Atractocarpus heterophyllus (Montrouz.) Guillaumin & Beauvis

Mouly, Arnaud, 2012, On the distinction of Atractocarpus heterophyllus (Montrouz.) Guillaumin & Beauvis. and A. bracteatus Schltr. & K. Krause (Rubiaceae): in search of the correct name for the type species of Atractocarpus Schltr. & K. Krause, Adansonia (3) 34 (1), pp. 103-114 : 110-113

Atractocarpus heterophyllus (Montrouz.) Guillaumin & Beauvis .

( Fig. 3 )

Annales de la Société botanique de Lyon 38: 96 (1913 publ. 1914).

— Basionym: Gardenia heterophylla Montrouz. , Mémoires de l’Académie Royale des Sciences de Lyon, Secteur Sciences 10: 216 (1860).

— Type: New Caledonia. Île Art , 1859, Montrouzier 179 (lecto-, MPU, hicdesignatus). — Previous syntypes: New Caledonia. Île Art , 1859, Montrouzier 94 ( LYJB †). — Île Art , 1859, Montrouzier 95 ( LYJB †).

Atractocarpus balansaeanus Baill. ex Guillaumin , Archives de Botanique, Mémoire 3 (5): 12 (1930).

— Type: New Caledonia. Île Yandé, fr., 23.VI.1871, Balansa 3212 (lecto-, P, hic designatus ; isolecto-, P). — Previous syntype: New Caledonia. “ Rade de Canala , sur les rochers maritimes” (doubtful locality, see note below), fr., 29.VI.1869, Balansa 2012 ( P).

O THER SPECIMENS EXAMINATED. — New Caledonia. Mt Yandé, fr., 23.VIII.1978, Cabalion 644 ( P). — Insel Yande, fl., 7.IV.1925, Däniker 1574 ( P). — Vallée de Voh sup. 250 m, 12.IV.1951, Guillaumin & Baumann-Bodenheim 12122 ( P). — Boulinda 200 m, fr., 1.VII.1972, Jaffré 844 ( NOU, P). — Base du Massif du Boulinda, fr., 8.VII.1975, Jaffré 1346 ( NOU) ; idem, Jaffré 1352 ( NOU). — Île Pott , Panan, 10-60 m, fr., 29 Jul1968, MacKee 19355 ( NOU, P). — Île Yandé, fl. fr., 6.X.1970, MacKee 22621 ( NOU). — Népoui, presqu’île de Muéo, fl., 10.XII.1970, MacKee 22997 ( NOU, P). — Baaba, secteur S.O., fr., 6.I.1971, MacKee 23194 ( NOU). — Plateau de Tiéa , pente Nord, maquis sur terrain rocheux serpentineux, 200-300 m, fr., 2.XI.1971, MacKee 24536 ( P). — Amos, fl., 4.XII.1972, MacKee 26041 ( NOU). — Gomen , Ouéholle, maquis sur pente serpentineuse, 300 m, fl., 28.XII.1972, MacKee 26124 ( P). — Col d’Arama , versant Ouest, maquis ouvert sur terrain serpentineux, 80 m, fr., 23.III.1973, MacKee 26464 ( P). — Kopéto, crête est du Mt Vert, maquis haut sur pente raide rocheuse serpentineuse, 700 m, fr., 24. VI.1973, MacKee 26888 ( P). — Vallée de Poya , Ndokoa, maquis sur terrain rocheux serpentineux, 100 m, fr., 31.X.1973, MacKee 27703 ( P). — Poya , Avangui, 300 m, fl., 2. I.1976, MacKee 30611 ( NOU, P). — Poindimié , Povila, forêt dense basse, terrain serpentineux rocheux, 200 m, fr., 13.IX.1976, MacKee 31522 ( P). — Poya , Nékoro, 200 m, fr., 21. V.1977, MacKee 33208 ( NOU, P). — Paagoumène, maquis haut sur terrain serpentineux, 10 m, fl., 6.II.1980, MacKee 37809 ( P). — Poya , Ndokoa, fr., 11.VII.1981, MacKee 39214 ( NOU, P). — Dent de Poya, 500 m, fr., 17.IX.1981, MacKee 39569 ( NOU, P). — Poya, restes de forêt sur alluvions, 40 m, fl., 1.XII.1990, MacKee (leg. Cherrier) 45197 ( P). — Poya , restes de forêt sur alluvions, 40 m, fr., 1.XII.1990, MacKee (leg. Cherrier) 45202 ( P). — Île Yandé , fr., 23.VIII.1978, Morat 6131 ( NOU). — Province Nord , Poya, Nétéa, le long du creek, 50-150 m, fr., 8. VI.2007, Mouly & Barrabé 850 ( BR, K, NOU, P). — Île Yandé , face Est, 200 m, fr., 5.X.2005, Munzinger & Swenson 3037 ( NOU, P). — Poya , Nétéa, 21°15’6’’S., 165°11’27’’E., fr., 3.III.2007, Munzinger 4190 ( NOU). — Gorges de N’Dokoa , Poya, fr., 20.X.1974, Sévenet 731 ( P). — Île Yandé , N.O., fr., 23.VIII.1978, Veillon 3657 ( NOU, P). — Montagnes de Balade, fl., 1855-1860, Vieillard 649 ( P). — Wagap, 1861-1867, Vieillard 2752 ( P).

DESCRIPTION

Dioecious, small slender tree 1-2.5 m high, monocaul, or few stemmed. Stipules paired, imbricate, lanceolate, 12-15 × 3-4 mm.Leaves opposite, of nonflowering shoots oblong-elliptic, glabrous; petioles 26-42 mm long; lamina 140-220 × 50-100 mm, apex acuminate, base rounded, glossy dark green, dull grey-green below, coriaceous; secondary veins 5-10 pairs at 55-65° to the midvein. Inflorescences axillary, branch-like to 140 mm long, consisting of 2 internodes, flowers arranged in cymes, 3-florous in male, and solitary in female individuals; flowers ± sessile, 5-merous, with a slight sexual differentiation, flowers substended by modified leaves, cordate, 20- 45 mm long. Hypanthium 9-10 mm long and linear in male, 11-14 × 3-5 × 3-5 mm, centrally inflated in female individuals. Calyx tube obconical, 2-3 mm long; lobes triangular, 1.5-2 mm long. Corolla tube c. 20 mm long, urceolate, c. 4 mm diameter at the widest point, glabrescent outside, glabrous inside, except where it is bearded below the anthers.Corolla lobes lanceolate, c. 15 × 7-10 mm, glabrous.Anthers bilocular, 7-10 mm long, dorsifixed, supramedifixed, attached 4-5 mm from their apices, subsessile,inserted 5-6 mm below the sinuses of the corolla lobes. Style included, c. 19 mm long; stigmatic lobes 2, c. 7 mm long. Ovary bilocular, elongate, c. 8 × 2 × 2 mm, placentation axile, each bearing many ovules. Fruit solitary, oblong-ovoid, 30-60 × 25-50 mm, smooth narrowing towards the calyx tube; exocarp smooth, green when mature; placentas extending in a whitish pulp. Seeds c. 4 × 4 × 0.5 mm; hilum occupying c. 0.5 mm of the perimeter of seed; exotesta cells with a thickened ring around the inner tangential wall and occasional interstitial thickenings.

NOTE ON TYPIFICATIONS

Since Montrouzier never cited the original material in his Flora, possible syntypes are accepted from citations in Guillaumin & Beauvisage (1913). As two of the three syntypes of A. heterophyllus (Montrouzier 94, 95) have been destroyed in LYJB, only one Montrouzier’s gathering (Montrouzier 179) remains available at MPU. Though without any annotation from Montrouzier as an author, the MPU gathering cannot be rejected as original material, being in agreement with the protologue and collected before the publication of the protologue. The collection Montrouzier 179 is thus designated here as lectotype for A. heterophyllus .

The lectotype of Atractocarpus balansaeanus was chosen from two original gatherings cited by Guillaumin (1930). The collection Balansa 3212, designated as lectotype, is well preserved and representative of the protologue. The other syntype collection Balansa 2012 consists of only one sheet in worse condition than the lectotype.

DISTRIBUTION, ECOLOGY, AND HABITAT Atractocarpus heterophyllus is endemic to northern New Caledonia and Belep Islands ( Fig. 4 ). This species is exclusively riparian, restricted to limestone and serpentine soils, on rocks and rock slides. On the main island, most of specimens collected belong to the western coast populations. The gathering Balansa 2012 bears the label information “Canala” (southeastern coast), a locality poorly reliable for the species. Besides the gathering Balansa 2012, the two old collections made by Vieillard from the east are unclearly localized. Indeed, Vieillard indicated on labels the locality where he was based instead of the locality of the collection. The eastern coast is now well explored, and only one recent collection can be attributed to A. heterophyllus , in the Poindimié area. The few eastern populations are probably smaller and more threatened than the western ones.

Figures

FIG. 3. — Atractocarpus heterophyllus (Montrouz.) Guillaumin & Beauvis.: A, view of the apex of a female individual in fruit; B, detail of stipules at branch apex; C, transversal section of a fruit; D, longitudinal section of a fruit; E, developed placenta at fruit stage, in dorsal and ventral views; F, longitudinal section of a seed; G, embryo. Scale bars: A-E, 3 cm; F, G, 2 mm. Based on MacKee 26464 (P) and unpublished N. Hallé’s drawings of New Caledonian Rubiaceae in sched (P).

FIG. 4. — Distribution map of Atractocarpus bracteatus Schltr. & K.Krause (■) and A. heterophyllus (Montrouz.) Guillaumin & Beauvis. (●) in New Caledonia.