Aloe condyae Van Jaarsv. & P. Nel, 2012

van Jaarsveld, Ernst J., 2012, Aloe condyae, a new cliff-dwelling aloe from Mpumalanga, Republic of South Africa, Bradleya 30, pp. 167-172 : 169-171

Aloe condyae Van Jaarsv. & P. Nel , spec. nov.,

A.nubigenae similis, sed ab illa foliis rosulate ascendentibus, 200–300 (–350) × 10–15 (–20) mm metientibus, basi fuscobrunneis et dense maculatis, marginibus distincte denticulatis, floribus (12–30) in racemo dense capitato aggregatis, perianthio 30 mm longo differt.

Type: South Africa, Mpumalanga, 2531 (Barberton): Boekaalwynkloof, behind Angle Station, Drakensberg , sheer east-facing quartzitic, sandstone cliffs, (–CC), Van Jaarsveld & Nel 24252 ( PRE, holo.) .

Perennial succulent, solitary or with subterranean suckers, forming small groups up to 100 mm in diameter. Roots fleshy. Branches ascending to ascending-spreading about 15 mm in diameter. Leaves flaccid, rosulate, 8–14 per head, linear-lanceolate, 200–300 m (–250) × 10–15(–20) mm ascending spreading becoming somewhat recurved and occasionally pendent from rock faces, fleshy and channelled, especially during the dry season, smooth, green, dark brown at base and densely white-spotted; abaxial side flat to convex, adaxial side channelled; margin denticulate, white, cartilaginous; triangular teeth 0.7 × 0.4 mm, 1–3 mm apart; apex acuminate. Inflorescence simple, decumbent, 220–290 mm tall; peduncle 170–230 mm long, 5–7 mm broad and slightly flattened at base, biconvex, with 5–6 sterile bracts, 10–20 × 9 mm long and clasping; raceme short, capitate 40–60 mm long, flowers densely arranged (12–30-flowered); floral bracts scarious, deltoid, acuminate, 15 × 5 mm; pedicels 20–25 mm long, ascending, orange. Perianth oblong, pendent, 30 mm long, orange-red; apices obtuse to subacute; tube cylindrical-trigonous; segments free to base, outer three, 30 × 3.5 mm, linear-lanceolate, canaliculate; inner three 30 × 6 mm. Stamens yellowish, 27–29 mm long. Ovary oblong, 5 × 1.5 mm, grooved, brownish green; style 27 mm long. ( Figures 1 –5, 7–8.)

Flowering time: mainly in summer (December to February).

Distribution, habitat and ecology

Aloe condyae is known only from the upper vertical, quartzitic, sandstone cliffs (south- and southwest-facing) at Boekaalwynkloof near Angle Station, which is part of the northern Drakensberg ( Figure 6 ). It grows at an altitude of 1,700 – 1,800 m, frequently covered in cloud. Plants grow solitary or as small clusters, scattered in rock crevices among lichens and moss. Rainfall is high, from 1,500 –1,750 mm per annum, and is experienced mainly in summer. Vegetation of the region includes Barberton Montane Grassland on exposed slopes and Northern Mistbelt Forest in the protected kloofs ( Mucina & Rutherford, 2006). The new species grows in the Barberton centre of plant endemism ( Van Wyk & Smith, 2001) and was found in association with other temperate, high-altitude plants such as Aloe arborescens , Aloe suprafoliata , Elaphoglossum sp., Begonia sutherlandii , Crassula albiflora , C. natalensis , C. sarcocaulis , C. swaziensis , Cyanotis speciosus , Morella pilulifera , Ornithogalum juncifolium , Plectranthus purpuratus subsp. montanus , Streptocarpus sp. and Thorncroftia thorncroftii . The conspicuous tubular flowers suggest pollination by resident sunbirds ( Nectarina spp.).

Discussion

There are more than 125 species of Aloe indigenous to South Africa and Namibia ( Glen & Smith, 2003). Aloe condyae is the seventeenth species of South Africa confined to cliffs (21%) and the fifth member of section Leptoaloe recorded as confined to sheer cliff faces in South Africa and Namibia. Apart from our new species these include A. challisii Van Jaarsv. & Van Wyk , A. nubigena Groenewald , A. thompsoniae Groenewald and A. soutpansbergensis I.Verd. , all of them confined to mineral poor sandstone soils, with soft, flaccid leaves bearing small or no ( Aloe nubigena ) marginal teeth (see Table 1 ) ( Craib, 2005; Van Jaarsveld & Van Wyk, 2006). A. nubigena , A. challisii and A. soutpansbergensis also have a pendent habit. Aloe condyae is at once distinguished from other cliff dwelling species in section Leptoaloe by its ascending rosettes with linear-lanceolate leaves 200–300 × 10–15(–20) mm, dark brownish and densely spotted at the base and of which the margin is distinctly denticulate, as well as its dense capitate inflorescence 220–290 mm long (with 12–30 flowers), the peduncle 4–7 mm in diameter at the base and its perianth 30 mm long. It is related to both A. nubigena , and A. thompsoniae . Aloe nubigena , which is confined to the escarpment mountain north of Graskop (Mpumalanga) usually has a drooping nature, distichous to subdistichous leaves, of which the margin is entire or rarely denticulate, and has a slightly shorter perianth of 25 mm long. Aloe thompsoniae is only known from the northern extreme of the Drakensberg Mountains near Tzaneen (Limpopo Province) and is at once distinguished by its smaller, densely proliferating rosettes.

A key is provided for the five species of cliff-dwelling members of Aloe section Leptoaloe (grass aloes) in South Africa.

Etymology

It is with pleasure we name this new cliff dwelling species after Gillian Condy, official artist of the South African National Botanical Diversity Institute since 1983 ( Arnold, 2001). Gillian has made a huge contribution to African Botanical art and is a winner of several art awards. She is a founder member of the Botanical Artists’ Association of South Africa (BAASA) and has a particular eye for the grass aloes, and her beautiful work can be seen in several publications such as The Flowering Plants of Africa (the serial publication showcasing South African botanical art that was founded in 1921), Grass aloes of the South African Veld ( Craib, 2005) and Geophytic Pelargoniums ( Craib, 2001).

Figures

Figure 1. A drawing of Aloe condyae in its natural habitat south of Barberton. Artist: Eric Judd.

Figure 6. The cliff face habitat of A. condyae at Boekaalwynkloof, south of Barberton. Figure 7. A close-up of the perianth of A. condyae. Figure 8. A. condyae in habitat near Angle Station, Mpumalanga.