Xanthostemon petiolatus Peter G. Wilson 1990
Creators: name: Mustaqim, Wendy A.
name: Martiansyah, Irfan
name: Mambrasar, Yasper M.
name: Wilson, Peter G.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae
Xanthostemon
Xanthostemon petiolatus

description: 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).
description: Published as part of Mustaqim, Wendy A., Martiansyah, Irfan, Mambrasar, Yasper M. & Wilson, Peter G., 2022, Lectotypification of Xanthostemon petiolatus (Myrtaceae), pp. 213-216 in Phytotaxa 559 (2) on pages 213-215, DOI: 10.11646/phytotaxa.559.2.11, http://zenodo.org/record/7021461