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 : 312-316

31. Cyathea remotifolia Bonap.

( Figs 31 ; 46E ; 51C )

Notes ptéridologiques 5: 51 (1917); l. c. 9: 62 (1920). — Type: Madagascar, Toamasina, Andasibe, forêt d’Analamazaotra , 800 m, XII.1912, Perrier de la Bâthie 6121 (holo-, P! [P00404227]; iso-, P!) . — Madagascar, Antsiranana, Montagne d’Ambre, piste menant de la station forestière des Roussettes à la Route des Mille Arbres, 12°31’38’’S, 49°10’20’’E, 1130 m, 5.X.2004, Janssen et al. 2432 (epi-, P! [4 sheets: P00589640-43], here designated; isoepi-, P! [3 sheets], TAN!; one trunk surface mould at P!) .

Cyathea borbonica Desv. var. laevigata auct.: Bonaparte, Notes ptéridologiques 9: 49 (1920); Christensen, Dansk Botanisk Arkiv 7: 21, pl. 4 figs 18, 19 (1932); Tardieu in Humbert, Flore de Madagascar et des Comores, IVe famille, Cyathéacées : 14 fig. 1 (6-7).

ADDITIONAL MATERIAL EXAMINED. — Madagascar. Antsiranana, Mt. d’Ambre, 12°31’S, 49°08’E, 800-1000 m, VII.1993, Andrianantoanina et al. 212 (P). — Idem, 12°30’S, 49°10’E, 800-1000 m, VII.1993, Andrianantoanina et al. 215 (P). — Toamasina, Andasibe, Ambatovy forest, 18°50’36’’S, 48°19’55’’E, 979 m, 16.I.2005, Antilahimena et al. 3178 (MO, P). — Antsiranana, Mt. d’Ambre, 12°31’30’’S, 49°10’20’’E, 1050 m, 20.X.1988, Badré et al. 2100 (P). — Baron 3187 (BM, K), 3784 (B, K), 6304 (BM). — Antsiranana, 13°47’52’’S, 48°48’22’’E, 1100-1300 m, 17.IV.2000, Birkinshaw et al. 715 (P). — Antananarivo, Mandraka, 18°55’30’’S, 47°55’10’’E, X.1948, Corrèard s.n. (P). — Tampoketsa de Tsaratanana, forêt d’Analimahandanivatsy, 16°35’30’’S, 47°53’E, 1200 m, 28.VIII.1941, Cours 1621 (BR, K, MO, P). — Antananarivo, Anjozorobe, 18°23’30’’S, 47°53’E, 1200 m, 21.I.1944, Cours 1768 (P); 2117 (P). — Montagne d’Ambatosoratra, 14°46’S, 48°52’E, Cours 3255 (P). — Fianarantsoa, Ambatofitorahana, 20°49’S, 47°11’E, 1000 m, 5.III.1951, Cours 4033 (P). — Dpt de Brickaville, d’Andrambolahy kely à Andranampony, 18°50’S, 49°04’E, 300 m, 21.IV.1951, Cours 4499 (P); 4502 (P). — 100 km W Tsiromandidy, vers Maofenobe, 22.VII.1974, Cremers 3289 (P). — Antananarivo, Mandraka, 18°55’30’’S, 47°55’10’’E, 13.VIII.1906, D’Alleizette 70 (P). — Idem, 15.VIII.1906, D’Alleizette 87 (P). — Prov. Mahajanga, NW of Ambohitsaratelo- Bebao, 18°22’S, 45°35’E, 1200 m, 13.I.1985, Dorr et al.3521 (P). — Fianarantsoa, Mansarivolo-Andrianony, 22°17’S, 46°52’E, 1300 m, 4.XI.1970, Guillaumet 3508 (P). — N des Chaînes Anosyennes, 24°25’S, 46°58’30’’E, 700 m, 27.XI.1971, Guillaumet 3981 (P). — Massif de l’Andohahela, vallée de Ranohela, X.1928, Humbert 6109 (BM, P). — Toliara, Andohahela, col de Tsilotsilo, 24°50’S, 46°45’30’’E, 1300 m, II.1934, Humbert 14129 (P). — Antsiranana, Tsaratanana, haute vallée du Sambirano, 13°57’S, 48°52’E, 1600 m, XII.1937, Humbert 18292 (P). — Massif du Marojejy, E d’Ambalamanasy, 14°31’30’’S, 49°35’30’’E, 450-800 m, 1948, Humbert et al. 22104 (K, P). — Fianarantsoa, Andrambovato, 21°31’S, 47°25’E, 800-1000 m, I.1955, Humbert 28454 (P). — Antsiranana, Montagne d’Ambre, 12°31’53’’S, 49°10’16’’E, 1132 m, 6.X.2004, Janssen et al. 2443 (MO, P, TAN). — Toamasina, RNI Betampona, Rendriendry, 17°55’48’’S, 49°12’E, 310-580 m, 6.XI.2004, Janssen et al. 2535 (MO, P, TAN). — Idem, Rendriendry, piste Betakonana, 17°55’54’’S, 49°12’12’’E, 300-500 m, 8.XI.2004, Janssen et al. 2561 (MO, P, TAN). — Antananarivo, Mandraka, 18°55’30’’S, 47°55’10’’E, 1200-1250 m, 13.XI.2004, Janssen et al. 2582 (MO, P, TAN). — Fianarantsoa, Ivohibe, corridor forestier entre RS d’Ivohibe et PN d’Andringitra, 22°25’14’’S, 46°55’38’’E, 1180 m, 21.IV.2005, Janssen et al. 2802 (MO, P, TAN). — Mahajanga, massif du Tsaratanana, entre Antetikalambazaha et Mangindrano, 14°11’24’’S, 48°56’44’’E, 1670-1700 m, 15.V.2005, Janssen et al. 2960 (MO, P, TAN). — Jardin Botanique de Tananarive 2091 (P). — Antananarivo, Sarobaratra, 19°40’S, 47°33’E, 27.VIII.1937, Jardin Botanique de Tananarive 2884 (P). — Toamasina, Andasibe, Analamazaotra, 18°56’S, 48°26’E, 4.XI.1970, Keraudren-Aymonin et al. 25349 (P), 25350 (P). — Toamasina, Didy, forêt de Tsiazomborona, 18°07’S, 48°32’40’’E, 20.XI.2005, Labat et al. 3575 (P). — Tsiroanomandidy, 11.II.1966, Peltier 5671 (P). — Toamasina, forêt d’Analamazaotra, 18°56’S, 48°26’E, 800 m, XII.1912, Perrier de la Bâthie 6122 p.p. (P). — Antsiranana, Montagne d’Ambre, 12°37’S, 49°09’30’’E, 800 m, IX.1909, Perrier de la Bâthie 7500 (P). — Tampoketsa de Tsaratanana, entre Mahazamba et Bemarivo, 16°35’30’’S, 47°53’E, 1400 m, VII.1920, Perrier de la Bâthie 13209 (P). — Mt. Takarandoha, W de Vatomandry, 19°20’S, 48°59’E, 400 m, XII.1921, Perrier de la Bâthie 14125 (BM, P). — Massif de Tsaratanana, Centre, 14°02’30’’S, 48°57’30’’E, XII.1992, Perrier de la Bâthie 15256 (P). — Mahajanga, Analamaitso, 16°11’30’’S, 48°08’30’’E, 800 m, VIII.1907, Perrier de la Bâthie 15841 (P). — Forêt d’Ambre, 12°37’S, 49°09’30’’E, IX.1926, Perrier de la Bâthie 17757 (BM, P). — Fianarantsoa, corridor entre les PN de Ranomafana et d’Andringitra,WNW d’Ambatofotsy, 21°44’S, 47°24’E, 760 m, 3.XI.2000, Rabarimanarivo et al. 111 (P). — Idem, WNW d’Ikongo, 21°49’17’’S, 47°24’50’’E, 700 m, 19.XI.2000, Rabarimanarivo et al. 153 (P). — Antananarivo, RS d’Ambohitantely, NW d’Ankazobe, 18°10’S, 47°17’E, 1200-1650 m, 18.IV.1985, Rakotondrainibe 409 (P). — Idem, 24.VI.1983, Rakotondrainibe 457 (P, TAN). — Antsiranana, Montagne d’Ambre, Lac Texier, 12°32’S, 49°10’E, 1050 m, 24.VI.1992, Rakotondrainibe 1745 (MO, P). — Forêt d’Ambre, versant ouest, 12°32’S, 49°10’E, 1160 m, 19.VII.1992, Rakotondrainibe 1786 (MO, P). — Antsiranana, RS d’Anjanaharibe-Sud, SSW de Befingotra, 14°45’18’’S, 49°30’18’’E, 800 m, 19.X.1994, Rakotondrainibe et al. 2105 (K, MO, P, TAN). — Idem, 850 m, 24.X.1994, Rakotondrainibe et al. 2187 (P). — Fianarantsoa, RNI d’Andringitra, berges de la rivière Sahanivoraky, 22°13’40’’S, 47°01’30’’E, 800 m, 16.V.1995, Rakotondrainibe 2590 (P, TAN). — Idem, 22°15’S, 47°01’E, 20.V.1995, Rakotondrainibe 2676 (P). — Toliara, Tolanaro RNI d’Andohahela, NW du village d’Eminiminy, 24°35’S, 46°44’30’’E, 840 m, 29.X.1995, Rakotondrainibe 2968 (P, TAN). — Idem, 800 m, 29.X.1995, Rakotondrainibe 2989 (MO, P, TAN). — Idem, 30.X.1995, Rakotondrainibe 3006 (P, TAN). — Idem, 820 m, 1995, Rakotondrainibe 3017 (P, TAN). — Idem, 24°33’30’’S, 46°43’E, 8.XI.1995, Rakotondrainibe 3051 (P). — Idem, 24°34’S, 46°43’E, 1500 m, 20.XI.1995, Rakotondrainibe 3150 (P). — Fianarantsoa, RS d’Ivohibe, 22°28’12’’S, 46°57’36’’E, 850-950 m, 6.X.1997, Rakotondrainibe et al. 4003 (P), 4004 (MO, P, TAN). — Idem, 7.X.1997, Rakotondrainibe et al. 4050 (P, TAN). — Idem, 8.X.1997, Rakotondrainibe et al. 4067 (P). — Fianarantsoa, corridor entre les réserves d’Andringitra et d’Ivohibe, ESE d’Angodongodona, 22°25’36’’S, 46°56’18’’E, 880-950 m, 16.XI.1997, Rakotondrainibe et al. 4388 (P). — Antananarivo, RS d’Ambohitantely, 18°12’S, 47°17’E, 1400-1450 m, 6.XII.1997, Rakotondrainibe 4422 (P). — Antsiranana, forêt de Betaolana, NW d’Ambodiangezoka, 14°32’18’’S, 49°26’18’’E, 800-820 m, 10.X.1999, Rakotondrainibe et al. 4891 (P, TAN). — Antsiranana, massif d’Anjanaharibe-Sud, forêt d’Analabe, SW de Befingotra, 12°30’20’’S, 49°31’20’’E, 26.X.1999, Rakotondrainibe 5038 (P). — Idem, 27.X.1999, Rakotondrainibe 5067 (P). — Fianarantsoa, PN de Ranomafana, forêt de Vatoharanana, 21°16’S, 47°26’E, 3.X.2000, Rakotondrainibe et al. 5841 (P), 5847 (K, P). — Antsiranana, PN de Marojejy, SE de Doany, 14°25’36’’S, 49°36’30’’E, 800- 850 m, 14.X.2001, Rakotondrainibe et al. 6230 bis (K, P, TAN). — Vohemar, forêt de Binara, SW de Daraina, 6.XI.2001, Rakotondrainibe et al. 6524 (K, P). — Andapa, Doany, forêt d’Ankarongameloka, 14°15’29’’S, 49°26’20’’E, 1235 m, 10.III.2006, Rakotovao et al. 2945 (MO, P, TAN). — Fianarantsoa, Ranomafana, 21°18’S, 47°38’30’’E, 17.XI.1994, Randriambololona 278 (P). — Antsiranana, RNI de Tsaratanana, E de Beangona, 14°14’40’’S, 48°39’50’’E, 1550 m, 29.XI.2000, Rasolohery 143 (MO, P, TAN). — Toamasina, Zahamena, Ankosy, 26.I.2001, Rasolohery 184 (P). — Antenina, 17°53’S, 49°25’E, 3.II.2002, Rasolohery 650 (P). — Fianarantsoa, Ranomafana, 21°16’S, 47°25’E, 1000 m, II.1989, Schatz 2580 (P). — Idem, 21°13’30’’S, 47°27’30’’E, 900 m, 10.X.1992, van der Werff et al.12661 (P). — Antananarivo, Anjozorobe, 18°23’30’’S, 47°53’E, 1250 m, 6.XI.1992, van der Werff et al. 12846 (P). — Idem, 18°23’30’’S, 47°53’E, 1250 m, 6.XI.1992, van der Werff et al. 12848 (P). — Toliara, RNI d’Andohahela, NW Eminiminy, 24°38’S, 40°46’E, 500-1000 m, 6-12.II.1993, van der Werff et al. 12881 (G, MO). — Mahajanga, Andribe, 16°11’S, 48°56’E, 1500 m, 21.X.1994, van der Werff et al. 13547 (MO, P).

FIELD OBSERVATIONS. — Trunk: HT up to 8 m, usually 2-4 m, DT 3.5-6(-8) cm, dead petioles caducous and the leaf scars exposed; trunk surface ferruginous or light to greyish brown, smooth; the trunk may rarely develop ramifications, most likely as a result of a previous injury.

Petiole: with 1 or 2 irregular rows of whitish to light brown aerophores, distributed over the entire abaxial surface near the petiole base; petiole base short to long, but always distinctly sigmoid.

Leaf scars: 1.5-2 × 2-5 cm, obovate to narrowly elliptic, flat or slightly raised, much spaced to rarely contiguous; with 3-7 strong, acroscopic, conical spines, that are up to 1.5 cm long, caducous in older trunks; sometimes several orifices below the scar; spirally arrranged.

Crown: not dense, more or less umbrella-shaped.

Trunk apex: young croziers densely covered with soft, caducous, brownish scales, completely concealed among the very close standing petiole bases.

Lamina: widely elliptic; LL (90-)105-160(-200) cm, WL 50-75 cm, FW 55-70 cm, NP 13-30.

DESCRIPTION

Petiole: (8-)20-40(-70) cm long, 1-2 cm in diameter; green to stramineous, reddish to violaceous brown on abaxial face.

Lamina: pinnate-pinnatisect, herbaceous (not coriaceous), pale green below, shiny light to dark green above, lamina base attenuate, basal pinnae gradually reduced in size, but not reaching the petiole base, reflexed, more or less conduplicate, usually very distinctly caudate; rachis of the same colour as the petiole.

Largest pinnae: 25-40 cm long, distant by 5-9 cm, adjacent pinnae spaced by less than their width to overlapping, usually widest above the middle, their apex shortly caudate, pinnatifid; costae and costulae green.

Largest pinnules:(2.5-)3-5.5 ×(0.4-)0.5-0.8(-1)cm, spaced by less than to about their width, never contiguous, broadly adnate to the costa, more or less strongly decurrent, straight, but in their apical half sometimes falciform, their margin entire, crenulate near the apex, rarely deeply crenate-lobate, their apex acute to rounded, usually gradually more sharply pointed from proximal to distal pinnules, the first proximal pinnule pair sometimes sessile; veins once to twice furcate.

Scales and hairs: scales of the petiole base very caducous, densely imbricate and appressed to the croziers, but petioles of adult leaves more or less naked, rarely with some persistent scales near the petiole base, scales narrowly triangular, soft, 1-2 × 0.2-0.3 cm, straight, dark to light dull brown with a darker centre, but young scales with a shiny centre, margin laciniate-erose, scales quickly withering and often agglutinating before they fall, not indurated, but somewhat thickened at their base, leaving a hardly visible wart-like trace when shed; sparse to moderately dense, appressed, antrorse, brown multicellular hairs on the adaxial face of the rachis and costae; leaf otherwise glabrous.

Sori: subcostular, spaced by about to more than their width, about 0.1 cm in diameter, covering the entire pinnule or its lower half only; indusia globular when young, light brown to stramineous, membranous, caducous, i.e. at maturity only an appressed collar-like rudiment persists around the base of the receptacle; receptacle disciform to capitate, usually longer than the rim of mature indusia, with inconspicuous hyaline to reddish filiform paraphyses, sometimes with very short scaly paraphyses on its apex.

DISTRIBUTION

Madagascar, eastern rainforests from North (Montagne d’Ambre) to South (Andohahela); endemic.

ECOLOGY

(300-) 800-1600 m. Dense evergreen rainforests.

REMARKS

The closely related Madagascan species C. remotifolia and C. emilei differ, among other characters, from the Mascarene C. borbonica Desv. by their pinnules being broadly adnate to the costa. Cyathea remotifolia has a smooth trunk surface with conspicuous conical spines on the lower rim of the leaf scars and membranous, light brown to hyaline indusia that are persistent as a collar-like rudiment at the base of the receptacle, and a herbaceous (not coriaceous) lamina. Th ese characters distinguish it from C. emilei . In their natural habitat, both species can be quickly and easily distinguished when observing the trunk surface. However, determination of herbarium specimens not annotated with trunk characters may be difficult in rare cases, because pinnule shape is variable in both species and valvately opening globular indusia exist in a minority of specimens of C. remotifolia , although these are then lighter coloured and thinner than in C. emilei .

Some specimens have deeply crenate pinnule margins (cf. Rakotondrainibe 2968, 3051, 4388). Few specimens have a light brown to hyaline, membranous indusium, which is irregularly lobed and persistent in mature leaves, not reduced to a collar at the base of the receptacle (cf. Andrianantoanina 212, 215, Guillaumet 3981, Humbert 6109, Rabarimanarivo 153, Rakotondrainibe 3150). Such plants are occasionally collected over the entire range of the species and we believe that sorus age and drying conditions are responsible for the observed variation. Very thin trunks with contiguous leaf scars are preserved in a few specimens (cf. Rakotondrainibe 1786, 6230bis). Th e petiole scales of Rakotondrainibe 3150 are up to 1.5 cm long, brown and persist on the petiole and the lower part of the rachis.

Young plants usually have leaves with decrescent basal pinnae, which are light green, reflexed and divided into acute, serrulate segments (as opposed to C. emilei ). Very young trunkless plants, e.g., Janssen et al. 2561, have stramineous scales ascending up to 20 cm on the petiole and rachis.

TYPIFICATION AND SYNONYMY

This taxon has previously been determined as C. laevigata Willd. ex Kaulf. ( Christensen 1932; Tardieu- Blot 1951; pro forma C. borbonicae ). It differs, however, from C. laevigata by its pinnules being broadly adnate to the costa, not sessile, and it is most likely not closely related to the Mascarene endemic C. borbonica ( Janssen & Rakotondrainibe 2006) .

Two sheets of Perrier de la Bâthie 6121 are available at P.The holotype,identified as “Original”by Bonaparte, is composed of a leaf base, a young and a mature leaf apex.Th e middle part of a leaf constitutes the isotype sheet. Young sori and the lamina are covered with pluricellular hairs frequently found in young leaves, but are of no taxonomic value.Th e type specimen has the characteristic collar-like rudimentary membranous indusium characteristic for the taxon, but it does not preserve nor mention the distinctive features of the species’ trunk surface. To unambiguously associate these with the present taxon we designate an epitype including a trunk surface mould.Th e epitype specimen designated here also includes a very young leaf with adherent scales. Further samples of very young scaly croziers are included in some recent collections.

Pinnule shape in C. remotifolia is variable ranging from linear, oblong pinnules with rounded apices and rather large sinuses (including the type of the species) to forms with acute pinnule apices and narrow sinuses between the decurrent pinnules (more frequently observed and including the epitype designated here). Transitions between these forms are gradual and no formal recognition of the observed variation is possible. None of these forms possess long receptacular paraphyses or short shiny brown petiole scales and we believe that the assignment of the type of C. remotifolia to C. simulans by former authors ( Christensen 1932; Tardieu-Blot 1951; pro forma C. borbonicae ) resulted from a lack of suffi cient material for comparison.

Figures

FIG. 31.— Cyathea remotifolia Bonap.:A, pinnae abaxially with a fragment of the rachis,sori only partly indicated;B, pinnules abaxially with a fragment of the costa, sori only partly indicated; C, habit; D, sori on the abaxial face of a pinnule, the sorus in the centre with an irregularly dehisced indusium, all other sori with showing rudimentary indusia usually reduced to a collar-like structure at the base of the receptacle; E, basal part of the leaf (from the petiole base up to the fifth pinna pair); F, scales from the base of the petiole (left:a group of agglutinated scales;right:a single scale);G, leaf scars with prominent spines and smooth trunk surface.A,B, D, E, Janssen et al. 2432 (P); C, F, Janssen et al. 2582 (P); G, Janssen et al. 2443 (P). Scale bars: A, E, 5 cm; B, G, 1 cm; C, 1 m; D, 0.1 cm; F, 0.5 cm.

FIG. 46. — Distribution maps for Cyatheaceae (genus Cyathea) of Madagascar and the Comoros. Species are arranged in alphabetical order.

FIG. 51. — Photographic documentation of field characters in Cyathea: A-E, habit; A’-E’, trunk apex; A”-E”, trunk surface at breast height; A-A”, Cyathea madagascarica Bonap.; B-B”, C. melanocaula Desv.; C-C”, C. remotifolia Bonap.; D-D”, C. concava Bonap.; E-E”, C. dregei Kunze; A”, persistent dead petiole bases removed from the trunk in the upper half of the picture; E, erect habit (above), creeping habit (below); E”, branched creeping trunks. A-A”, Janssen et al. 2829; B, E, uncollected; B’, B”, Janssen et al. 2608; C, C’, Janssen et al. 2582; C”, Janssen et al. 2432; D, D”, Janssen et al. 2565; D’, Janssen et al. 2579; E’, Janssen et al. 2967; E”, Janssen et al. 2779. Vouchers at P. Photos B’, B”, C’, D’ by G. Rouhan (MNHN); all other photos by T. Janssen. Scale bars: A-E, 1 m; A’-E’, A”-E”, 10 cm.