Rubus chrysocarpus Chamisso & Schlechtendal (1827: 17)

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 : 31-33

11. Rubus chrysocarpus Chamisso & Schlechtendal (1827: 17)

Homotypic synonym:— Rubus rigidus var. chrysocarpus (Cham. & Schltdl.) Harvey & Sonder (1862: 287) .

Type:— SOUTH AFRICA. Western Cape: ‘In promontorio bonae spei ad Hexrivier Januario 1819 legerunt Mund et Maire’, Mundt & Maire s.n. (the number 223 is written on the label by Schlechtendal) (holotype Bˍ10ˍ1146999 [http://herbarium.bgbm.org/object/ B101146999 ]) .

Note on type: —There is another specimen of the Schlechtendal collection in HAL ( SOUTH AFRICA. Western Cape: ‘Prom. Bon. Sp.’, s. dat., Mundt & Maire s.n., ‘135’, HAL 0098161). It is conserved under the name R. mundtii , but from comparison with the holotypes and the protologues it is clear, that it is R. chrysocarpus . Maybe it is an isotype of which the label is confused.

Mundt and Maire collected R. chrysocarpus in Hexrivier. A sample in P collected by Zeyher (P02579099) at the Modderdrift farm in Hexrivier (elevation 1500 ft, IV,b,6), 23 April 1827, is the same taxon. Some of the specimens that Ecklon and Zeyher (nr. 1708) distributed as R. chrysocarpus are also correctly identified, but the sample in NBG is R. leptodytus . Recent investigations in Hexrivier to find the species there were unsuccessful, which is no wonder because even the last square meter is cultivated for vineyards now. The characteristic species is, however, rather abundant in the Jonkershoek Valley near Stellenbosch, so that a description could be made from fresh and complete material.

Primocane ( Figs 9A–D ) erect to arching, diam. 5–11 mm, roundish, with dense very short yellowish grey stellate hairs and with very few (sub-)sessile to rather numerous stipitate glands; prickles 0–12 per 5 cm, unequal, largest ones from 2–4 mm broad base bluntly compressed with hooked tip, up to 4–7 mm long, hairy, sometimes with few glands; between big prickles 0–3 little conic pricklets per 5 cm; stipules 9–15 mm, linear(-lanceolate), greyish brown tomentose, with some subsessile or short stipitate glands. Leaves coriaceous, with undulate margin, 3-foliolate or pinnate 5-foliolate, often with additional leaves at first and sometimes second yoke, sometimes with tendency to be pinnate 7- foliolate by incision of central leaflet, adaxially ( Fig. 9E ) with only few hairs in furrows of main veins, abaxially ( Fig. 9F ) short white tomentose, with pronounced veins; serrature moderately fine, irregular, not or very shallow periodical, with obtuse teeth; petioles 3–7 cm long, densely short tomentose, with some (sub-)sessile or short stipitate glands, 4–10 curved or hooked prickles; central leaflet 42–58 mm long, ovate, elliptical or obovate with truncate or attenuate, or sometimes cordate base, acute or with short tip, width–length index 0.61–0.93, length of petiolule 20–41% of length of leaflet; petiolule of lateral leaves 3–10 mm. Flowering branch ( Fig. 9G ) obtuse angular or roundish, with very short yellowish grey stellate hairs, some sessile and few to rather numerous stipitate glands; prickles 1–4 per 5 cm from 2–3 mm broad base, subulate with hooked tip, up to 4–6 mm long. Leaves 3-foliolate, upper ones simple, adaxially with only few hairs in furrow of main veins, shiny, abaxially appressed white tomentose; central leaflet 62–69 mm, with rounded or sometimes attenuate base, ± elliptic, width–length index 0.57–0.80, length of petiolule 19–34% of length of leaflet. Inflorescence ( Fig. 9H ) with straight or somewhat flexuous axis, with 3–4 lateral branches in angle of leaves and narrow cylindrical tip, short tomentose, with some short stipitate glands, and few curved or hooked larger prickles; peduncles racemose, dense, divided from base, longest with 10–12 flowers, tomentose, with some to rather numerous short stipitate glands; pedicels ( Fig. 9I ) 2–8 mm, unarmed. Flowers: sepals loosely erect, 2–4 × 5–8 mm, gradually or rather abruptly attenuate into short or rather long tip, short grey tomentose and with subsessile glands; petals pink, rather large, longer than sepals; anthers glabrous; styles red, ovaries and receptacle glabrous. Ripe fruit ( Fig. 9J ) yellow to deep orange.

Ecology: —Riverbanks, humid mountain slopes.

Distribution: —Recently, only found in the Jonkershoek valley near Stellenbosch, Western Cape, South Africa.

Specimens:— SOUTH AFRICA. Western Cape: Stellenbosch, Jonkershoek reserve, along the left turn off along the river from the circular drive, beginning short after the dam, 24 February 2019, Beek 2019.39 ( L); Stellenbosch , Jonkershoek reserve , along the left turn off along the river from the circular drive, beginning short after the dam, 24 February 2019, Beek 2019.40 ( L); Jonkershoek, Eerste Rivier, 1000 ft, December 1965, O . Kerfoot 5501 ( NBG); Stellenbosch, Jonkershoek , Swartboskloof , langs en oor Kontoerpad , 20 August 1963, J. J . Bos 449 ( NBG); Bosboukloof, Jonkershoek , 2500 ft, May 1967, O . Kerfoot K5833 ( NBG); Baviaansrivier near Genadendal and Waterfall near Tulbagh, November /December, Ecklon & Zeyher 1708 ( HAL 147328 ) .

Notes: —Two forms of Rubus were found near Stellenbosch that are obviously related to R. chrysocarpus , but seem to be not identical to it. One is a little bramble on the northern slopes of the Jonkershoek valley with even more abundant and longer stipitate glands, pending inflorescences, and well developed shiny black fruits like those of European blackberries ( SOUTH AFRICA. Western Cape: Stellenbosch, Jonkershoek reserve, along the circular drive ± 1.5 after the bridge, at the left side, 13 November 2019, Beek 2019.87, L). Another group of plants has shiny orange fruits, but differs from R. chrysocarpus by (almost) flat, not undulate, leaves, longer hairs in the inflorescence, and larger sepals; the plants are stronger and higher. It was found along vineyards on several places in the Devon Valley region northwest of Stellenbosch:— SOUTH AFRICA. Western Cape: Stellenbosch, Devon Valley, Fransmanskraal Farm, 14 November 1978, C. Boucher 4092 (NBG); Stellenbosch, Waterkloof Farm, 25 February 1994, P. Nel & C. Boucher 0071 (NBG); Stellenbosch, December 1965, O. Kerfoot K.5501 (NBG); Stellenbosch, Devon Valley Road, soon after the Dog Box at the right side at the entrance of a vineyard, 16 January 2019, Beek 2019.1 (L); ibid., 31 October 2018, Beek 2018.122 (L).

Because these forms are both limited to a small area and the precise relation to R. chrysocarpus is unclear, they were not described. Maybe molecular research can give more clarity in the future.

East of the Buffelsjagrivier near Swellendam , plants were found that look like strong samples of R. chrysocarpus , but are (almost) glandless and have black fruits:— SOUTH AFRICA. Western Cape: Buffelsjagrivier , Alb. Müller, Zeyher 2450 b, October ( NBG); along the road from Swellendam to Suurbraak , 13 January 2020, Beek 2020.02 ( L) .

Figures

FIGURE 9. Rubus chrysocarpus. A. Habit. B. Primocane with leaves. C. Primocane. D. Primocane. E. Leaf, adaxially. F. Leaf, abaxially. G. Flowering branch. H. Inflorescence. I. Pedicels and flowers. J. Fruits. Photographs: A. van de Beek.