Rubus macropetalus Dougl. ex Hooker (1832: 178)

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 : 46-47

21. Rubus macropetalus Dougl. ex Hooker (1832: 178) .

Lectotype:—to be designated

Syntypes:—‘ R. longipetalus D.D.’ (K000762064) [http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000762064]); ‘ Rubus myriacanthus D.D. Com Stapf, O., Sprague, T.A., Rolge, R.A., Clarke, C.B., Dawe, M.T. & Wright, C.H. (1906) Plantae novae Daweanae in Uganda Lectae. Journal of the Linnean Society 37: 495–532. https://www.biodiversitylibrary.org/item/8402#page/546/ mode/1upmon on the banks of streams near the ocean N.W. Amer.’ Douglas s.n. (K000762063 [https://apps.kew.org/herbcat/ getImage.do?imageBarcode=K000762063]).

Primocane ( Figs 18A–B ) high arching, roundish to angular, diam. 3–4 mm, with rather numerous long patent hairs, and 10–100 unequal partially long stipitate glands; prickles 2–10 per 5 cm, unequal, most of them very short and acicular, some fine but compressed and little curved, up to 2 mm long, yellow; stipules 7–9 mm, linear-lanceolate, green, hairy. Leaves ( Fig. 18C ) digitate 3- to 5-foliolate, adaxially with some appressed hairs, becoming glabrous, abaxially green, thinly soft pubescent; serrature deep, periodical, with straight teeth; petiole 10–12 cm, with patent hairs and 15–30 unequal, up to 2 mm long, acicular or somewhat compressed declining or slightly curved prickles; central leaflet 82 mm long, ovate, slightly cordate, gradually attenuate, acute, sometimes lobate to almost divided, width–length index 0.79–0.84, length of petiolule 17–24% of length of leaflet; lateral leaflets sessile. Flowering branch ( Fig. 18D ) angular, with rather numerous patent hairs, 5–10 acicular up to 1–2 mm long pricklets and 80–100 unequal stipitate glands. Leaves with broad dents. Inflorescence axillar, with 3–5 flowers; pedicels ( Fig. 18E ) ascendant, 2–3 cm long, with patent long hairs and many unequal stipitate glands and 2–6 acicles. Flowers: sepals green, densely long hairy and with stipitate glands, without prickles, patent; petals ( Fig. 18F ) white, large ovate, elliptical or obovate, 15–20 mm long, 9–11 mm wide, width–length index 0.60–0.70; stamens much shorter or longer than styles; anthers glabrous; ovaries (almost) glabrous. Ripe fruit black.

Ecology: —Woods and forest margins.

Distribution in South Africa: —Some places around Hogsback: along road S.E. of Hogsback and along road to Fort Beaufort, Eastern Cape.

Specimen:— SOUTH AFRICA. Eastern Cape: Hogsback, road to Fort Beaufort , 20 October 2018, Beek 2018.107 ( L) .

Notes: —Plants from Hogsback represent the shifting characters of R. macropetalus as these are described by Bailey (1925, 1941). The leaves can be 3- and 5-foliolate. Specimens in herbaria that were seen are all 3-foliolate; the plants in Hogsback are 3- to 5-foliolate, corresponding with Bailey’s description; sometimes the central leaflets are deeply incised; they can become pinnate. The serrature of the primocane leaves is rather sharp, those of the inflorescences are either sharp or obtuse [var. b of Hooker (1832: 178)]. Both can occur on the same plant. Plants of Hogsback are mainly obtusely serrate. Stamens of the plant on the Beaufort road are short, those of the plant south-east of the town are long. Plants were visited early in the season, at the beginning of flowering. New investigations in a later phase of development must confirm the identification.

It might be assumed that the plant in KwaZulu-Natal to which Sochor 2019 refers as a glandular specimen of R. sect. Flagellares (= Procumbentes) is also R. macropetalus .

Figures

FIGURE 18. Rubus macropetalus. A. Habit. B. Primocane. C. Leaf. D. Inflorescences. E. Pedicels and flower. F. Flower. Photographs: A. van de Beek.