Dicksonia munzingeri Noben & Lehnert, 2013

Noben, Sarah & Lehnert, Marcus, 2013, The genus Dicksonia (Dicksoniaceae) in the western Pacific, Phytotaxa 155 (1), pp. 23-34 : 29-31

Dicksonia munzingeri Noben & Lehnert , sp. nov. ( Figs. 2C , 3C )

Type:— NEW CALEDONIA. Province du Sud: Forêt des Sailles , just before Mount Pwénari, 21°36'58''S, 166°14'49''E, 1200 m, 8 December 2001, J . Munziger, B . Suprin & F . Carriconde 1306 (holotype MO, isotype P) .

The new species Dicksonia munzingeri is most similar to D. thyrsopteroides in the morphology of the lamina, but differs strongly in petiole characters (white to grayish, matted wooly hairs, falling off in flakes and white to brownish undercoat of appressed hairs in D. munzingeri vs. spreading reddish brown, setiform hairs and sooty undercoat in D. thyrsopteroides ).

Trunks to 5 m tall, 12 cm diameter, with persistent petiole bases, frond scars not visible, with a thick layer of adventitious roots to 2 m up the trunk; adventitious buds not observed. Fronds to 350 cm long, almost patent, weakly ascending, stiffly planar; fertile fronds hemidimorphic, basal pinna pair sterile, following ones fertile up to the middle of the laminae; dead fronds persist at the trunk, forming a skirt. Petioles to 60 cm long, covered with a white to brownish undercoat of appressed hairs and white to grayish, matted woolly hairs, falling off in flakes. Petiole hairs ciliform, to 2 cm long at the petiole base, becoming more and more ephemeral in upper parts. Laminae to 290 × 110 cm, tripinnate-pinnatifid with gradually reduced apices, adaxially deep glossy green, abaxially paler, coriaceous. Frond axes [rachises, costae and costules] yellowish in fresh material, light brown in dried material, smooth. Pinnae to 15 pairs per frond, subsessile to sessile, the lowest pair patent to weakly reflexed; sterile pinnae to 60 × 22.5 cm, ovate-lanceolate, fertile pinnae to 43 × 16.5 cm, lanceolate, bases truncate to rounded. Sterile pinnules to 11.6 × 2.3 cm, lanceolate, auriculate, subsessile, sometimes slightly stalked at the base of the pinnae, becoming more sessile towards the tip. Fertile pinnules to 8.5 × 1.8 cm, elongate-lanceolate, subsessile to slightly stalked at the very base of the pinnae. Fertile segments reduced to thin strands along the veins, subsessile to sessile. Sterile segments weakly lobed or dissected, sessile, margins serrate. Indument consisting of multicellular, ciliate hairs, completely whitish or bicoloured with brown tips, relatively stiff, antrorse and persistent. Costae and costules abaxially hairy, woolly and glabrescent, becoming more and more spreading and persistent from costae to midveins; lateral veins usually lacking hairs on both sides. Sori 1.6–2.0 mm wide, marginal, at the end of unbranched lateral veins, oblong to slightly kidney shaped when closed, circular when open; indusia bivalved, outer one greenish to dark brown, with a thin cartilaginous margin, inner one light brown or pale green with subentire to weakly lacerate margins; paraphyses of the same length as or longer than sporangia. Spores not examined.

Distribution and habitat: —Restricted to central New Caledonia (Massif de Tchingou to Forêt de Saille, with an outlier at the Rivière Bleue), in dense mountain rainforest at (200–) 1000–1260 m.

Etymology: —Dedicated to Jérôme Munzinger (Institut de Recherche pour le Développement, Marseille, France), who collected the type specimens, in recognition of his contributions to the knowledge of the New Caledonian flora.

Paratypes: — NEW CALEDONIA. Province du Nord: Massif de Tchingou , 20°53'94''S, 165°00'45''E, 1260 m, 4 April 2001, J . Munzinger & G . McPherson 672 ( MO, P); Mont Aoupinié , 21°10'35''S, 165°16'03''E, 1000 m, 3 Oktober 2009, J . Munzinger et al. 5949 ( MO, NOU n.v., P). Province du Sud: Mount Ningua , forest beside road, before Virgin Pass ["forest of the different trees"], 21°44'44''S, 166°09'19''E, 1080 m, 29 September 2012, L . Perrie NC2012-77 ( NOU, WELT) .

Additional specimens examined (digitalized): — NEW CALEDONIA. Province du Sud: Dogny, 600 m, 28 October 2007, J . Munziger et al. 4620 ( NOU); “Col Amieux” [= Col d’Amieu , ca. 21°37'S, 165°47'E], Juli 1907, A . Le Rat 3 ( P); Rivière Bleue , borde de la piste a la tranchée, 22°08'S, 166°42'E, 200 m, 1 June 1994, J.- C . Pintaud 56 ( P); “ Ninga ”[= Mont Ningua], versant NE , [ca. 21°44'44''S, 166°09'19''E,] 1200 m, 8 July 1972, J. M . Viellon 2612 ( NOU); Massif de la Ouenghi [= Kuenthio , near Pic de Ningua?], ca. 1000 m, 4 April 1969, M . Schmid 2811 ( MO, P) .

Discussion: — Dicksonia munzingeri was included in D. thyrsopteroides because of shared morphological characters of the lamina (e.g., the hemidimorphism of fronds, the sessile pinnae and the reduction of fertile segments). However, D. munzingeri differs in the persistence of dead fronds on the trunk that build a skirt (vs. only bases persistent in D. thyrsopteroides ), the form of hemidimorphism (lowest and upper pinnae sterile, central fertile in D. thyrsopteroides vs. only the lowest pinnae sterile in D. munzingeri ), as well as the characteristics of the petiole, with its whitish matted, woolly hairs (vs. spreading to appressed, reddish to pale brown setiform hairs in D. thyrsopteroides ) and the lack of a sooty undercoat. Furthermore, D. munzingeri retains a line of matted hairs abaxially along the costae (vs. glabrescent with few persistent spreading hairs).

Dicksonia munzingeri is found together with D. baudouinii on Mont Ningua, with both species occurring in large numbers (L. Perrie, personal communication).

Figures

FIGURE 2. Morphological features of New Caledonian Dicksonia species: First row (1) sterile (A, C & D) or intermediate segments (B), abaxially; second row (2) fertile segments, adaxially; third row (3) petioles. A. Dicksonia baudouinii. B. Dicksonia perriei, sp. nov. C. Dicksonia munzingeri, sp. nov. D. Dicksonia thyrsopteroides.

FIGURE 3. Morphological features of New Caledonian Dicksonia species: sterile pinnules, adaxially A. Dicksonia baudouinii. B. Dicksonia perriei, sp. nov. C. Dicksonia munzingeri, sp. nov. D. Dicksonia thyrsopteroides.