Cyathea madagascariensis Kaulf.

Janssen, Thomas & Rakotondrainibe, France, 2006, A revision of the fern family Cyatheaceae in the Mascarene Islands, Adansonia (3) 28 (2), pp. 213-241 : 238-239

Cyathea madagascariensis Kaulf.

Enumeratio Filicum 257 (1824) as “ madagascarensis ”; Sprengel, Systema Vegetabilium 4: 127 (1827). — Cyathea canaliculata Willd. ex Spreng. var. rufescens Mett. ex Kuhn, Filices Africanae : 163 (1868). — Alsophila madagascariensis Willd. ex Kuhn , nom. inval. pro syn., Filices Africanae: 163 (1868). — Cyathea borbonica Desv. var. madagascariensis (Kaulf.) Bonap. , Notes ptéridologiques 9: 49 (1920); Tardieu in Humbert, Flore de Madagascar et des Comores, fam. 4: 13 (1951). — Cyathea borbonica Desv. f. madagascariensis (Kaulf.) C.Chr., Dansk botanisk arkiv 7: 21 (1932). — Type: “Habitat in Madagascaria”, A. du Petit-Thouars s.n. (holo-, B-W! no. 20166; putative iso-, P!).

REMARKS

Kaulfuss (1824: 257) does not cite any type material, but it is obvious from his account that he consulted Willdenow’s herbarium. The wording of his description of Cyathea madagascariensis is clearly based on the description in Willdenow’s hand glued on the cover of du Petit-Thouars s.n. in B-W! no. 20166. The specimen consists of two detached pinnae with rachis fragments bearing subpetiolulate, oblong, coriaceous pinnules, 1.8-2 × 0.3-0.4 cm, with rounded to subobtuse, subcrenate apices and revolute margins. The sori are contiguous and subcostular. The pinnae form a rather acute angle with the rachis and, as can be deduced from their position in the dried specimen, the pinnules were most likely conduplicate in the life plant. The same description applies to a specimen by du Petit-Thouars s.n. at P!, which consists of a rachis fragment carrying five pinna pairs and which we consider to represent a putative isotype.

Both specimens are morphologically very close to Cyathea borbonica var. sevathiana from Mauritius, and might agree with some forms of Cyathea borbonica var. borbonica from Réunion, but they do not correspond to any known material from Madagascar. Like in the previous case, the type material is too incomplete to be unambiguously determined and of doubtful geographic provenance. We hence prefer to refrain from epitypifying C. madagascariensis and leave its status unclarified in the present treatment.

Kuhn (1868: 163) publishes the name Cyathea canaliculata var. rufescens Mett. ex Kuhn without a description citing as only specimen “Thouars in hb. W. 20166” and in synonymy Alsophila madagascariensis Willd. , an unpublished name in Willdenow’s hand on the said specimen.

The epithet madagascariensis , based on the type in Willdenow’s herbarium, has been combined under Cyathea borbonica Desv. by Bonaparte (1920: 49; pro varietate), and Christensen (1932; pro forma). These authors and Tardieu-Blot (1951) do not cite additional material besides the type.