Anacampseros septentrionalis Bruyns, 2021

Bruyns, Peter V. & Klak, Cornelia, 2021, A new species of Anacampseros (Anacampserotaceae) from northern Namibia, Phytotaxa 524 (1), pp. 67-70 : 67-68

Anacampseros septentrionalis Bruyns spec. nov.

Type:— NAMIBIA, near Ogams (1812CB), ± 350 m, 25 December 1999, Bruyns 8061 (holotype WIND!) .

Diagnosis:— Anacampseros septentrionalis differs from A. dinteri Schinz (1901: 873) by the longer scales in the axils of the leaves (5–6 mm vs. 3–5 mm), the presence of some hairs in the leaf-axils (absent in A. dinteri ) and by its thicker branches (6–8 mm vs. 4 mm).

Description ( Fig. 1 ):—Dwarf succulent with small turnip-like rootstock 5–10 × 3–5 mm, with 1–5 branches from apex. Branches 10–30 × 6–8 mm, white, ascending when moist to spreading close to ground when dry. Leaves elliptical, ± 1.5 × 2.5 mm, entirely covered by scales, green, with fine crinkled hairs around bases below and around flanks. Scales ovatelanceolate, 5–6 × 2.5–3.0 mm, acute, convex outside, translucent-white, ascending with slightly spreading tips. Flowers solitary, terminating branches on short pedicel 5–6 mm long, ± 10 mm diam. Capsule ± 3 × 3 mm, slightly exserted from among scales. Seeds ± 0.5 mm long, swollen and beaked, with fine white papillae over most of surface.

Distribution and ecology ( Fig. 2 ):—This small succulent occurs near the water-hole at Ogams, SW of Orupembe. This lies along the eastern boundary of the so-called Skeleton Coast in the northern part of the Namib Desert in Namibia. Here it was found in patches of white quartzitic gravel between low and somewhat crumbly granitic outcrops, together with Lithops ruschiorum ( Dinter & Schwantes 1925: 21) Brown (1926: 194) and another species of Anacampseros sect. Avonia that may belong to A. albissima ( Marloth 1912: 238) , which has also been found to occur further north along the northern bank of the Cunene River in Angola (Bruyns 10699, K, NBG, E). The area where A. septentrionalis occurs is surprisingly rich in succulents. Apart from these two species of Anacampseros sect. Avonia , there were the five stapeliads Ceropegia currorii ( Hooker 1844: t. 605–606) Bruyns in Bruyns et al. (2017: 420) ssp. currorii , C. oculatoides Bruyns in Bruyns et al. (2017: 424), C. marlothii ( Brown 1909: 894) Bruyns in Bruyns et al. (2017: 421), C. tirasmontana ( Plowes 1993: 58) Bruyns in Bruyns et al. (2017: 421), and C. rangeana (Dinter & Berger in Berger & Dinter 1914: 591) Bruyns in Bruyns et al. (2017: 427), as well as Adenia pechuellii ( Engler 1891: 383) Harms in Engler & Prantl (1897: 255) Cynanchum viminale (Linnaeus 1753: 452) Bassi ex Linneaus (1771: 392) , Hereroa puttkameriana (Dinter & Berger in Berger & Dinter 1914: 586) Dinter & Schwantes (1927: 24), Monsonia mossamedense Welwitsch ex Oliver (1868: 290) , as well as Euphorbia damarana Leach (1975: 500) , E. gariepina Boissier (1860: 28) , E. giessii Leach (1982: 27) and E. lignosa Marloth (1909: 316) . This wide variety of succulents suggests that, even if the area is hyper-arid, with a rainfall of not more than 50 mm annually, this low rainfall is fairly reliable and may be supplemented regularly by moisture from fog moving inland off the sea.

Plants of this new species were initially taken to represent A. dinteri Schinz (1901: 873) . However, as pointed out to PVB first by Coleen Mannheimer, it does not fit the description of A. dinteri as presented in Gerbaulet (1992). In particular, in A. dinteri there are no hairs in the axils of the leaves, the axillary scales are broadly ovate ( Gerbaulet 1992: Abb. 2e i) and measure 3–5 × 3 mm ( Rowley 2002), often with a dark midrib towards their apices (scales 5–6 × 2.5–3.0 mm and without darker midrib in A. septentrionalis ). The branches in A. dinteri are 4 mm thick ( Rowley 2002), while they are 6–8 mm thick in A. septentrionalis .

Figures

FIGURE 1. Left: Fruiting plant of Anacampseros septentrionalis, 45 mm tall, Bruyns 8061. Right: detail of structures around leaf:A, leaf (l) and axillary scale (as) from rear (scale 2 mm, as for B and C); B, leaf and axillary scale from side; C, leaf and base of axillary scale from rear showing hairs (drawn from Bruyns 8061).

FIGURE 2. Distribution of Anacampseros septentrionalis. The single known locality is indicated by a triangle.