Aloe rupestris Baker, 1896

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 rupestris Baker

Common names.

Bottle-brush aloe (English); borselaalwyn, kraalaalwyn (Afrikaans); inkhalane, umhlabanhlazi, uphondonde (Zulu).

Description.

Solitary, arborescent plant. Stem usually unbranched, up to 6-8 m high, erect, with persistent dried leaves in upper third only. Leaves densely rosulate, erectly spreading to recurved, dull to slightly glossy deep green, without spots, texture smooth, lanceolate-attenuate, 30-70 cm long, 7-10 cm wide; margin deep pink to pale red, with stout, pungent, reddish-brown, deltoid teeth, 4-6 mm long, 8-12 mm apart; exudate honey-coloured. Inflorescence 1.0-1.3 m high, erect, 6- to 9-branched from above middle, lower branches rebranched. Racemes cylindrical, very slightly acuminate, somewhat truncate, 20-25 cm long, 7 cm wide, very dense. Floral bracts ± 1 mm long, 2 mm wide. Pedicels 1-2 mm long. Flowers: perianth orange-yellow in bud, green striped in upper half, lemon-yellow in lower third and orange-yellow to brownish-yellow upwards when mature, 15-20 mm long, 4 mm across ovary, widening slightly towards middle, narrowing at mouth, cylindrical, slightly ventricose; outer segments free for 12 mm; stamens exserted 7-15 mm; style exserted 7-20 mm.

Flowering time.

August-September.

Habitat.

Zululand thornveld, coastal plain on sandy soils, sometimes dense bush, usually on rocky outcrops. Areas with warm, completely frost-free winters. Usually found in groups amongst trees.

Diagnostic characters.

Aloe rupestris differs from the other tall often single-stemmed aloes in KwaZulu-Natal ( Aloe candelabrum , Aloe marlothii , Aloe pluridens , Aloe spectabilis and Aloe thraskii ) with branched inflorescences, by having wide (30-70 × 7-10 cm), erectly spreading to recurved leaves that lack surface prickles and have pungent, reddish-brown marginal teeth. The inflorescence is 6- to 9-branched and rebranched with up to 20 erect, very dense, cylindrical, very slightly acuminate and somewhat truncate racemes of 20-25 cm long. Flowers are almost sessile, lemon-yellow to brownish-yellow and 15-20 mm long. The long-exserted deep orange to dark red stamens and style emerge from the flowers straight (not at an angle as in Aloe thraskii ).

Conservation status.

Least Concern ( Raimondo et al. 2009).

Distribution.

Central to northern KwaZulu-Natal in South Africa, eastern Eswatini and southern Mozambique (Fig. 37 ).

Figures

Figure 37. Aloe rupestris. Photo: G. Nichols.