Melanoxerus suavissimus (Homolle ex Cavaco) Kainul. & B. Bremer

Kainulainen, Kent, 2021, A taxonomic revision of Melanoxerus (Rubiaceae), with descriptions of three new species of trees from Madagascar, Candollea 76 (1), pp. 105-116 : 114-115

4. Melanoxerus suavissimus (Homolle ex Cavaco) Kainul. & B. Bremer ( Fig. 5 ).

 Gardenia suavissima Homolle ex Cavaco in Adansonia ser. 2, 7: 177. 1967.  Euclinia suavissima (Homolle ex Cavaco) J.-F. Leroy in Adansonia ser. 2, 14: 52. 1974.

Holotypus: MADAGASCAR. Reg. Androy [Prov. Toliara]: Ambovombe, 27.X.1924, Decary 3357 ( P [ P00852562 ]!) .

Shrubs or trees up to 13 m tall and 40 cm dbh, with mostly sympodial branching. Bark (mottled) whitish or pale grey to pale brown, smooth, flaky. Stipules 3–10 × 2–4 mm, triangular, interpetiolar, caducous. Leaves deciduous, petioles 0.5–5 cm long, adaxially canaliculate; leaf blades papyraceous, ovate to lanceolate, 6.5–16 × 2–9(–11) cm; bases (rounded) cuneate to attenuate (often asymmetrically); apices acute to acuminate; adaxial surface dark green when fresh, drying dark brown to black, smooth, matte or glossy, ± glabrous to (velvety) pubescent in particular along midrib and venation; (6–)8–10(–12) pairs of conspicuous, ± pinnate secondary veins, tertiary venation reticulate; midribs prominent, pale green when fresh, ± the same colour as the leaf when dry; abaxial surface pale green when fresh, drying dark brown to blackish, matte or glossy, ± glabrous or with pubescent midrib and venation, tuft domatia often present in the vein axils. Flowers solitary, terminal, very fragrant; pedicels up to 9 mm long; hypanthium narrowly urceolate, 4.5–12 × 2.5–5.5 mm, glabrous; calyces green; calyx tubes 1–5.5 mm long, externally and internally glabrous; calyx lobes 4.5–8 × 1–3 mm, narrowly ovate, acuminate, recurved; corollas fleshy, funnelform, straight; corolla tubes 2–4.5 cm long, externally white to pale yellow often with a greenish base, glabrous, internally white with pink, red, or purple spots, finely pubescent (trichomes 0.5–1.5 mm long). Corollas lobes white (sometimes pale yellow on the external side), 2–4.5 × 1–3 cm, ovate, acute, spreading horizontally at anthesis; stamens subsessile (filaments c. 1 mm long), attached 10–14 mm below corolla sinus and 6–10 mm from anther base; anthers 22–26 × 1.5–2 mm, linear, exserted for c. 5 mm. Styles simple, clavate, with shallow longitudinal grooves, to c. 5 cm long, glabrous, usually shortly exserted for c. 5 mm; stigma shortly bifid (lobes c. 5 mm long). Fruits globose to ellipsoid, 3–5 × 2.5–3.5 cm, smooth, glabrous, olive to grey brown or dark purple to black with numerous beige to pale grey lenticels (0.1–1 mm in diam.), fleshy-indehiscent; calyx tube usually persistent, but lobes caducous. Seeds flattened, irregularly angled, 7–10 mm in diam., c. 2 mm thick, smooth, yellowish brown when fresh, drying black.

Vernacular names. – “Asomitsoy” (Rakotonasolo et al. RNF 932); “Hazomfotaka” (Réserves Naturelles 6762); “Kaliona” (Koechlin s.n.); “Mahabiboala” (Service Forestier 29830); “Vala” (Service Forestier 5797); “Voafotaka” (Decary 4556); “Volatsiva” (Service Forestier 4136).

Distribution, habitat and ecology. – Melanoxerus suavissimus is widespread in subarid vegetation in the Androy, Anosy, Atsimo-Andrefana, and Menabe Regions (Toliara Province), and occurs as far north as the Manambolo river in the southernmost part of the Melaky Region (Mahajanga Province) ( Fig. 1 ). It is found from sea level to c. 800 m in elevation.

Phenology. – Flowering specimens have been collected in (April) July to December, and fruiting specimens throughout the year.

Conservation status. – Melanoxerus suavissimus is widespread in south-western Madagascar and has been assigned an IUCN conservation status of “Least Concern” [LC] ( IUCN, 2021).

Notes. – Since CAVACO’S (1967) original description of Melanoxerus suavissimus (as Gardenia suavissima ) included specimens of both M. atropurpureus and M. maritimus , an amended description is provided.

This is the most widespread and the most commonly collected species. However, few collections have been made in from May to August (none from June), and presumably this species is usually leafless during that time. Melanoxerus suavissimus usually flowers at the same time or just before the new leaves flush (cf. Fig. 5A, D ). Apparently, the juice of the fruits turns black and is used for making tattoos ( SCHATZ, 2001). Information about of the use of Melanoxerus by local people is otherwise scant, although according to the label information on the specimen Ranaivojaona et al. 248, the fruits are edible.

Selected additional material examined. – MADAGASCAR. Reg. Androy [Prov. Toliara]: Besakoa , 24°56'36"S 45°27 '59"E, 227 m, 4.III.2003, fr., Andriamahay 497 ( K) ; Imanombo , XI.1952, fr., Bosser 3787 ( P) ; Beraketa , X.1956, fl., Bosser 10237 ( P) ; Ambovombe , XII.1959, fl. & fr., Bosser 13353 ( P, TAN) ; Beraketa, on road to Isoanala, 10 km S of Soanala, 646 m, 19.XII.2004, fr., Rakotonasolo et al. RNF 932 ( K, TAN) ; Antanimora , 30.VII.1926, fr., Decary 4556 ( P) ; Behara , 22.X.1954, fl., Réserves Naturelles 6762 ( P) ; Ampandrandava , 700–800 m, X.1942, fl., Seyrig 122 ( P) ; Beloha , 19.II.1949, fr., Service Forestier 454 ( P, TEF) ; Imanombo-Ifotaka (rte), 26.IX.1952, fr., Service Forestier 5797 ( P, TEF) . Reg. Anosy [Prov. Toliara]: Distr. Amboasary Sud, Marotsiraka , Atsonjo Analamainty , Ankotsy , 24°17'44"S 46°07'43"E, 453 m, 10.XI.2008, fr., Andriamihajarivo et al. 1527 ( G, MO) ; Anadabolava , 200–250 m, XII.1933, fr., Humbert 12450 ( P) ; Andohahela, Ihazofotsy , 24°50'S 46°32'E, 100 m, 16.IV.1996, fr., Laha 75 ( BR, G, K, MO) ; Fort Dauphin, Analamatahitra , 31.I.1952, fr., Service Forestier 4463 ( P, TEF) ; Fort Dauphin, Anteviala , 10.IV.1960, fr., Service Forestier 10789 ( P, TEF) . Reg. Atsimo-Andrefana [Prov. Toliara]: Distr. Sakaraha, forêt d’Analaraty , 22°49'14"S 44°17'16"E, 520 m, 20.XII.2010, fr., Andriamihajarivo et al. 1814 ( MO, P, TAN) ; Zombitse, lieu dit Poakafo , 22°46'21"S 44°40'25"E, 540 m, 8.IV.2006, fr., Andriamihajarivo et al. 905 ( MO, TAN) ; Befandriana-Sud , 150 m, 9.IX.1961, fl. & fr., Appert 203 ( MO, Z) ; along rte #10 between Betioky and Ejeda, 175–225 m, 14.II.1975, fr., Croat 31241 ( MO, TAN) ; St. Augustin , 23°28'58"S 43°45'58"E, 0 m, 6.I.1999, fr., De Block et al. 561 ( BR, K, MO, P, TAN) ; road from Betioky to Ampanihy, c. 23 km after Ejeda, 24°31' 17"S 44°37'25"E, 244 m, 6.II.2007, fr., De Block et al. 2323 ( BR, MO, P, S, TAN, WAG) ; entre Tongobory et aux environs d’Ambovombe, 117–214 m, 20.I.2004, fr., Hong-Wa et al. 178 ( G, MO) ; forêt de Besomaty entre le Fiherenana et l’Isahaina ( Mangoky ), 750–800 m, X.1933, fl., Humbert 11250 ( P) ; Manombo, Fiherenamasay , 18.XI.1967, fl., Koechlin s.n. ( P) ; St. Augustin , 23°27'S 43°46’ E, 10 m, 1.II.1990, fr., Labat & Du Puy 2045 ( K, MO, P) ; vallée du Fiharenana , 0–200 m, 9.XI.1960, fl. & fr., Leandri 3778 ( P) ; lac Tsimanampetsotsa , 0 –100 m, 23.XI.1960, fr., Leandri & Saboureau 4451 ( BR, K, P) ; 20–30 km N of Tulear on the road to Morombe, 23°12'S 43°37'E, 5–10 m, 11.XI.1989, fl. & fr., Miller & Keating 4513 ( K, MO, P, TAN) ; rte d’Ankazoabo , II.1967, fr., Morat 2455 ( P, TAN) ; vallée de Fiherenana , X.1924, fl., Perrier de la Bathie 16653 ( P) ; Beza Mahafaly Reserve near Betioky, 23°40'S 44°35'E, 160 m, 17.V.1987, fr., Phillipson 1812 ( MO) ; ibid. loco, 23°40'S 44°38'E, 150 m, 20.X.1987, fl., Phillipson 2413 ( K, MO, P, TAN) ; ibid. loco, 23°41'S 44°39' E, 160 m, 13.XI.1987, fr., Phillipson 2558 ( K, MO, P, TAN) ; Itampolo, Montagne de Haktokaliotse , 24°24'26"S 43°51'01"E, 100 m, 1.IX.1998, fr., Rakotomalaza & Messmer 1653 ( G, K) ; Ambohimahavelona, Sept Lacs, Andranolahy , 23°31'32"S 44°09'27"E, 100 m, 15.IX.1998, fl., Rakotomalaza & Messmer 1725 ( G, K) ; Manombo , near PK 32, 23°03'00"S 43°41'42"E, 9.XII.2004, fr., Rakotonasolo et al. RNF 880 ( BR, K, MO, TAN) ; Basibasy, Mikea forest , 22°10'13"S 43°31'30"E, 100 m, 31.I.2000, fr., Ranaivojaona et al. 248 ( G, K, MO) ; Belalanda, Ranobe , 22°56'49"S 43°41'08"E, 135 m, 15.III.2006, fr., Ranaivojaona et al. 1425 ( P) ; ibid. loco, 22°58'04"S 43°40'22"E, 108 m, 5.IX.2006, fl., Ranaivojaona et al. 1456 ( G, K, MO, P) ; Sakaraha, Mahaboboka, Ambinanintelo , Forêt de Satra , 22°48'10"S 44°17'54"E, 470 m, 23.III.2013, fr., Randrianarivony et al. 570 ( MO, P) ; Zombitse-Vohibasia NP, Isako , 22°41'S 44°50’ E, 4.XII.2003, ster., Razafimandimbison & Bremer 496 ( MO, TAN, UPS) ; Beroroha, Antsoa, Androtsy forest , 21°05'43"S 45°05'48"E, 254 m, 9.I.2011, fr., Razakamalala 5851 ( MO) ; Imonty, Ankazoabo, Sakaraha , 27.XI.1951, fr., Service Forestier 4136 ( P, TAN, TEF) ; Antseva, Besifake , 500 m, 11.II.1955, fr., Service Forestier 12815 ( P, MO, TEF) ; Sarodrano , XII.1961, fl., Service Forestier 20830 ( BR, K, MO, P, TEF) . Reg. Melaky [Prov. Mahajanga]: Tsingy de Bemaraha , 19°09'S 44°49'E, 50 m, 10.XII.1996, fr., Jongkind et al. 3482 ( BR, K, L, MO, TAN) . Reg. Menabe [Prov.Toliara]: village avant la Réserve d’Andranomena, 17.X.1999, fl., Allorge 2428 ( P) ; on the road to Belo, c. 68.5 km NE of Morondava, 19°55'06"S 44°36'00"E, 5 m, 22.II.2000, fr., Davis et al. 2587 ( BR, K, MO, TAN) ; Kirindy Mitea NP, 20°53'14"S 43°55'22"E, 20 m, 21.III.2011, fr., Razafimandimbison & Kainulainen 1205 ( MO, S) ; N de Tsimafana env. 2 km, 25.V.1980, fr., Service Forestier 29830 ( TEF) .

Figures

Fig. 5. – Melanoxerus suavissimus (Homolle ex Cavaco) Kainul.& B. Bremer. A. Habit and habitat; B. Top view of the flower; C. Flower; D. Flowering branch; E–F. Immature fruits. [A–B: Ranaivojaona et al. 1456; D: Phillipson 2413; E–F: Andriamihajarivo et al. 1814] [Photos: A–B, D–E: P. Phillipson; C: S. Landrein, Ifaty (Toliara), 5.X.2006; F: K. Kainulainen]

Fig.1.– Distribution of Melanoxerus antsirananensis Kainul. (yellow circles), M. atropurpureus Kainul. (pink circles), M. maritimus Kainul. (triangles), and M. suavissimus (Homolle ex Cavaco) Kainul. & B. Bremer (stars) in Madagascar.[mapped on the bioclimatic zones of Madagascar (after CORNET, 1974; see SCHATZ, 2000)]