Aloe thraskii Baker, 1880

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

NE Aloe thraskii Baker

Common names.

Dune aloe, strand aloe (English); strandaalwyn (Afrikaans); umhlaba (Zulu).

Description.

Solitary, arborescent plant, up to 3 m high. Stem simple, erect, 1-2 m high, can be up to 4 m, with persistent dried leaves. Leaves condensed rosulate, gracefully recurved, dull green to glaucous, without lines or spots, lower surface sometimes with a few spines in median line, lanceolate-attenuate, 160 cm long, 22 cm wide at base; margin very thin, narrow, reddish or brownish-red, with small deltoid reddish teeth, ± 2 mm long, 10-20 mm apart; exudate honey-coloured. Inflorescence 0.5-0.8 m high, erect, 4- to 8-branched. Racemes broadly cylindrical, slightly acuminate, somewhat truncate, up to 25 cm long, usually shorter, very dense. Floral bracts 9 mm long, 6 mm wide. Pedicels 1-2 mm long. Flowers: perianth greenish to orange in buds, lemon-yellow to pale orange when mature, greenish tipped, ± 25 mm long, ± 6 mm across ovary, enlarging towards throat, mouth constricted and upturned, cylindrical, slightly clavate; outer segments free for ± 17 mm; stamens exserted 15-20 mm; style exserted to 20 mm.

Flowering time.

June-July.

Habitat.

Beach dunes, in almost pure sand in low coastal vegetation or taller bush.

Diagnostic characters.

Aloe thraskii differs from the other tall, often single-stemmed aloes in KwaZulu-Natal ( Aloe candelabrum , Aloe marlothii , Aloe pluridens , Aloe rupestris and Aloe spectabilis ) with branched inflorescences, by its strictly coastal habitat and in having long ( ± 160 × 22 cm), strongly recurved, deeply channelled leaves with small reddish marginal teeth. The inflorescence is 4- to 8-branched with erect, very dense, broadly cylindrical, slightly acuminate and somewhat truncate racemes of up to 25 cm long. Flowers are lemon-yellow to pale orange and ± 25 mm long. The long-exserted yellowish-orange stamens and style emerge from the flower at an angle (not straight as in Aloe rupestris ).

Conservation status.

Near-threatened. Threats include habitat loss owing to urban expansion along the coast, as well as illegal collecting ( Raimondo et al. 2009).

Distribution.

Occurs in a narrow coastal strip from the far northern coast of the Eastern Cape into KwaZulu-Natal to just north of Durban, South Africa (Fig. 44 ).

Figures

Figure 44. Aloe thraskii. Photo: G. Nichols.