Cyathea leptochlamys Baker, 1887

Janssen, Thomas & Rakotondrainibe, France, 2008, A revision of the indusiate scaly tree ferns (Cyatheaceae, Cyathea subgen. Alsophila sect. Alsophila) in Madagascar, the Comoros and the Seychelles, Adansonia (3) 30 (2), pp. 221-376 : 256-257

8. Cyathea leptochlamys Baker

Journal of the Linnean Society 22: 535 (1887); Christensen, Dansk Botanisk Arkiv 7: 27, pl. 5 figs 17-19; Tardieu in Humbert, Flore de Madagascar et des Comores, IVe famille, Cyathéacées : 18 (1951). — Alsophila leptochlamys (Baker) R.M.Tryon, Contributions from the Gray Herbarium 200: 30 (1970). — Type: Madagascar, Baron 3665 (holo-, K! [K000009939]).

DESCRIPTION

Lamina: bipinnate, herbaceous (not coriaceous).

Largest pinnae: 36 cm long, apex shortly caudate, pinnatifid.

Largest pinnules: 4 × 0.8-1cm, spaced by less than to about their width, shortly petiolulate, but sessile in the upper third of the pinnae, oblong-triangular, their margin deeply crenate up to halfway to the costula in the lower two thirds of each pinnule, crenulate to subentire in the upper third, the apex acute in distal, obtuse in proximal pinnules; veins twice furcate to pinnate.

Scales and hairs: scattered multicellular hyaline hairs present on the abaxial face of the costae, costulae and veins; sori subtended by hyaline multicellular hairs, inserted on the veins near the base of the receptacle and more or less overtopping the rim of the indusia.

Sori: median, distant by more than their width, restricted to lower half of pinnules; mature indusia dehiscing irregularly, brown; receptacle capitate, paraphyses inconspicuous.

DISTRIBUTION

Madagascar; endemic?

TYPIFICATION AND SYNONYMY

Christensen (1932) suggested, that C. leptochlamys might be near C. mossambicensis Baker from con-

tinental Africa, but the latter species has pinnatepinnatisect leaves with broadly adnate pinnules. The African C. thomsonii Baker has bipinnate-pinnatifid leaves with sessile, profoundly lobed pinnules, but these are larger than in C. leptochlamys , up to 6 × 1 cm. Furthermore, only the basal 1-4 pinnule pairs are distinctly petiolulate and the distinct hairs inserted at the base of the receptacle are absent. The Madagascan C. decrescens var. quadrata has less distinctly petiolulate, smaller and less deeply crenate pinnules.

The holotype specimen consists of three detached pinnae, but cutting and indument make this a distinctive taxon. Currently, we are not aware of a Madagascan or African specimen, which sufficiently agrees with Baron’s fragmentary collection to be designated as an epitype.