Aloe braamvanwykii Gideon F. Sm. & Figueiredo

Smith, Gideon F., Figueiredo, Estrela, Klopper, Ronell R. & Crouch, Neil R., 2012, Summer-flowering species of maculate Aloe L. (Asphodelaceae: Alooideae) in the Aloe zebrina-complex from South Africa: reinstatement of four names, and description of A. braamvanwykii Gideon F. Sm. & Figueiredo, Bradleya 30, pp. 155-166 : 162-166

Aloe braamvanwykii Gideon F. Sm. & Figueiredo spec. nov.

Type: South Africa: North-West Province, on the farm Leeuwfontein 185, near Baskop alongside the tarred Leeufontein road, about 4 km from Wolmaransstad , 5 January 2012, Abrie Steyn, Gideon F. Smith & Estrela Figueiredo 1 ( PRE, holo.)

Small to medium-sized, herbaceous, slowgrowing, succulent, perennial, maculate aloe, total height excluding inflorescence 0.17–0.28 m, usually clumped, 5–70 heads, sometimes solitary, a single head up to (17–) 22 cm in diameter. Roots cylindrical, 5 mm in diameter. Stems absent or, if rarely present, very short. Leaves few, 12–15, rosulate, rigidly spreading to erect, persistent when dry, dull mid-green, upper surface slightly concave, hardly canaliculate, with numerous scattered white spots throughout, spots arranged in irregular transverse bands; lower surface convex, white spots more distinctly arranged in transverse bands, sometimes confluent yielding milky green surface, texture smooth, linear-attenuate, tapering to apex, 17–26 cm long, 3.5–5.5 cm broad at base, basally sheathing; margins very thin, brown, with triangular marginal teeth, green with light brown tips, ± 4 mm long, same length throughout, evenly spaced at 10–13 mm apart; exudate pale yellowish, drying purple. Inflorescence 1–3, successively, 0.65–0.75 m tall, far exceeding the height of rosette, central raceme longest, 5–7- branched from above middle, branches arcuateerect. Peduncle 270–420 mm long, 8–14 mm broad at base, basally plano-convex, cylindrical above, light greenish brown with a white, powdery bloom; not sterile bracteate; bracts subtending racemes narrowly triangular, 15–65 mm long, 6– 8 mm broad at the base, straw-coloured to light brown, papery, rarely fleshy, many nerved. Racemes cylindrical, 14–17 cm long, 3–5 cm wide; buds erect to suberect, flowers horizontal to drooping when mature. Floral bracts narrowly triangular, long attenuate, amplexicaul around pedicel, 5–9 mm long, 4–5 mm wide, straw-coloured, papery, 3–4 nerved. Pedicels 10–12 mm long, pinkish brown. Flowers: actinomorphic to slightly zygomorphic, unscented, nectariferous; perianth greenish tipped in buds, somewhat bicoloured when mature, light pink to mainly orange-red to bright red with whitish to yellowish longitudinal stripes, tip extremity purplish-brown or whitish, lightly pruinose, 20–25 mm long, flattened at base, ± 6 mm across ovary, distinctly narrowed above ovary to ± 3 mm to form globose basal swelling, enlarging to 6–7 mm towards throat and wide open mouth, tubular-cymbiform; outer segments larger than inner segments, lorate, free for ± 7 mm, free portion centrally pinkish red, borders white or light yellowish, acute, segment margins straight, tips slightly recurved; inner segments narrower than outer, with white or yellowish border and more obtuse apex, free for upper 2/3 of their length; stamens with cylindrically threadlike to very slightly flattened, light yellow filaments, 25–28 mm long, all 6 of ± equal length, exserted for 2–5 mm; anthers small, 1–2 mm long, dark brown, versatile; ovary 5–6 mm long, 3 mm in diameter, light green; style as long as or slightly longer than stamens, minutely capitate, with small stigma, exserted 1–2 mm. Fruit an erect, bright green, cylindrical, trilocular capsule, 17–22 mm long, 9–11 mm in diameter, apically truncate, dry remains of tepals shed from around fruit early on, dehiscing loculicidally, chartaceous when dry, apically valves sigmoidally curved outwards. Seeds dark greyish brown, angled, laterally compressed, 2.5–3.0 mm long, with up to 1 mm wide off-white wing stretching around periphery of seed. Chromosome number unknown. Floaeering time: December to February.

Diagnostic characters: This species is geographically isolated from other members of the A. zebrina -complex. Hitherto its existence has not been reflected by range maps for the complex as a whole, nor for any of the constituent species. It is probably most closely related to A. transvaalensis. Plants are long-lived and typically form dense clumps of up to 70 heads (Figures 6 & 9). Not only are its flowers the smallest (20–25 mm long) among South African members of the A. zebrina - complex, but they are also characteristic in being an unusual intense red (Figure 10). Also diagnostic are the general small stature of the plants and shorter inflorescences (0.65–0.75 m). An outstanding feature is its concentrated and relatively early (December to February) flowering period. Despite being subjected to probably the coldest winter temperatures, this species is the earliest of the local members of the complex to flower. Plants are consistently in bloom on Christmas Day (25 December), but flowering is brief and does usually not extend beyond the end of February.

Distribution: A. braamvanaeykii is only known from the Wolmaransstad, Schweizer-Reneke, Delareyville and Stella area, North-West, South Africa. The species has a very restricted distribution range with all known localities less than 50–100 km apart. Most of the natural vegetation surrounding the known range of the species has been destroyed for cultivation. However, the reasons for the species’ restricted distribution are not obvious. It is absent from fairly extensive areas of seemingly similar natural habitat (see below) towards Klerksdorp and Leeudoringstad.

Habitat: Plants are associated with relict stands of Klerksdorp Thornveld ( Mucina & Rutherford, 2006), a vegetation type characterized by unevenly scattered Acacia karroo -dominated tree stands in a grassland matrix. Plants mainly grow in full sun in open grassy areas among woody vegetation. Other commonly associated trees and shrubs include Acacia hebeclada subsp. hebeclada , Acacia robusta subsp. robusta , Asparagus laricinus , Diospyros lycioides subsp. lycioides , Ehretia alba, Greaeia flava, Searsia ciliata and Tarchonanthus camphoratus . Prominent grasses include Anthophora pubescens , Cymbopogon pospischilii , Digitaria eriantha , Eragrostis superba and Themeda triandra . Plants are typically associated with Lippia scaberrima , a highly aromatic perennial forb. Aloe braamvanaeykii prefers red sandy loam (often with small stone aggregates) derived from rocks of the Ventersdorp Supergroup ( Johnson et al., 2006), but occasionally can also be found on more clay-rich soils. Average annual rainfall is about 375 mm and falls mainly in summer. Winter nights are cold and subzero temperatures with frost are common.

Eponymy: Aloe braamvanaeykii is named after Prof. Braam van Wyk, from the University of Pretoria, who called our attention to this plant. If the epithet ‘ braamii ’ (excluding his surname therefore) was chosen, it could be confused with A. broomii Schönland , especially if written by hand. Moreover, several contemporary South African botanists go by the surname ‘Van Wyk’, which influenced our decision to unambiguously call the species A. braamvanaeykii. Braam co-authored the book on aloes in southern Africa ( Smith & Van Wyk, 2008) with one of us (GFS).

Further specimens: South Africa, Northwest. –2624: About 12 km north of Stella , on road to Papiesvlakte , (–BD), 3 March 1998, L. Smook 10103 ( PRE) . 2625: Baberspan Nature Reserve , (–DA), 12 March 1973, N. Zambatis 75 ( PRE) . 2725: Schweizer-Reneke district, (–AB), 16 February 1959, E. Werdermann & H.D. Oberdieck 2242 ( PRE) .