Asplenium majus (Hieron.) Pichi Sermolli (1983a: 134)

Fischer, Eberhard & Lobin, Wolfram, 2023, Synoptic Revision of Aspleniaceae (Asplenium, Hymenasplenium) of Rwanda, Phytotaxa 608 (1), pp. 1-65 : 21

Asplenium majus (Hieron.) Pichi Sermolli (1983a: 134) ( Fig. 7 , 8 ).

Asplenium goetzei var. major Hieron. (in Brause & Hieronymus 1910: 19).

Lectotype (designated by Pichi Sermolli 1983a: 134):— RWANDA. NO Kiwu, Karisimbi , Südkrater, 3300 m. Senecio u. Ericaceenbusch, November 1907, J.Mildbraed 1590 (B 20 0056654!).

Specimens seen:— Northern Province: Préfecture Ruhengeri (= Musanze), Parc des Volcans, Bisoke, bords du Lac, 3711 m, 13 February 1935, G.de Witte 2243 (BR0000024680783, BR0000024680837); Bisoke, 3620 m, op de bemoste Senecio stammen, 13 February 1972, P. Van der Veken 9366 (BR0000024680745); Sabinyo, flanc sud, 3359 m, epiphyte sur Philippia (= Erica ), 3350 m, 25 February 1972, P.Bamps 3236 (BR000024680790); Sabinyo, alt. 2820 m, 28 July 1974, P. Van der Veken PV 10409 (B 20 0084647); Sabinyo, alt. 2820 m, 28 July 1974, P. Van der Veken 10410bis (B 20 0085109, B 20 0084618); Muhavura (= Muhabura) flanc W, 3500 m, 1 August 1974, P. Van der Veken 10572 (BR0000024680752).

First recorded for Rwanda: — Brause & Hieronymus (1910: 19) as Asplenium goetzei var. majus .

Habitat: —Epiphyte on Erica , Dendrosenecio or Hagenia , elev. 2820–3711 m.

Distribution in Rwanda:—Northern Province: Volcano NP, Karisimbi, Bisoke, Sabinyo, Muhabura.

General distribution: —Africa: D.R. Congo, Rwanda, Tanzania.

Note: — Beentje (2008: 50) considers Asplenium majus as a synonym of A. actiniopteroides Peter (1929: 40) . We follow the opinion of Pichi Sermolli (1983a, 1985) and Viane (2021) and regard them as separate species.

Asplenium majus can easily be recognized by the dense viscid glands and the ovate-acuminate rhizome scales with broad base, an acuminate apex and a fimbriate margin (versus lanceolate rhizome scales not distinctly wider in Asplenium actiniopteroides ) ( Fig. 8 C, D ).

The presence of false veins on the lamina has already been stated by Hieronymus (in Brause & Hieronymus 1910). Chaerle & Viane (2004) made a systematic overview of false veins in a group of African high mountain (2000–4700 m) Asplenium species. False veins are narrow elongated abaxial epidermal cells running from the sinuses between marginal teeth towards the junction of two real veins, and lacking a vascular bundle ( Chaerle & Viane 2004). In A. actiniopteroides , A. goetzei Hieronymus (1900: 343) , A. majus and A. uhligii Hieronymus (1911: 374) real false veins occur, extending from the sinus to the junction of two real veins ( Chaerle & Viane 2004). In A. mildbraedii Hieron. in Brause & Hieronymus (1910: 2) the false vein is present from the sinus onwards, but does not reach the junction of two real veins, and in A. volkensii Hieronymus (1895: 83) false veins are absent.

Figures

FIGURE 7. Asplenium majus.—A. Habit.—B. Frond.—C, E, F. Detail of fronds.—D. Rhizome. Photographs: E.Fischer, A, B, C. Karisoke; D. Karisimbi; E. Humbert 8569; F. Humbert 8086. Scale bars:A, B. 5 cm; C. 1 cm; D, E, F. 1 mm. Reproduced with permission from BR (Meise).

FIGURE 8. Asplenium majus. A–E. Rhizome scales.—A. actiniopteroides. D, E. Rhizome scales,—F, G. Type of A. actiniopteroides. Scale bars A–G. 1 mm.