Marsdenia neomicrostoma Meve, Gâteblé & Liede, 2018

Meve, Ulrich, Gâteblé, Gildas & Liede-Schumann, Sigrid, 2018, Two new species from the Ile des Pins (New Caledonia), and a not so new species from Grande Terre (New Caledonia), Phytotaxa 349 (3), pp. 201-213 : 208-212

Marsdenia neomicrostoma Meve, Gâteblé & Liede , sp. nov. ( Fig. 1E, F ; 6 ; 7 )

TYPE: New Caledonia, Grande Terre , Voh, Mt. Katépahié, near 400 m, Jan 20, 1963, H. S. MacKee 10068 (holotype P04222359 , P; isotype NOU057818 , NOU) .

Plants ascending, apically non-twining, to 100 cm high, sparsely branched. Shoots perennial, herbaceous, sparsely covered to densely covered over the whole surface with flexuous trichomes, 300–450 μm long; internodes 35–60 cm long, 1–2 mm diam. Latex white or colorless. Leaves with 5–7 mm long petiole, 3–5 colleters at the base of the leaves; blades coriaceous, discolorous, (4–) 6–8 × 0.2–0.4(–1.5) cm, very narrowly oblong to linear, basally cuneate, apically acute, marginally revolute, glabrous on both sides. Inflorescences always one per node, extra-axillary, sciadioidal, 7–19-flowered, all flowers open synchronously. Peduncles 5–7 mm long, densely covered over the whole surface with flexuous, 450–500 μm long trichomes. Flowers with floral bracts c. 1 mm long, c. 0.3 mm wide at the base, oblong, with trichomes. Pedicels 5–7 mm long, isolatedly to sparsely covered over the whole surface with flexuous, c. 300 μm long trichomes. Floral buds 4–6 × 2–3 mm, cylindrical. Calyx entirely free, ciliate; lobes c. 1.5 × 1.2 mm, ovate, apically obtuse. Corolla urceolate, 4–6 mm long; c. 2 mm diam., white, adaxially with c. 600 μm long trichomes on the throat of the tube and on the lateral parts of the lobes; lobes fused for about half of total corolla length, c. 1 mm wide, incurved to patent, ovate, apically acute, marginally ciliate. Gynostegial corona of free staminal lobes, glabrous, 1–2.5 mm long, shorter than the gynostegium; lobes laminar, broadly oblong to triangular (variable with transition between staminal lobes constituting a small margin and developing a distinct pointed lobe). Gynostegium 1.5–1.7 mm high, 1.5–1.7 mm diam., elevated by a column of c. 300 μm length; anthers broader than high, trapezoidal, abaxially planar, forming a basal arch; anther wings c. 600 μm long, convergent, extending along the whole length of the anther, consisting of distal and proximal ridge, with space between distal and proximal ridge bristly; anther wings of adjacent anthers parallel to each other, in the same plane as the anther; connective appendages 550–600 × 400–450 μm, triangular, narrower than the stamen, strongly inflexed. Pollinarium: corpusculum c. 350 × 150 μm, elliptic, margins of the corpuscular cleft centrally widened; caudicles c. 125 μm long, (sub-)basally inserted at the corpusculum, cylindrical, concavely recurved; pollinia subapically attached to the caudicles, erect, c. 375 × 150 μm, ovate in cross-section, oblongoid. Style-head 0.8–0.9 mm long, 0.9–1 mm diam.; upper part c. 0.5 mm long, longer than the lower part, depressed-conical. Follicles 45–55 × 5–7 mm, obclavate, round in cross-section, apically shortly beaked, wingless, light brown, longitudinally grooved, glabrous, with thin pericarp. Seeds 6–7 × c. 4 mm, pyriform, dark brown, smooth on both sides, marginally with 0.5–0.7 mm wide wing with entire margin; coma c. 20 mm long.

Distribution and habitat: New Caledonia, North Prov. (Grande Terre, Ile Art, Yandé). In maquis to low forests, usually on serpentine sites at the base of northwest ultramafic massifs. Altitude: 10– 600 m.

Phenology: Flowers: October to May. Fruits: December to February.

Etymology.The epithet “ neomicrostoma ” indicates that the species comprises elements often named M.microstoma in previous classifications. “Micro” (very small) and “stoma” (mouth) refer to the limited access to the corolla tube via a very small central opening of the urceolate corolla ( Fig. 1F ).

Vernacular name: Thiknova (Témala), fide Guillaumin & Haudricourt (1961).

Provisional IUCN status: The northwest pattern of distribution at low to medium altitudes on ultramafic (mainly serpentine) substrate between Poya in the south and Art Island in the north is a quite common one. For most low altitude populations, nickel mining is not the main threat but bush fires are the main issue for conservation of plants in those localities. With much more than ten localities, we are assigning a preliminary IUCN conservation status of «Least Concern» using Red List criteria ( IUCN, 2017).

Remarks: Most specimens of this species were hitherto filed under M. microstoma Schltr. (Bot. Jahrb. Syst. 39: 247. 1906. Type: Süd-Bezirk, am Ngoye, Oct 1902, Schlechter 15171 (holo-, probably destroyed in B). In his protologue, Schlechter (1906) names M. billardierei ( Decaisne 1844: 615) as the closest relative of M. microstoma , but does not give any details in which characters the two species differ. In his work on New Caledonian species, Moore (1921) described a new species, M. assimulata ( Moore 1921: 367) , which he placed (in foliage description in the protologue) as the counterparts of M. microstoma and M. billardierei but without having seen any of the type specimens. Later, Guillaumin (1927 publ. 1928, 1948) informally placed M. assimulata under synonymy of M. billardierei without having seen the type of M. assimulata either. He identified specimens (e.g. 1927 publ.1928, 1933, 1934, 1944, 1964) from the northwest and from the south of Grande Terre alternatively to M. billardierei or to M. microstoma with a tendency to assign southern specimens more frequently to M. billardierei and northwestern specimens to M. microstoma . Däniker (1933) also identified his own specimens from the south (Tontouta, Humboldt, Plaine des Lacs) and from the north (Koniambo, Yandé) as M. microstoma though he might have had the chance to see the type specimen of M. microstoma in B before it was destroyed. In general, M. microstoma was most commonly used to designate specimens from the northwestern Grande Terre and the absence of the type specimen probably explains this confusion. However, with the type of M. microstoma coming from the southeast Grande Terre in the N’Goye region (fide Schlechter 1906), it certainly doesn’t match the northwest specimens of M. neomicrostoma that have all been collected between Poya and Belep islands. Should material of Schlechter 15171 —or even another specimen assigned to M. microstoma by Schlechter himself—will be found again, M. microstoma might have priority over either M. assimulata or the recently described M. mackeeorum (Meve, Gâteblé & Liede 2017: 60) , another southeastern species, which differs from M. neomicrostoma mainly by the bostrychoid inflorescences, but also by its long-ascending connective appendages, tiny caudicles and a conical style-head.

M. neomicrostoma is characterized (against M. mackeeorum ) by sciadioidal inflorescences, a short style-head and broad caudicles. Against M. oubatchensis (Schlecthter 1906: 248) , the revolute leaf margins are the best distinguishing character.

Paratypic material:

Koniambo, Feb 26, 2007, Barrière (leg. Ducousso) 80, ( NOU016904 , NOU) ; Mt. Poum , 412 m, Apr 10, 1968 Bernardi 12659 ( P04222317 , P) ; Sentier entre Tiébaghi et Néhoué , Jan 20, 1965 Blanchon 1393, ( NOU057823 , NOU) ; Belep Art, Dec 1978 Bourret 1928, ( NOU057779 , NOU). Paagoumène, base Nord-Ouest du dôme, Jan 20, 2004 Dagostini et al. 741 ( NOU002859 , NOU). Tanlé, Nené, 1861–67, Deplanche 468 ( P04222368 , P04222369 , P) ; s.loc., 1861- 67 ( P04222370 , P), Deplanche 468, Tanlé, 1867, Deplanche 468 (Mus. Cal. 120), ( P04222375 , P) ; s.loc., 1861, Deplanche s.n., ( P04222372 , P) ; Yandé, Apr 07, 1924, Däniker 177b (Z-000052740, Z) ; am Piton Pandop und am Fuss des Kaala Koumac , Feb 20, 1925, Däniker 1321 (Z-000052735, Z-000052737, Z-000052738, Z) ; Ile Art, May 08, 1925 Däniker 3111 (Z-000052750, Z) ; Tinip , 100 m, Apr 26, 2016 ( NOU) ; 895, Pairomé , Ile Art, 70 m, Apr 26, 2017, Gâteblé 762 ( NOU) ; Ile Art, Plateau Nord, Dec 09, 1975, Jaffré 1527 ( NOU017848 , NOU; P04222366 , P) ; Mt. Kaféaté , 30–100 m, Mar 30, 1956, MacKee 4221 ( P04222367 , P) ; base de Mt. Kaala ; près de Gomen, 100 m, Dec 30, 1964, MacKee 11895 ( P04222357 , P) ; Montagne de Poum , 400 m, Feb 01, 1966, MacKee 14345 ( P04222358 , P) ; Pente nord de Mt. Kaala, 700 m, Dec 25, 1966, MacKee 16157, ( NOU057817 , NOU; P04222355 , P) ; Oundjo , 10 m, Apr 23, 1967, MacKee 16672 ( P04222361 , P) ; Mt. Koniambo , Plateau sommital, 800–850 m, May 21, 1967, MacKee 16802 ( P04258745 , P) ; Cap Tonnerre , 0–30 m, Feb 04, 1968, MacKee 18355 ( P04222356 , P) ; Paagoumène , 30 m, Feb 27, 1970, MacKee 21656, ( NOU057816 , NOU; P04222353 , P) ; Mt. Yandé , pente ouest, 200 m, Oct 07, 1970, MacKee 22683 ( NOU057835 , NOU; P04222354 , P) ; Titch , 20–100 m, Jan 05, 1971, MacKee 23143 ( NOU057820 , NOU; P04222350 , P) ; Oundjo , 0–50 m, Feb 17, 1972, Mackee 25046 ( P04222351 , P) ; Mt. Koniambo , pente sudouest, 400 m, Apr 24, 1974, MacKee 28550,( P04222347 , P) ; Pouembout : Plateau Tiéa, 400 m, Jan 01, 1977 MacKee 32576 ( P04222346 , P) ; Pouembout : Embouchure de la Tiaoué, Dec 30, 1977, MacKee 34480 ( NOU017840 , NOU; P04222343 , P) ; Koumac : Siounda, 30 m, May 13, 1978, MacKee 35140 ( NOU017849 , NOU; P04222344 , P) ; Mt. Ouazangou (base sud), 100 m, Jan 22, 1979, MacKee 36464 ( NOU017841 , NOU; P04222339 , P) ; Mt. Kaala , 300 m, Mar 27, 1980, MacKee 37965 ( NOU057775 , NOU; P04222341 , P) ; Tinip , 30 m, Dec 21, 1981, MacKee 40125 ( NOU057824 , NOU; P04222338 , P) ; Tinip river , near Ouaco, north of Voh, c. 100 m, Jan 08, 1983, McPherson 5363, (MO-2253122, MO; P04222362 , P) ; Base du Kaala, ancienne piste, Jan 29, 1999, Munzinger 383 ( P00246816 , P) ;, Tiéa, Jan 10, 2004, Munzinger 1893 ( NOU012996 , NOU) ; Tanlé, Pancher s.n. (Mus. Néocol. 120, Vieillard 984) ( P04222371 , P04237247 , P) ; Base du Mont Katépahié, Mar 23, 1982, Suprin 1724 ( NOU057821 , NOU) ; 10 km S of Pouembout , Oct 26, 1959, Thorne 28261 ( P04237248 , P) ; Mt. Katépahié , Jul 28, 2014, Vandrot 928(right) ( NOU083913 , NOU) ; Montagne de Poum , pic 272, 25 Mar 1982, Veillon 4846 ( NOU057815 , NOU; P04593779 , P) ; Gatope (Tanlé), 1861-67; Vieillard 984bis (Deplanche 128) ( P04222376 , P) ; «Balade», 1855–60, Vieillard 984, ( P04258639 ) ;, Tanlé, 1861-67, Vieillard 984bis (Deplanche 468) ( P04222377 , P) ; Gatope, 1861–67, Vieillard 2992 ( P04237239 , P) ; Gatope, montagnes (Néné), 1861–67, Vieillard 3004 ( P04237240 , P) ; Mt. Kaala , base versant Ouest, c. 20 m, Nov 07, 1943, Virot 1397 ( P04237235 , P04237236 , P) .

POSSIBLY ALSO:

Mt. Koniambo , 400–800 m, Mar 31, 1956, MacKee 4272, ( P04258751 , P)—fruits only ; Mt. Kaala , 100 m, Jun 12, 1965, MacKee 12754, ( P04222325 , P)—fruits only ; Crête au sud de Ouaté, 500–800 m, Aug 28, 1967, MacKee 17395, ( P04258737 , P)—fruits only ; Mt. Kaféaté , Apr 19, 1977, MacKee 33104, ( NOU057836 , NOU; P05031666 , P)— sterile .

Figures

FIGURE 1. A, B, Heterostemma bicanthaceum (A, Ile des Pins, Sentier Oro-Upi, 20-04-16, GG756, photo: G. Gâteblé; B, Ile des Pins, 20-04-2016, photo: C. Laudereau). C, D, Marsdenia kuniensis (C, Ile des Pins, Sentier Oro-Upi, 20 Apr 2016, GG754). E, F, Marsdenia neomicrostoma (Grande Terre, Tinip, 08 Mar 2007). (Photo: A,C, E–F: G. Gâteblé; B, D: C. Laudereau).

FIGURE 6. Marsdenia neomicrostoma Meve, Gâteblé & Liede. A, branch with inflorescences and open follicle; B, leaf in cross-section; C, flower in lateral view; D, flower in lateral view, the three proximal corolla lobes removed to show the gynostegium; E, corolla, three flattened lobes in adaxial view; F, gynostegium; G, anther adaxial view and lateral view with corona; H, pollinarium; I, style-head, J, seed, aseta side: A, J from MacKee 22683; B–I, MacKee 16157 (Drawn by U.Frensch).

FIGURE 7. Distribution of Marsdenia neomicrostoma Meve, Gâteblé & Liede.