Janssen, Janssen & Rakotondrainibe, 2008

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 : 240-242

2. Cyathea perrieriana C.Chr. ( Figs 4 H-K; 46C; 47B)

Dansk Botanisk Arkiv 7: 19, pl. 3 figs 1-6 (1932);Tardieu in Humbert, Flore de Madagascar et des Comores, IVe famille, Cyathéacées : 6 (1951). — Alsophila perrieriana (C.Chr.) R.M.Tryon, Contributions from the Gray Herbarium 200: 31 (1970).— Type: Madagascar,forêt orientale,bassin inférieur du Mangoro, 300 m, X.1927, Perrier de la Bâthie 18086 (holo-, BM! [BM000800688]; iso-, P! [3 sheets]).

ADDITIONAL MATERIAL EXAMINED. — Madagascar. Toamasina, Maroantsetra , piste menant au sommet d’Ambohitsitondroinan’Ambanizana, 15°32’S, 50°00’30’’E, 620-1109 m, 23.X.2004, Janssen et al. 2503 ( MO, P, TAN), 2504 (P, TAN) , 2505 (P, TAN), 2511 (P, TAN). — Antsiranana, Andapa , RNI du Marojejy, 14°26’12’’S, 49°44’30’’E, 1200 m, 25.X.1996, Rakotondrainibe 3502 ( MO, P, TAN) . — Mahajanga, Sofia, Bealanana, Mt. Ampomotra , 14°12’58’’S, 49°04’12’’E, 1820 m, 24.X.2005, Rakotovao et al. 2337 ( MO, TAN) . — Ambohimirahavavy , 14°13’41’’S, 49°08’10’’E, 1992 m, XI.2005, Rakotovao et al. 2529 ( MO, P, TAN) . — Toamasina, PN de Zahamena, Ankosy , 17°41’08’’S, 48°59’43’’E, 650 m, 11.VI.2001, Rasolohery 467 ( MO, P, TAN) . — Toamasina, Masaola peninsula, Ambanizana , 15°38’S, 49°59’E, 300-700 m, 1.XI.1992, van der Werff et al. 12822 ( MO, P) .

FIELD OBSERVATIONS. — Trunk: HT up to 8 m, DT (5-)6-9(-12) cm, dead petiole bases caducous and the leaf scars exposed, sometimes a rudiment persistent in the upper part of the trunk; trunk surface dark brown, usually with persistent, dense scales like those of the petiole base.

Petiole: with 1 row of light brown to orange aerophores on either side; long to short sigmoid, often parallel to the trunk surface and more or less fasciculate above the trunk apex before being gradually recurved and arching.

Leaf scars: 2.5 × 3-4.5 cm, elliptic, 4 or 5 conical spines, up to 0.7 cm long, on their somewhat raised lower rim; light brown to white in the upper part of the trunk, spirally arranged.

Crown: umbrella-shaped with arching rachises, petioles more or less erect and the crown centre infundibuliform especially in young plants.

Trunk apex: densely covered with brown scales, concealed by or visible through the more or less spaced petiole bases.

Lamina: elliptic to ovate; LL 155-200(-350) cm, WL 110-125 cm, FW 65-75 cm, NP 12-15.

DESCRIPTION

Petiole: 20-85 cm long, 2.5-3 cm in diameter; completely violaceous to blackish brown, with a thin and caducous tomentum of brown squamules.

Lamina: bipinnate, coriaceous, pale green below, shiny green to dark green above, lamina base shortly attenuate to truncate, basal pinnae patent and often strongly conduplicate; rachis of the same colour as the petiole.

Largest pinnae: 45-60 cm long, distant by 10- 15 cm, adjacent pinnae contiguous to overlapping, their apex more or less truncate and the apical pinnule conform, i.e. resembling the lateral pinnules; costae and costulae of the same colour as the petiole.

Largest pinnules: 6-10 × 1.2-2.2 cm, spaced by less than their width, petiolulate, the petiolule 0.2- 0.5 cm long, articulated and the pinnules easily shed upon drying, lanceolate-oblong, straight, their margin subentire, serrate in the acute to distinctly caudate apex, their base cordate in proximal, truncate in distal pinnules, occasionally slightly mono- or biauriculate; veins once to twice furcate.

Scales and hairs: scales present from the petiole base upwards to 30-60 cm on the petiole, often reaching the first pinna pair, moderately dense, sometimes only slightly overlapping, persistent, narrowly triangular, 1.5-2(-3) × 0.1-0.2 cm, straight to slightly falciform (adaxial scales more or less contorted), shiny to dull, brown to dark brown, with a light brown erose margin, appressed, adaxial scales not appressed, antrorse, coriaceous, not indurated; scattered, dark brown acaroid squamules on the abaxial face of the costulae and veins; adaxial face of the costae densely tomentose with more or less contorted and antrorse, dark brown multicellular hairs and bearing sparse, filiform, brown scales; these scales also on the adaxial face of the rachis; leaf otherwise glabrous.

Sori: spaced by less than to more than their width, spaced from the costula by at least their width, about 0.1 cm in diameter, covering the entire pinnule except its apex; indusia globular, brown, membranous, at maturity dehiscing in (2-)3-4 lobes, often only a rudiment persistent as a collar around the base of the receptacle; receptacle capitate to disciform, usually longer than the rim of mature indusia, with inconspicuous filiform paraphyses much shorter than the sporangia.

DISTRIBUTION

Northern to Central Madagascar, most frequent on the Masoala peninsula; endemic.

ECOLOGY

(300-)600-1200(-2000) m. Dense evergreen rainforests.

REMARKS

Even from fragmentary specimens this taxon is usually easily recognized by its large and long petiolulate coriaceous pinnules with a cordate base, although the short dark brown petiole scales may be necessary to unambiguously differentiate it from its close relatives of group IIa. Cyathea perrieriana cannot be confounded with any other taxon of the Western Indian Ocean.

Juvenile plants (cf. Janssen et al. 2511) have light brown crispate scales and pinnate to bipinnate leaves, the pinnae or pinnules being ovate-oblong with rounded to obtuse apices.

Figures

FIG. 4. — A-E, Cyathea marattioides Willd.ex Kaulf.; A, pinna abaxially with a fragment of the rachis, sori only partly indicated;B, habit; C, pinnules abaxially with a fragment of the costa;D, scale from the base of the petiole; E, trunk segment with leaf scars;F, G, C. tsilotsilensis Tardieu; F, pinnules abaxially with a fragment of the costa; G, scale from the base of the petiole; H-K, C. perrieriana C.Chr.; H, pinnules abaxially with a fragment of the costa; I, trunk segment with leaf scars; J, scale from the base of the petiole; K, habit. A-E, Janssen et al. 2488 (P); F, G, van der Werff 12905 (P); H-J, Janssen et al. 2503 (P); K, uncollected, photograph at P. Scale bars: A, 5 cm; B, K, 1 m; C, E, F, H, I, 1 cm; D, G, J, 0.5 cm.