larger bright green leaves of 60-90 cm long (not dull green and 40-59 cm); their distribution ranges are also mutually exclusive. The inflorescence is also slightly taller at 0.4-0.6 m (not ± 0.35 m) and 3-branched from a single point (not up to 6-branched), with longer cylindrical racemes of 20-30 cm long (not capitate and 4-6 cm), bearing straight rose-pink flowers that are 33-37 mm long (not curved yellow flowers of 47-50 mm) with stamens exserted to 15 mm at anthesis (not 3-5 mm).

Conservation status.

Least Concern ( Raimondo et al. 2009).

Distribution.

Occurs in scattered localities, often in inaccessible sites (with steep gradients), in a broad coastal zone from East London in the Eastern Cape, through KwaZulu-Natal and Mpumalanga, South Africa, also in Eswatini (Fig. 3 ).

Notes.

Aloidendron barberae is often cited as occurring in Mozambique, the latest of these being Van Jaarsveld and Judd (2015). However, an examination of available herbarium specimens at several South African and European herbaria has shown that specimens from Mozambique all represent A. tongaense ( Walker et al. 2019b). This is supported by Burrows et al. (2018) who only treat the latter species. However, considering that A. barberae is common on the South African side of the Lebombo range, it may well be present in nearby southern Mozambique, which borders on the foothills of the range. Further investigation is needed to confirm whether or not A. barberae is present in this botanically under-explored part of Mozambique.

Figures

Figure 3. Aloidendron barberae. Photo: G. W. Reynolds.