Tree Flora of Sabah and Sarawak

 Acer laurinum Hassk.  (Latin, laurinum = resembling Laurus; the blue-grey colour of the leaves) Medium-sized to large tree up to 50 m tall; clear bole straight, cylindrical, up to 28 m tall and 70 cm diameter; buttresses about 1.5 m high and 2 m out, thin, spreading, slightly concave; crown dense, pale fresh green from below, more or less conical to hemispherical, deciduous to semi-evergreen.  Bark initially smooth, greenish grey, becoming rich red to grey-brown and longitudinally fissured and flaky with age; inner bark c. 1.5 cm thick, firmly fibrous, yellow-brown to red-brown, somewhat mottled, sometimes laminated. Heartwood absent; sapwood white to pale yellow, with rather distinct concentric growth rings. Twigs slender, terete or ribbed, drying nearly black, with numerous leaf-scars and minute lenticels. Buds numerous, c. 4 mm long, covered by 4–11 pairs of decussate, caducous scales of c. 2 mm long.  Leaves thinly leathery, glabrous, elliptic to ovate-lanceolate, 7–23 x 3–6 cm,

1. Acer L.  Deciduous trees or shrubs with smooth bark. Leaves pinnately veined, more or less distinctly 3-veined at the base, long-stalked. Flowers unisexual, male and female on the same or different trees, organised in terminal or axillary racemes, corymbs, or panicles; sepals and petals imbricate in buds. Other floral, fruit and seed characters as in the family. Distribution . As for the family. Ecology . The samaras are wind-dispersed. Uses. Many temperate species yield valuable timbers and a few others produce sugar/maple syrup obtained by boring holes through the bark in February and March each year. A number of shrubby species make excellent ornamental plants because of their strikingly coloured (yellow, red and purple) aging foliage. The timber of the Malesian species is only occasionally used for light construction. Taxonomy . In a number of earlier publications (e.g., Blume, Rumphia 3 (1847) 193; Miquel, Fl. Ind. Bat. 1, 2 (1859) 581; Bentham & Hooker f., Gen. Pl. 1 (18

Flora of Sabah and Sarawak 1. Aceraceae Authors: A. Noorsiha Trees or shrubs. Buds with protective scales. Leaves opposite-decussate, simple, palmately or pinnately veined, without stipules. Flowers in fascicles, panicles, racemes or corymbs, regular, often unisexual; sepals and petals 4–5, rarely without petals; disc annular or lobed, or reduced to teeth, rarely absent, intra- or extra-staminal; stamens (or staminodes) (4–)8(–10), hypogynous or perigynous, filaments free; ovary often present in rudimentary form in male flower, in female flowers 2-locular, superior, compressed, styles 2, free or connate at base, ovules 2 in each locule, placentation axile. Fruit composed of 2 one-seeded, onewinged samaras. Seeds without endosperm; embryo with folded cotyledons. Distribution.  Two genera (Acer and Dipteronia) with about 200–250 species distributed mainly in mixed deciduous forests of the northern temperate zone. Only  one genus  (Acer) with one species in  western Malesia. Taxonomy . Cl

Flora of Sabah and Sarawak Family Name          # Lower Taxa Aceraceae                1

 Introduction BACKGROUND TO THE TREE FLORA OF SABAH AND SARAWAK PROJECT E. Soepadmo Forest Reseach Institute Malaysia, Kepong, Malaysia Why a Tree Flora of Sabah and Sarawak? B orneo, the third largest island in the world, of which Sabah and Sarawak are parts, has been frequently acknowledged as one of the most important centres of plant diversity in the world. The island, which occupies a total land area of approximately 740,000 sq. km, is conservatively estimated to harbour 10,000–12,000 species of flowering plants, representing about 5–6% of the world total (Merrill 1950; van Steenis 1950; Kiew 1984; Mat-Salleh et al. 1992). Of these, 40–50% are endemic to the island , and up to 80% of the endemic species in Borneo occur in Sabah and Sarawak. In certain localities in Sabah and Sarawak, where botanical exploration has been carried out more intensively, the species diversity is indeed extremely high. Beaman & Beaman (1990), for instance, have found that the flora of the Mt Kinaba

 Flora of Sabah and Sarawak, Malaysia Flora of Sabah and Sarawak Online Volumes Introduction Volume 1    Chapter 1 Aceraceae