Asplenium goetzei Hieronymus (1900: 343)

Fischer, Eberhard & Lobin, Wolfram, 2023, Synoptic Revision of Aspleniaceae (Asplenium, Hymenasplenium) of Rwanda, Phytotaxa 608 (1), pp. 1-65 : 57

Asplenium goetzei Hieronymus (1900: 343) ( Fig. 25 , D–F).

Holotype: — TANZANIA: Uluguru-Berge. Lukwangule-Plateau auf Bäumen , zwischen Flechten. 29 November 1898, W.Goetze 283 (B 20 0015728!).

Note: — Pichi Sermolli (1985) cites a specimen from Rwanda (Northern Province: Volcano NP, selle entre le Karisimbi et le Visoke, Ruhengeri (= Musanze), forêt-prairie à vieux Hagenia , épiphyte sur Hagenia 3000 m, 20 January 1972, P.Bamps 2963 [BR0000013601546!]) that he assigns to Asplenium goetzei : „The frond shows a considerable polymorphism both in the outline of the blade and in the shape of the pinnae, mainly in connection with the different value of the ratio between their length and breadth. This variability frequently occurs also in fronds from the same rhizome. However, the long-creeping rhizome, the structure of the paleae, the shape of the ultimate segments, long connected together and with a peculiar fissure in the line of connection, the apex of segments and the position of sori well characterize the species“ ( Pichi Sermolli 1985: 136). There is a similar specimen from Eastern D.R. Congo (Kahuzi-Biéga, Van der Veken 8864 ( BR 0000013601508) also representing A. uhligii .

The available keys are often insufficient to clearly separate Asplenium goetzei from A. uhligii . In the protologue from A. goetzii an important character „kriechende Rhizome, welche am Grunde von dunkelrostbraunen, nicht schwarzbraunen Schuppen bedeckt sind“ is cited by Hieronymus (1900: 344) („creeping rhizomes that are covered with dark rust-brown, and not blackish-brown scales“). We studied the scales of the type specimen ( Fig. 25 D–F ) which have reddish-brown thickened cell walls and can be easily distinguished from those of A. uhligii ( Fig. 25 A–C ). Thus, we agree with Beentje (2008) that typical A. goetzei is restricted to the Uluguru Mountains of Tanzania, and that the two cited specimens from Pichi Sermolli (1985) represent a form of A. uhligii . Therefore, A. goetzei does not occur in Rwanda.

Figures

FIGURE 25. Asplenium uhligii. Rhizome scales.—A–C, from type. Photographs: E.Fischer & W.Lobin.—Asplenium goetzei. Rhizome scales.—D–F, from type. Photographs: E.Fischer & W.Lobin. Scale bar: 1 mm.