Rubus leptodytus A.Beek, 2021

Beek, Abraham Van De, 2021, Rubi Capenses: a further contribution to the knowledge of the genus Rubus (Rosaceae) in South Africa, Phytotaxa 515 (1), pp. 1-71 : 29-31

10. Rubus leptodytus A.Beek sp. nov.

Type:— SOUTH AFRICA. Western Cape: Citrusdal, Karnemelksvlei , 20 November 2019, Beek 2019.93 (holotype L; isotype NBG). ( Figs 8A–C )

Diagnosis: —A taxon with characteristics that are different from both R. rigidus and R. ecklonii occurs in the more northern regions of the Western Cape, from Citrusdal to Oudtshoorn. It has, in contrast to R. ecklonii , many stipitate glands on the primocane and some in the inflorescences like R. rigidus , but the leaflets are much broader than in the latter, the serrature is shallower and the leaves have abaxially a very short tomentum ( leptodytus means ‘with thin clothes’). Because it is very characteristic and has a rather wide distribution it is described here as a new species.

Primocane ( Figs 8D–F ) suberect to high arching, when supported in shrubs up to more than 3 m high, sometimes finally tip rooting, diam. 5–10 mm, furrowed, densely very short stellate hairy, with numerous stipitate glands; prickles 4–17 per 5 cm, very unequal, with 1–3 mm broad base, compressed, curved or hooked, up to 3–5(–6) mm long; stipules linear 8–15 mm, short hairy, with stipitate glands. Leaves ( Fig. 8G ) 3-foliolate, rarely pedate 5-foliolate, or 2-jugate pinnate, adaxially glabrous, abaxially very short white tomentose, sometime becoming almost green; serrature fine to mediocre, obtuse, shallow, short obtuse periodical, with very short mucros; petiole 4–8 cm, very short tomentose, glandular, with 8–16 curved or hooked prickles; central leaflet of 3-foliolate or pedate leaves 47–75 mm, with cordate or rarely roundish base, suborbicular or almost quadrangular, gradually attenuate, acute or with broad short tip, or obtuse, usually lobate, width–length index 0.76–1.14, petiolule 20–43 mm; petiolule of basal leaves 5–20 mm; central leaflets of pinnate leaves 42–61 mm, with attenuate to cordate base, ovate, triangular, roundish or (elliptical-)obovate, acute or obtuse, width–length index 0.69–0.96, petiolule 10–22 mm. Flowering branch ( Fig. 8H ) furrowed, with dense very short stellate hairs and few to numerous stipitate glands; prickles 2–7 per 5 cm from 2–5 mm broad base (slightly) compressed, curved or hooked, up to 2–4 mm long. Leaves 3-foliolate, or upper ones sometimes simple, adaxially glabrous or rarely with some appressed hairs, abaxially appressed grey tomentose or basal ones green; serrature usually shallow, fine to mediocre, with very short mucros, very shallowly to rather pronouncedly periodical. Inflorescence ( Fig. 8I ) cylindrical-pyramidal, with straight or somewhat flexuous axis, with 1–7 axial branches with sharp angle, short tomentose, with some to many stipitate glands, few weak curved or declining pricklets; peduncles often divided from base, longest with 4–16 flowers, tomentose, with some short stipitate glands; pedicels ( Fig. 8J ) 2–14 mm. Flowers: sepals patent to erect, 2–4 × 6–8 mm, ovate, with short tip, short grey tomentose and with few subsessile and short stipitate glands; petals ( Fig. 8K ) pinkish red, orbicular or obovate, 4.5–6.0 × 6–8 mm; stamens deep purple red, shorter than or equalling styles; anthers and ovaries glabrous; styles deep purple red; receptacle with some hairs. Ripe fruit ( Fig. 8L ) pale yellow to brownish orange, not very juicy.

Ecology: —Humid places along ditches, in fields, hedges, roadsides.

Distribution: — Rubus leptodytus has a rather wide distribution in the Western Cape, South Africa; it is common south of Citrusdal near the Theerivier, and at several places around Algeria; more to the south near Tulbagh; further, in Oudtshoorn (Cango Valley), along the road to the Gamkaskloof, and near Caledon; specimens from Avontuur and Swellendam might also belong to it.

Specimens:— SOUTH AFRICA. Western Cape: Theerivier, Citrusdal, 7 September 1968, Hanekom 1183 (PRE); Citrusdal, south of Theerivier, 20 November 2019, Beek 2019.94 (L); Citrusdal, south of Theerivier, 20 November 2019, Beek 2019.95 (L); Algeria, along the road ± 10 km south of the Forest station, in shadow of rock, 20 November 2019, Beek 2019.96 (L); Algeria Forest Station, 16 November 1996, Van Rooyen, Steyn & de Villiers 207 (NBG); Tulbagh, Winterhoek road, 21 November 2019, Beek 2019.99 (L); Seweweekspoort, in Klein Swartberg near Ladismith, at the farm Aristata, Henderson 1109 (PRE); Oudtshoorn, Cango Valley, after the off road to the Swartbergpass just before the Grobbelaars River, east side of the road, 21 January 2020, Beek 2020.12 (L); Boomplaas, Cango Valley, 5 February 1975, Moffet 608 (NBG); Caledon, Riviersonderend Valley, near the farm Terra Bona, 18 February 1992, Henderson 1152 (PRE); Rivierzonder Einde, N. Ecksteen, November, Zeyher 2450 [?] (NBG, ‘ Rubus chrysocarpus’); Baviaansrivier near Gnadendal and Waterfall near Tulbagh, November/December, Ecklon & Zeyher 1708 (NBG, ‘ Rubus chrysocarpus’, it is not clear if this specimen is from Gnadendal or from Tulbagh).

Figures

FIGURE 8. Rubus leptodytus. A. Holotype, primocane. B. Holotype, primocane. C. Holotype, inflorescence. D. Plant of the type, habit. E. Primocane. F. Primocane. G. Leaves. H. Flowering branch. I. Inflorescence. J. Pedicels. K. Flowers. L. Fruits. Photographs: A. van de Beek.