Alsophila bullata Baker

Janssen, Thomas & Rakotondrainibe, France, 2007, An update of the revision of Cyathea subgen. Alsophila sect. Gymnosphaera (Cyatheaceae) in Madagascar and the Comoros including a discussion of putative hybridization events, Adansonia (3) 29 (2), pp. 195-213 : 208

Alsophila bullata Baker

Journal of the Linnean Society, Botany, London 15: 412 (1876). — Cyathea bullata (Baker) Domin, Pteridophyta : 262 (1929). — C. bullata (Baker) Rakotondr. , Bulletin du Muséum d’Histoire naturelle, Paris, 4 e série, sect. B, Adansonia , 10 (4): 376 (1988), comb. superfl.; Rakotondrainibe & Lobreau-Callen, Adansonia , sér. 3, 21 (1): 141 (1999). — Type: Madagascar. “Intérieur de Madagascar ”, IV.1876, Pool s.n. (holo-, K!).

REMARKS

The holotype of Alsophila bullata Baker, Pool s.n. (K!), comprises two identical sheets carrying fragmentary specimens. Each sheet contains a single entirely fertile pinna lacking an associated rachis fragment. In the pinnules, five to six proximal segments are free and sessile, 1 × 0.3 cm and have a crenulate margin. Segments are progressively adnate and the distal segments are confluent. The sori are exindusiate and display small receptacular paraphyses, shorter than the sporangia. The costa has a dense hairy indument on its adaxial face and bullate as well as bicolorous lanceolate scales on its abaxial face. Taking into account our current knowledge of sect. Gymnosphaera , these two sheets may correspond to at least five taxa: C. boiviniiformis and its two varieties ( var. lobata , var. madagascarica ), C. impolita , or C. poolii . In the absence of sterile pinnules (dimorphism?), the leaf apex (distribution of fertile pinnae?), and the petiole base (scale morphology?), the material is ambiguous and the choice of an epitype to allow for a precise application of the name A. bullata Baker would be much more arbitrary than in the case of A. boivinii Mett. ex Ettingsh. The holotype of A. boivinii, Boivin s.n., collected in the Comoros, can be confounded with two taxa only, that are, according to the presently known material, not occurring in the Comoros. The holotype of A. bullata, Pool s.n., has been collected in Madagascar and can be confounded with five distinct Madagascan taxa. This difference led to the decision to epitypify A. boivinii , but to refrain from epitypification of A. bullata .