Cyathea orthogonalis Bonap.
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: 308-312
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|Cyathea orthogonalis Bonap.|
Notes ptéridologiques 5: 32 (1917); Bonaparte, Notes ptéridologiques 5: 29 (1917), nom. nud.; Christensen, Dansk Botanisk Arkiv 7: 24, pl. 5 figs 26, 27 (1932); Tardieu in Humbert, Flore de Madagascar et des Comores, IVe famille, Cyathéacées : 11 (1951). — Alsophila orthogonalis (Bonap.) R.M.Tryon, Contributions from the Gray Herbarium 200: 31 (1970). — Type: Madagascar, Baron 6126 (holo-, P! [P00338265]; iso-, P!, K!). — Madagascar, Antananarivo, Anjozorobe, forêt d’Andranomay, 2 km au NE d’Andranomay, 13 km au SE d Anjozorobe, 18°28’48’’S, 47°57’18’’E, 1300-1450 m, 16.XII.1996, Rakotondrainibe 3754 (epi-, P! [3 sheets: P00084603- 05], here designated).
ADDITIONAL MATERIAL EXAMINED. — Madagascar. Toamasina, Zahamena National Park, Andranomalaza Atsimo, 17°39’40’’S, 48°39’30’’E, 1182 m, 24.X.2000, Birkinshaw et al. 752 (P). — District d’Ambatondrazaka , Onibe , 17°50’S, 48°25’E, 850 m, XI.1938, Cours 1198 (P). — Forêt de Didy , 18°07’S, 48°32’40’’E, 1000 m, 8.XI.1941, Cours 1631 (P). — Est de Moramanga , 18°56’S, 48°13’E, 1000 m, 22.XI.1942, Cours 1739 (P). — Antananarivo, Anjozorobe , 18°23’30’’S, 47°53’E, 1200 m, 21.I.1944, Cours 1769 (P). — Massif de l’Andringitra , forêt Ambodipaiso , 21°17’S, 47°34’E, 1100 m, 12.I.1945, Cours 2281 (P). — Fianarantsoa, Antsiranana, Ambatofitorahana , 20°49’S, 47°11’E, 1000 m, 6.III.1951, Cours 4124 (P). — Didy , SE of Lac Alaotra, 17°56’37’’S, 48°27’20’’E, 1130 m, 28.I.1995, du Puy et al. 805 (K, MO, P, WAG). — Lac Alaotra , 17°33’S, 48°25’E, Jardin Botanique Tananarive 4341T (P). — Toamasina, RN de Zahamena, massif de l’Andrangovalo, 17°40’S, 48°45’E, 1000 m, X.1937, Humbert et al. 17607 (P), 17610 (P). — Toamasina, PN de Zahamena, Antanandava, 17°29’S, 48°44’E, 1107 m, 26.I.2001, Rasolohery 203 ( MO, P, TAN). — Idem, 917-1020 m, 2.II.2002, Rasolohery 628 ( MO, P, TAN). — Zahamena, Manakambahiny Est, NW Androrangabe, 17°40’34’’S, 48°45’32’’E, 1100 m, 17.IX.2002, Rasolohery 720 ( MO, P, TAN). — Ambatondrazaka, Sahamalaza, Onibe, 17°44’07’’S, 48°43’01’’E, 1010 m, 2.III.2001, Ratovoson et al. 451 ( MO, P) GoogleMaps .
FIELD OBSERVATIONS. — Trunk: HT up to 6(-10) m, DT 6-12 cm, dead petioles caducous and the leaf scars exposed, rudiments of the petiole base persistent in the upper part of the trunk; trunk surface smooth, blackish brown, rarely with persistent scales.
Petiole: base sigmoid.
Leaf scars: 2 × 3 cm, obovate to elliptic, sometimes rounded, somewhat raised, their rim not spiny.
Crown: a flat umbrella.
Lamina: LL 150-300 cm, NP 46-58.
Petiole: about 10-20 cm long, 1-1.5 cm in diameter and dark brown when dry.
Lamina: pinnate-pinnatisect, very coriaceous, shiny dark green above, dull pale green below, lamina base attenuate, but pinnae not decrescent down to the petiole base; basal pinnae spaced by about to more than their width, distinctly petiolate and with an acute base, patent, i.e. their costae are perpendicular to the rachis; rachis green to brown when fresh, light brown when dry.
Largest pinnae: 33-38 cm long, spaced by 5-5.5 cm, adjacent pinnae not overlapping, spaced by less than their width to contiguous, their apex acute, pinnatifid; costae and costulae of the same colour as the rachis.
Largest pinnules: 2-2.5 × 0.5-0.6 cm, spaced by less than their width to almost contiguous, up to 3 proximal pinnule pairs sessile, others broadly adnate to the costa, oblong, straight and costulae perpendicular to the costa or slightly falciform, margin entire, crenulate near the acute to obtuse apex; veins once furcate.
Scales and hairs: scales present from the petiole base upwards to at least 40 cm on the petiole and rachis, persistent, narrowly triangular, 1.5-2 × 0.2-0.3 cm, never straight, not appressed to the petiole and variously contorted, dull to shiny dark brown, with a narrow, light brown, erose margin, slightly indurated at their base, the adaxial lateral scales narrower, i.e. about 0.1 cm wide; dense dark brown, patent to antrorse, stiff, multicellular hairs on the adaxial face of the rachis and costae; some dark brown acaroid squamules on the abaxial face of the costulae, but leaf otherwise glabrous.
Sori: subcostular, contiguous to spaced by less than their width, less than 0.1 cm in diameter, covering entire pinnules or the lower three quarters; indusia globular, light brown, membranous, at maturity dehiscing in 2-4 lobes or irregularly; receptacle capitate, shorter than the rim of mature indusia, with conspicuous filiform paraphyses shorter than the sporangia.
Central Madagascar: Anjozorobe to Zahamena; one specimen collected near Antsirabe; endemic .
850-1300 m. Dense evergreen rainforests.
We here provide the first complete description of this taxon including characters of the petiole scales and trunk. Although many more or less complete collections exist, these have been frequently misidentified as C. bellisquamata and related species. Although distinct by its coriaceous, acute pinnules carrying comparably small sori, C. orthogonalis is most easily identified by its patent, petiolate basal pinnae, the appressed and contorted dark brown scales and a smooth trunk surface. Cyathea pseudobellisquamata is very near C. orthogonalis but differs by its spiny leaf scars, its shiny brown, straight petiole scales and by its sessile basalmost pinnae.
TYPIFICATION AND SYNONYMY
The holotype at P! has been clearly indicated by Bonaparte (“Original”), but all available original material consists of middle pinnae with rachis fragments necessitating epitypification with a specimen including discriminative characters of the petiole base and trunk. Bonaparte (1917: 29, 30) introduces C. orthogonalis as a nomen nudum and cites “ Baron 2126 ” as the only specimen. Said specimen could not be traced and the citation is most likely erroneous and should be corrected to Baron 6126.
Filix arborescens Cyatheae bellisquamatae affinis sed differt paleis petioli sparsis vel caducis, (0.8-) 2-2.5 cm longis et 0.1- 0.2 cm latis, strictis et nitide brunneis. Pinnulae pro ratione parvae, 1.8(-2.4) cm longae et 0.4(-0.5) cm latae. Praecipue insignis superficie laevi trunci cicatricibus ellipsoideis margine inferiore c. 5 spinis brevibus conicis praeditis.
TYPUS. — Madagascar, Toliara,Tolanaro ( Fort Dauphin ), Eminiminy, Parcelle 1, RNI nº 11 d’Andohahela, versant est et sommet du Trafon’omby, 13.5 km au NW d’Eminiminy, Camp 3, 24°35’40’’S, 46°44’80’’E, 1300 m, 8.XI.1995, Rakotondrainibe 3059 (holo-, P! [2 sheets: P00067163, -64]; iso-, MO!, TAN!) .
ADDITIONAL MATERIAL EXAMINED. — Madagascar. Massif du Beampingaratra, col de Vohipaha, 24°32’S, 46°53’E, 1100-1400 m, 16.XI.1928, Humbert 6642 (K, P) GoogleMaps .
FIELD OBSERVATIONS. — Trunk: HT 5-6 m, DT 6 cm; trunk surface smooth, distantly papillate, dark brown.
Leaf scars: 2 × 4.5 cm, elliptic to obovate; with about five short conical spines on their lower rim and 1-3 shallow orifices below the scar.
Lamina: LL 130 cm, NP 35-40.
Petiole: (20-) 40 cm long, 1.2 cm in diameter when dry; dark reddish brown when fresh, light to dark brown when dry.
Lamina: pinnate-pinnatisect, coriaceous, dark green above, light green below, lamina base shortly attenuate; rachis of the same colour as the petiole, somewhat lighter.
Largest pinnae: 28 cm long, distant by 4-5 cm, adjacent pinnae spaced by less than their width to contiguous, their apex acute, pinnatifid; costae and costulae of the same colour as the rachis.
Largest pinnules: 1.8(-2.4) × 0.4(-0.5) cm, spaced by much less than their width to contiguous, up to 4 proximal pinnule pairs sessile, others broadly adnate to the costa, oblong, slightly falciform, margin entire, but up to 2 proximal pinnule pairs crenate and auriculate, apex rounded to obtuse; veins once, rarely twice furcate.
Scales and hairs:scales present from the petiole base upwards to 15 cm on the petiole, probably further in fresh specimens, moderately dense, overlapping, persistent near the base of the petiole, caducous further up, narrowly triangular, (0.8-)2-2.5 × 0.1- 0.2 cm, straight, concolourous, shiny brown, more or less appressed to the petiole, further up smaller and more or less contorted or with a reflexed apex, not indurated; moderately dense, dark brown, appressed, antrorse multicellular hairs on the adaxial face of the rachis and costae; scattered caducous, appressed, shiny dark brown, narrowly triangular, scales on the abaxial face of the costae; leaf otherwise glabrous.
Sori: sori subcostular, contiguous, less than 0.1 cm in diameter, covering one third to three quarters of the pinnule; indusia globular, brown, membranous, dehiscing irregularly at maturity, but not down to the base of the receptacle; receptacle capitate, shorter or longer than the rim of mature indusia, with inconspicuous short, filiform paraphyses, rudimentary brown sporangiasters on their apex.
Southern Madagascar: Andohahela and Beampingaratra; endemic.
About 1300 m. Dense evergreen rainforests.
The species differs from C. bellisquamata by its smooth trunk surface with elliptical and spiny leaf scars, and sparse or caducous petiole scales. Its pinnules are smaller than in most specimens of C. bellisquamata . It differs from C. approximata by its bigger petiole scales and the absence of scales on the receptacle. Cyathea orthogonalis has conspicuously petiolulate pinnae near the lamina base, dense dull dark brown, contorted scales and usually acute to obtuse pinnules, its leaf scars are not spiny.
Cyathea pseudobellisquamata is furthermore distinguished from C. remotifolia and C. emilei by its coriaceous, subcontiguous pinnules and persistent, shiny brown petiole scales. Petiole scales may rarely persist in C. emilei and C. remotifolia , but are then shorter than in C. pseudobellisquamata . In addition, C. pseudobellisquamata differs from C. emilei by its smooth and spiny trunk surface and from C. remotifolia by its persistent indusia.
Humbert 6642 agrees perfectly with the type specimen with respect to lamina dissection, but its pinnules are bigger, its scales smaller and the trunk is unknown. Th e specimen has been collected in the far Southeast and is morphologically more similar to C. pseudobellisquamata than to all other taxa discussed in this section. The identification of Humbert 6642 as C. pseudobellisquamata must remain ambiguous in the absence of trunk characters and considering the variability of C. bellisquamata .
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