Xanthostemon petiolatus (Valeton) Peter G. Wilson (1990: 459)

Mustaqim, Wendy A., Martiansyah, Irfan, Mambrasar, Yasper M. & Wilson, Peter G., 2022, Lectotypification of Xanthostemon petiolatus (Myrtaceae), Phytotaxa 559 (2), pp. 213-216 : 213-215

Xanthostemon petiolatus (Valeton) Peter G. Wilson (1990: 459) ( Figures 1 , 2 ).

= Nania petiolata Valeton (1900: 172 ; 1901: t. 99).

= Metrosideros petiolata (Valeton) Koorders (1912: 686) .

Type:— INDONESIA.? Java, Tjikemboelan, Scheffer K7 , 7 Oct 1871 (lectotype, designated here: BO 1829941 !) .

Shrubs or trees to ca. 8 m tall. Branchlets somewhat 4-angled; new growth pale reddish and grey-pubescent. Leaves opposite with petioles 8–20 mm long. Laminas elliptical to lanceolate, 25–60 (–75) × (12–) 50–125 (–170) mm, coriaceous, upper surface light green, lower surface paler; oil glands minute, dense; lateral veins crowded, spreading, 14–21 pairs, arcuate and ascending towards the margin but not forming an intramarginal vein; apex attenuate, acute or obtuse. Inflorescences crowded at apex of seasonal growth unit, mostly made up of metabotryoids and triads; axes densely grey-pubescent. Flowers mostly 4-merous, with pedicels 6–12 mm; sepals broadly triangular, 4.5–5.5 mm long, borne on a broadly cup-shaped hypanthium; petals cream, 5–6.25 mm in diameter; stamens numerous, in 2–3 series on a barely raised disk; filaments slender, filiform, 12–16 mm long, 2–3 times longer than the petals; anthers small, to 1.5 mm long. Ovary half superior, (3–)4-locular; style 12–15 mm long. Capsule subglobose, 15–20 mm in diameter, valves woody and rather erect; placentas persistent, rod-like and projecting from the axis obliquely into the upper part of the loculus.

Distribution:— Sulawesi, Maluku (Buru, Ambon, and Seram), and New Guinea (Papua Barat, Morobe, and Milne Bay). The locality of the type from Java is doubtful.

Habitat and ecology:—Lowland, coastal area, from sea level to 400 m, collected once at 1100 m elev.

Selected specimens examined (from a total of 48): — INDONESIA. Sulawesi Utara Province: Menado, Boalemo, Bilatto , 300 m asl, 21 Dec 1934, van Gobel 10 ( BO!) . Gorontalo Province: Molotaboe , 300 m, 27 Feb 1934, Stanp 122 ( BO!) . Sulawesi Tengah Province: Banggai, Lohoedangan, 80 m asl, Samel 3 ( BO!) ; Poso, Tanamawau, 400 m, 10 Apr 1940, Goma 4 ( BO!, L) . Sulawesi Tenggara Province: Kendari, Wawaroenggoe , 1 m, 6 Aug 1924, Walangitang 129 ( BO!) ; Buton Utara Game Reserve, Maligano-Ronta km. 15, 100 m, S 4º 41’ 57” E 122º 56’ 40”, 100 m, river sides, 29 Apr 2003, Uji 4748 ( BO!) . Sulawesi Selatan Province: Palopo, Malenjong , 1100 m, 23 Mar 1938, Thung Phang Soey 29 ( BO!) . Sulawesi (Province uncertain): Sulawesi, 1859-1860, de Vriese & Teijsmann 267 ( L!-image [ L.2522511]) . Maluku Selatan Province: Buru, Kajeli , Aug 1910, Teysmann s.n. ( BO!) ; Buru, 1859-1860, de Vriese & Teijsmann s.n. ( L!-image [ L.2522250]); Seram, W Ceram, Kairatu , Waiselang , 50 m asl, 22 Jun 1959, Kuswata & Soepadmo 202 ( BO!, L, K, P) . Papua Barat Province: Manokwari Selatan Regency, Momi Waren District, near port of Gaya Baru, near sea level, ca. 5–10 m, S 01° 38’ 31.5” E 134° 05’ 35.6”, W. A. Mustaqim 1631 ( BO!) ; W Nieuw Guinea, Soegarawa , 0 m asl, 14 Mar 1937, Salverda 608 ( BO!) . PAPUA NEW GUINEA. Morobe Province: Kamiali Wildlife Management Area, Bulili Ridge , S 07° 18’ E 147° 05’ 08.3”, 26 Jun 1999, Takeuchi & Senggo 15345 ( L!-image [ L.4148039]) . Milne Bay Province: Sewa Bay , Normanby Island, Esa’ala Sub-district , Milne Bay, S 10° 00 ” E 150° 55’, 3 m, 21 Oct 1971, Lelean & Streimann LAE 51514 ( L!-image [ L.2540487], LAE) .

Figures

FIGURE 1. Lectotype of Xanthostemon petiolatus in BO. Photograph by Irfan Martiansyah.

FIGURE 2. Xanthostemon petiolatus, Gaya Baru, Momi Waren District, Manokwari Selatan Regency, Papua Barat Province, Indonesia. A. Living plant. B. Fruiting branches. C–D. Inflorescence. E. Dehisced capsules. Scale bar: B = 2 cm, C–E = 5 mm. Photographs by W.A. Mustaqim.