Syzygium jambos ( Linnaeus 1753: 470 ) Alston (1931: 6)

Byng, James W., Barthelat, Fabien, Snow, Neil & Bernardini, Benedetta, 2016, Revision of Eugenia and Syzygium (Myrtaceae) from the Comoros archipelago, Phytotaxa 252 (3), pp. 163-184 : 179-180

5. Syzygium jambos ( Linnaeus 1753: 470) Alston (1931: 6)

For synonyms see WCSP (2015).

Trees 7– 15 m. Branchlets terete, 2–3 mm diameter, brownish. Petioles 3–10 mm. Blade ca. 8–20 × 1.3–5.5 cm, lanceolate or elliptic; base cuneate, apex acute to acuminate; secondary vein pairs 12–20; intramarginal vein ca. 0.5 mm from margins. Inflorescences terminal, cymose, 1–5-flowered. Flowers ca. 4.5–5 cm in diameter at anthesis, pedicel ca. 1 cm, pseudostalk 5–10 mm. Hypanthium 10–20 × 7–10 mm, pyriform, green to white. Calyx lobes ca. 1 × 1 mm, triangular. Petals 10–20 × 6–15 mm, free, semi-orbicular. Stamens 2.5–4 cm long, white to yellowish. Style 3.5–4 cm long. Fruits ca. 5 cm long, globose or ellipsoid, white, yellow or pinkish at maturity.

Habitat and ecology: — Found in humid, degraded and riverine forests and often in cultivation.

Vernancular name:— Mbera-Shizungou (dialect Comorien), Goyavier parfum (dialect Créole), M’bouera marashi.

Notes:— A widely cultivated plant in the tropics and subtropics becoming invasive in humid habitats, including natural evergreen forest and riparian vegetation.

Specimens examined:— MAYOTTE [ FRANCE]: Dzoumogne (fl.), Pobéguin 53 (P!) ; Combani , 13 June 2002 (fl.), A. Nègre 35 (P!) ; Ouangani, Coconi , 14 November 2001 (fl.), Barthelat 585 ( MAYOTTE!, P!). UNION OF THE COMOROS: Anjouan: Bungweni, Baraji, Bakotsumo, près Bungweni, 10 November 2009 (fl.), C. Loup 434 ( HKM!, P!). Grande Comore: Mvouni, Mkazi, route menant à Boboni, 14 November 1999 (fl.), s.n. (CNDRS, K!, MO, P!) ; Issinashjou Belvédère , 26 October 1975 (fl.), Coulon 193 (P!) ; environs de Nioumbadjou, 6 April 1975 (fl.), Coulon 38 (P!); Dachi , 7 October 1975 (fl.), Coulon 126 (P!) .

6. Syzygium labatii Byng & N. Snow sp. nov. Type : — MAYOTTE [ FRANCE]. Grande Terre , Chirongi , Choungi, Mont Choungi, 19 September 2002 (fl.), Barthelat 1021 (holotype P! [barcode P00290482]; isotypes G, K!, MAYOTTE!). Figure 9

A species resembling Syzygium comorense but differing in its usually shorter petioles, denser inflorescences and larger flowers.

Trees or shrubs, to 10 m; bark grey. Branchlets terete, drying grey to reddish-brown. Petioles 5‒8 × 1‒1.5 mm, slender. Leaves coriaceous; drying dark brown to bronze above, light brown below, dull to shiny above, dull below. Blades 4.5‒9 × 2.8‒5.5 cm, elliptic or oblong; base round to obtuse, apex acute or less often rounded or emarginate; margin flat to slightly revolute; secondary veins 14‒18, 2‒7 mm apart, more or less prominent on both sides, angle of divergence from mid vein 60–70°; tertiary veins many, fairly prominent and difficult to distinguish from secondary veins; inner intramarginal vein 1.5‒2 mm from leaf margin, outer intramarginal vein 0.2‒0.4 mm from leaf margin. Bracts and bracteoles ca. 1 mm long, oblong, caducous. Inflorescences terminal or rarely in subterminal leaf axils, dense, 1.5‒5 cm long, axes terete to subangular, flowers up to 50, in clusters of 8‒9. Flowers ca. 1‒2 cm in diameter at anthesis, buds ca. 4‒6 mm in diameter, pseudostalk 2‒4 mm long. Hypanthium 4‒5 × 6‒9 mm, infundibuliform, light green at the base and tinged pink to crimson above. Calyx lobes ca. 1‒1.5 × 4 mm, broadly rounded. Petals ca. 5 × 3 mm, calyptrate, orbicular. Stamens 8‒13 mm long, white; anthers ca. 1 mm long. Style 5‒8 cm long. Fruits ca. 1.5 × 1.5 cm, globose, dark red at maturity, disc 3‒4 mm diameter.

Distribution:— Endemic to Mayotte [ France].

Habitat and ecology:— Dense mixed natural forests at the summit of Mount Choungi; 400‒550 m elev.

Vernacular names:— Soaravo malandi, Soua ravou (dialect Shibushi), Soua mueou, Vory voa (dialect Shimaorais).

Affinities:— Closely related to Syzygium comorense but differing notably by its shorter petioles, denser inflorescences and larger flowers.

Etymology:— The species is named after the late Jean-Noel Labat (1959‒2011), of Muséum National d’Histoire Naturelle in Paris, who had a keen interest in the flora of the Comoros archipelago, as well as the genus Syzygium ( Labat and Schatz 2002) .

Paratypes:— MAYOTTE [ FRANCE]. Grande Terre , Chirongi , Choungi, Mont Choungi, 30 November 1997 (fr.), Labat 2922 (P!) ; Mont Choungi , versant sud, bord du GR au départ du village de Choungi, 25 July 2000 (fl.), Rouhan & Bernier 5 (P!) ; Mlima Choungi , 10 June 1996 (fl.), Pascal 561 (MO, P!) .

Conservation status:— The species is only known from the type locality, from a few individuals on the summit and surrounding areas of Mont Choungi. The area is in a nature reserve but encroachment from invasive species, tourism activities and agricultural expansion are occurring. The species has one subpopulation with an AOO three subpopulations with a total AOO of 1 km 2 and should be considered Critically Endangered (CR C2a(i,ii) D) according to the IUCN Red List Criteria ( IUCN 2014).

Figures

FIGURE 9. Syzygium labatii Byng & N. Snow. A Flowering branch showing lower leaf surface; B flowering branch showing upper leaf surface. C Close-up of the inflorescence. (A–C. Barthelat 1021). Scale bar = 2 cm.