Rubus apetalus Poiret (1804: 242)

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 : 20-21

a. Rubus apetalus Poiret (1804: 242) .

Type:— RÉUNION. = Ile de Bourbon, Commerson s.n. (holotype P-JUSS, Jussieu 14322 + A). ( Figs 5A–B )

Scrambling shrub with stems attaining several metres in length, whitish tomentose; prickles not numerous, scattered, 2–3 mm long, straight or curved. Leaves uneven pinnate, attaining 20 cm in length, including petiole of 7 cm; leaflets 5–7, ovate or elliptic, rounded or obtuse at base, acute at apex, with dented margins (2–)3–9 × (1–)1.5–5.0 cm; petiolule 0.2–1.0 cm long; terminal leaflet ± rhombic, sometimes connected with last lateral leaflet; abaxially of blade covered with short, dense, white tomentum, from which emerge longer hairs, more scattered and mixed with short reddish glandular hairs; adaxially with less dense tomentum leaving epidermis visible; stipules linear, 7–12 mm long, inserted on 2–3 mm at base of petiole. Floricane diam. 5 mm, with dense appressed stellate hairs; prickles 2 per 5 cm, curved, from 2–3 mm wide base 2.5–3.0 mm long. Flowering branch roundish to bluntly angular, with very dense appressed and patent rather short hairs; prickles unequal, from 1.0– 2.5 mm broad base declining, and curved, up to 2 mm long; stipules 9–11 mm, linear. Leaves pinnate 5- to 7-foliolate, adaxially rather densely tomentose with very few appressed longer hairs, abaxially grey to white tomentose and with some appressed hairs mainly on nerves; serrature with sharp forward directed teeth, some or all with forward directed thick mucros; petiole 2–5 cm long, with 1–5 tiny curved prickles, densely short hairy; central leaflet 44–75 mm long, elliptic-ovate, with subemarginate or rounded base, gradually attenuate into short tip, width–length index 0.38–0.66, length of petiolule 16–36% of length of leaflet; petiolule of the lower basal leaflets 0–3 mm. Inflorescence dense, pyramidal, with 3–6 axillary branches, very densely rather short hairy, with scattered tiny curved pricklets; peduncles patent or slightly ascending, longest with 10–40 flowers; pedicels 2–10 mm, densely tomentose and rather short hairy, with some straight pricklets. Flowers: sepals narrow, acute to rather long pointed, 1.5–3.0 × 6–9 mm, clasping, grey, densely tomentose and short hairy, with many (sub-)sessile glands, unarmed; petals absent; anthers glabrous; ovaries densely short hairy; receptacle densely hairy.

Notes: —Because of the lack of clarity about R. apetalus , a full description was given here; the details of the primocane were borrowed from Friedmann (1997), those of the flowering branch are based on material in L, P, and PRE and checked with the description of Friedmann (1997).

Besides the type, there is another specimen that was collected by Commerson on Réunion ( P02579813 ). It may be an isotype, but this is not absolutely certain. It evidently belongs to the same taxon. Another sample in P ( P02579812 ) might also be a collection by Commerson; it is however from another locality and obviously a mixture, as the leaves of the righthand piece are abaxially green, and the serrature is different.

Poiret (1804) mentions in the protologue ‘this plant grows in the plains and on the highlands of the Caffrerie, on the Ile de France’ . The specimens of Commerson, including the type, are, according to the labels, not from Île de France (= Mauritius), but from Île de Bourbon (= Réunion) where Commerson collected the type specimen. The reference to Île de France is obviously a mistake, as Gustafsson (1934) already suggested. It is not probable that Poiret saw any other plant than the type.

Gustafsson (1934) interprets the two geographical phrases as two localities: next to the Île de France also the ‘ Caffrerie’, which he identifies as the Caffrerie on the continent, the part of South Africa east of the Cape Colony , so east of the Keiskamma River . However, the ‘ Caffrerie’ refers to the ‘plaine des Cafres’ on Réunion . Commerson wrote on the label of the type: ‘Framboisier des hauts et de la plaine des Cafres’.

Poiret (1804), in the protologue, writes that the upper surfaces of the leaves would be glabrous, but in fact they have very short hairs, as Gustafsson (1934) already noted, though at first sight they seem to be glabrous.

The most conspicuous characteristic of R. apetalus is the serrature of the leaves with sharp forward directed teeth, some or all with forward directed thick mucros.

Specimens:— RÉUNION. ‘ Rubus tomentosus . Bois sur les verges des ravines et torrents’, Richard 167 ( P 02579807 /8); ‘Dans les forêts et sur les verges des ravines; Elle n’est pas commune’, Richard 182 ( P 02579806 ) ; Sentier vers plaines des Affouches, Friedmann 2288 ( P 02579792 /3); Sentier de la Roche Écrite, above St. Denis , 1200 m, 19 March 1974, Coode 4527 ( P 02579794 /8); Tour le long du chemin de … [?], Petit-Thouars s.n. ( P 02579799 ) ; Mare Sèche, Cilaos, 1200 m, Cadet 6614 ( P 02579800 ) ; Hauts du Bois des Nègles St. Paul , 1500 m, Cadet 4785 ( P 02579801 ) ; Plaine de Salazes , 1957, Alphonsine s.n. ( P 02579802 ) ; Forêt hygrophyle de Bébour, 1300 m, December 1971, Cadet 3380 ( P 02579803 ) ; Sentier de Cerand Ilet au Col de Fourches , Cirque de Salazie, 1500 m, 29 November 1973, Cadet 4541 ( P 02579804 ) ; Richard s.n. ( P 02579805 ) ; Richard s.n. ( P 02579809 ) ; July 1837, Gaudichaud s.n. ( P 02579810 ) ; Frappier 393 ( P 02579811 ) ; Ste Agathe, 18 July 1875, De l’Isle 386 ( P 02579814 /5); Boivin s.n. ( P 02579817 ) .

Figures

FIGURE 5. Rubus ser. Apetali. A. R. apetalus, type in P-JUSS. B. R. apetalus, type in P-JUSS, label. C. R. cryptopetalus, holotype, primocane. D. R. cryptopetalus, holotype, inflorescence. E. R. cryptopetalus, type, primocane leaves abaxially. F. R. cryptopetalus, type, primocane. G. R. cryptopetalus, type, flowering branch. H. R. cryptopetalus, type, leaves inflorescence. I. R. cryptopetalus, type, sepals and fruits. Photographs: A. van de Beek.