West Malesia Research Articles

The Malesian species of Dalechampia (Euphorbiaceae)

Dalechampia is a mainly South American genus of generally climbing shrubs with usually sharp stiff trichomes in some of the inflorescence parts. The bisexual inflorescences are very condensed and subtended by two, often showy, large bracts. The three pistillate flowers are separate from the staminate subinflorescence (both groups with their own bracts). The staminate subinflorescence contains groups of staminodial-like bractlets that provide resin for female bees or fragrance for male bees. In west Malesia (Sumatra and Java) one indigenous species is found, the climbing D. bidentata, and occasionally cultivars of the subshrub D. spathulata.

The diversity and distribution of Alpinia zerumbet clade in West Malesia

Abstract. Setiawan E, Ardiyani M, Miftahudin, Poulsen AD, Chikmawati T. 2022. The diversity and distribution of Alpinia Zerumbet clade in West Malesia. Biodiversitas 23: 1734-1744. Alpinia belongs to the family Zingiberaceae and tribe Alpinioideae. One of the centres of Alpinia diversity is in Malesia, yet information regarding the taxon in this area is very limited. Furthermore, species richness and distribution in West Malesia have not been well documented particularly in respect of the taxonomical development following clade classification. The aim of the current paper is to study the morphological diversity and distribution of Alpinia Zerumbet clade in West Malesia to provide taxonomic information. Exploration was done in several locations in Java and Sumatra. Data were obtained from fresh and herbarium specimens preserved in three herbaria (BO, SING, BRUN), as well as digitally (L, E, and K). A total of 16 Alpinia species are placed in the clade of Zerumbet classified into a section, namely section Alpinia were recorded in West Malesia. They share several characters: i.e. absent or caducous secondary bracts, small or reduced lateral staminodes, and often having a petaloid and showy labellum. The highest diversity of Alpinia Zerumbet clade is recorded in the Philippines and Borneo (each has 7 species) and the lowest diversity is in Java (2 species). The most abundant habitat is in the lowlands and mountain rainforests. Most species of Alpinia Zerumbet clade are found in primary forest and secondary forest (Pinus or Agathis forest). A determination key was constructed based on information in the literature and direct observations of herbarium specimens.

The occurence of Croton bonplandianus in Java and a new record of Caperonia palustris for Malesia Region

Two noteworthy species belongs to the Euphorbiaceae, namely Caperonia palustris and Croton bonplandianus, have been recently collected from Java Island, West Malesia. The discovery of C. palustris is a new record for Malesia region, while C. bonplandianus is considered as a newly recorded alien species to the Flora of Java. Caperonia palustris is characterized by the glandular and non-glandular hairs on its stem and petiole, triangular to lanceolate or subulate stipules, and leaves in ovate-oblong or elliptic-oblong to lanceolate shape. Croton bonplandianus differs from the previously reported species in Java, C. hirtus, by its non-irritating hairs on the stem, sessile basal leaf glands, leaf margin with simple serration, and ellipsoid fruit. Descriptions and a brief discussion are given.

<p><strong>Second-step lectotypification of <em>Fimbristylis alboviridis</em> (Cyperaceae)</strong></p>

Fimbristylis alboviridis C.B. Clarke (1893: 638) was described based on the collections of Griffith, Hooker and Jenkins from East Bengal, River Megna and Upper Assam, respectively. The species is mainly distributed in West & West Central tropical Africa, tropical Asia, Indo-China and Malesia (Govaerts et al. 2020). In India, it is confined to Andhra Pradesh, Assam, Bihar, Goa, Karnataka, Madhya Pradesh, Maharashtra, Meghalaya and Uttar Pradesh (Patil & Prasad 2009, Anitha 2011, Prasad 2017, Kumar et al. 2017). The species is often confused with F. dichotoma (Linnaeus 1753: 50) Vahl (1805: 287). Fimbristylis alboviridis is characterized by nutlets bearing 10 to 16 vertical rows on either side while the latter has 5 to 10 rows (Prasad 2017).

<p><strong>Typification of the names <em>Michelia cathcartii</em> and <em>Magnolia gustavii</em> (Magnoliaceae)</strong></p>

The genus Magnolia Linnaeus (1753: 398) is represented by ca. 219 species, distributed in Himalaya to Japan & West Malesia and north-eastern America to tropical America (Mabberley 2017). In India, it is represented by 25 species (Raju 1993, Kundu 2009, POWO 2019), out of which two species [M. punduana (Hooker & Thomson 1855: 81) Figlar (2000: 23) and M. pleiocarpa (Dandy 1933: 313) Figlar & Nooteboom (2004: 95)] are endemic to India (Singh et al. 2015).

A new record of Euphorbia atoto (Euphorbiaceae) in Bangka Belitung and notes of Coptosapelta hammii (Rubiaceae) for Borneo

Euphorbia atoto (Euphorbiaceae) and Coptosapelta hammii (Rubiaceae) have been recently collected from Belitung Islands, east of Sumatra, west Malesia. The discovery of Euphorbia atoto, combined with specimens kept in BO, is a new record for Bangka and Belitung Island, while C. hammii is considered to be an important rediscovery of a species thought to be endemic. Further examination of previously collected materials of C. hammii shows that this species has also been collected from Borneo, which means this species is no longer endemic to Belitung. Descriptions, photographs, notes on uses and a brief discussion are given.

FLORA OF SINGAPORE PRECURSORS, 2. A NEW SPECIES AND TWO NEW COMBINATIONS IN PSYDRAX (RUBIACEAE: VANGUERIEAE) FOR WEST MALESIA

WONG, K. M. & MAHYUNI, R. 2018. Flora of Singapore Precursors, 2. A new species and two new combinations in Psydrax (Rubiaceae: Vanguerieae) for West Malesia. Reinwardtia 17(1): 77–84. — Studies in Psydrax Gaertn. for the Flora of Singapore and the Malesian floristic region have revealed that three taxa required the description of a new species and two new combinations. Psydrax undulatifolius K.M.Wong & Mahyuni is newly described as a species thus far recorded only for the Malay Peninsula, whereas Psydrax approximatus (Korth.) Mahyuni & K.M.Wong and Psydrax lucidulus (Miq.) Mahyuni & K.M.Wong are newly combined from Canthium approximatum Korth. and Vangueria lucidula Miq., both distributed in Sumatra, the Malay Peninsula and Borneo.

A PHENETIC STUDY OF THE CALAMUS FLABELLATUS COMPLEX (PALMAE) IN WEST MALESIA

SYAM, N., CHIKMAWATI, T. & RUSTIAMI, H. 2016. A phenetic study of the Calamus flabellatus complex (Palmae) in West Malesia. Reinwardtia 15(1): 27 - 41. — The number of species within the Calamus flabellatus complex is still under controversy because the taxonomic status of the species is not yet clear. Morphological observations were conducted on 119 collections of Calamus in the Herbarium Bogoriense (BO) and specimen images from the Singapore Herbarium (SING) and Kew Herbarium (K). The results showed that C. flabellatus complex (all species related to C. flabellatus) in West Malesia consisted of eight species and two varieties, i.e. C. acuminatus, C. amplijugus, C. congestiflorus, C. corrugatus, C. flabellatus, C. hypertrichosus, C. javensis, and C. ruvidus. They can be distinguished using several characters, i.e. leaf sheath, knee, ocrea, leaves, inflorescence, shape of fruit, number scale of fruit and seed. Calamus flabellatus var. laevibus and C. flabellatus var. congestispinosus are two new proposed varieties. Phenetic analysis of C. flabellatus complex in West Malesia divided all species into two major clusters with similarity coefficient of 46%.

A revision of the Malesian species of <I>Blachia</I> (<I>Euphorbiaceae</I>)

Malesia harbours one, possibly two species of Blachia. In the Philippines B. philippinensis is found and this species is not synonymous with B. andamanica. In literature B. andamanica has been recorded for west Malesia, but no specimens were seen. Based on its presence in Peninsular Thailand and the Andamans it is likely to be present in Peninsular Malaysia. The most distinct difference between both species is in the indumentum of the ovary, sparsely hairy in the lower half versus densely and completely sericeous, respectively.

Elaeocarpus for Flora Malesiana: the Monocera group in western Malesia

Summary. An overview of taxa currently gathered under the ‘Monocera Group’ in West Malesia (here treated as comprising Peninsular Malaysia, Sumatra and Java) is offered. The widespread Elaeocarpus macrocerus (Turcz.) Merr. is distinguished from the superficially rather similar E. obtusus Blume, of rather similar distribution. E. achmadii Coode, from Simuelue Is., Sumatra, most similar to E. macrocerus, is described as a new species. One new subspecies of E. obtusus (subsp. krukovii Coode from Peninsular Malaysia and Sumatra) is described. E. ngii Coode from Peninsular Malaysia (previously determined in herbaria as a subspecies of E. obtusus) is described as new, with a new subspecies curtisii Coode from Penang Island. E. pierrei Koord. & Valeton, from Java and Sumatra, seems intermediate between E. macrocerus and E. obtusus and some elucidation is offered. A key to the c. 11 taxa in this group in West Malesia is proposed. E. heinrichii R. Knuth (from SE Sulwesi), although not found in West Malesia, is reduced from specific rank to subspecies under E. macrocerus.

A revision of Ptychopyxis (Euphorbiaceae) in southeast Asia

Ptychopyxis is a genus comprised of 11 species. Nine are found in southeast Asia mainland and west Malesia and two species are endemic to New Guinea. One of the endemic New Guinean species is newly described here, viz. P. esdras Stoops sp. nov.

<I>Flueggea</I> (Euphorbiaceae s. l. or Phyllanthaceae) in Malesia

Abstract Flueggea (including Richeriella) is revised for the Flora Malesiana area. Three species are recognized. Two of them are generally small trees and they are allopatric, F. gracilis (ex-Richeriella) being present in West Malesia and F. flexuosa in East Malesia and the west Pacific. The two subspecies of the generally shrub-like F. virosa are also allopatric, with subsp. virosa having a palaeotropical distribution ending just west of New Guinea, and subsp. melanthesoides being present in New Guinea and Australia.

Revision of the Asian Genus Koilodepas (Euphorbiaceae)1

Koilodepas Hassk. (Euphorbiaceae) is a genus of nine accepted species ranging from India (K. calycinum Bedd.) to Southwest China, Indochina, Southeast Asia, West Malesia, and New Guinea (K. homaliifolium Airy Shaw). Two species are widespread on the southeastern Asian mainland and in western Malesia (K. bantamense Hassk. and K. longifolium Hook. f.), one species is present from China to Thailand (K. hainanense (Merr.) Croizat), three others (K. brevipes Merr., K. laevigatum Airy Shaw, K. pectinatum Airy Shaw) are endemic to Borneo, and a new species is found on Sumatra only (K. cordisepalum Welzen & Muzzaz.). The name K. glanduligerum Pax & K. Hoffm. is lectotypified. Typical for the species is the presence of stellately bundled hairs; spicate inflorescences with a single pistillate flower per node basally and more apically tight, globose groups of small staminate flowers per node; and staminate flowers with a broad, short androphore with the typically shaped, sulcate filaments and divergent anthers (K. laevigatum excepted). The species are difficult to distinguish morphologically. Typical characters of the species are found in the leaf margin (serrulate vs. entire), the base of the leaf blade (convex vs. flat), the color of the dried leaves (green or brown), the type of stamens (threadlike filaments vs. sulcate ones), and especially in the calyx and stigmas of the pistillate flowers (sepals free vs. completely united, loose vs. tight around ovary, enlarging in fruit vs. not enlarging in fruit, and degree in which stigmas branch apically).

The Genus Alchornea (Euphorbiaceae) in the Malay Archipelago and Thailand

The genus Alchornea in the Malay Archipelago (= Malesia) and Thailand comprises only five instead of eleven species as recognized by current literature. They can be divided into two groups. One group, section Cladodes, with only one variable, widespread species (India to Australia) has obovate leaves and lacks stipellae (A. rugosa, including A. pubescens and A. petalostyla). The other group, section Stipellaria, has ovate leaves and stipellae. In this group, A. tiliifolius (including A. villosa) and A. parviflora (including A. borneensis, possibly A. adenophylla, and what was known as A. trewioides in Thailand) are widespread species (India to West Malesia); Alchornea sicca (including the Indochinese A. coudercii) is found in the Philippines and Indochina, and A. rhodophylla is only present on Penang Island in Peninsular Malaysia. The main distinguishing characters can be found in the indumentum, shape of the leaves, stipellae, roughness of the ovaries and fruits, size of the bracts and pistillate sepals. Alchornea trewioides, formerly recorded for Thailand, extends only to S.E. China and N. Vietnam; it can be distinguished from the closely similar A. liukiuensis from Taiwan and the Ryukyu Islands.

Molecular phylogeny of Pinanga (Palmae) based on internal transcribed spacers (ITS) sequence data

Molecular phylogeny of 52 species of Pinanga (Palmae) were investigated using the internal transcribed spacer (ITS) sequence data of nuclear ribosomal DNA. Polymorphic sequence data were identified in the ITS region of Pinanga, indicating that concerted evolution is not completely homogenizing ITS repeats in the nuclear genome. The strict consensus of Pinanga used in the study showed that the genus is monophyletic. Pinanga rivularis and P. aristata formed the basal clade; followed by P. albescens, P. brevipes, P. veitchii, P. sessilifolia and P. crassipes as sister taxa; and P. disticha, P. watanaiana, and P. pulchella were sister taxa to the clade containing the sampled species of Pinanga used in the study. In general, two major clades were recognized: first, Pinanga from Wallacea, East Malesia and adjacent region clade and second, Pinanga from West Malesia and adjacent region clade. The clade separation was strongly correspond with geographical distribution and it did not support infrageneric classification based on distichous and sprirally triads flower described by Beccari (1886). Conforming phylogenetic tree generated by ITS sequence data and morphological observations appear that habit, size and form of stem, leaf and inflorescence were not useful characters for infrageneric classification of Pinanga. Examination of phylogenetic relationships using combination of morphological characters including pollen morphology, cytological data, nuclear genome size and DNA sequence data are necessary for providing a more accurate picture of phylogenetic relationships and affords the opportunity to garner insights into evolutionary process of Pinanga.

Altitudinal zonation of vegetation in the Padang region, West Sumatra, Indonesia

The altitudinal gradient of vegetation of the Barisan range in a coastal region near Padang, West Sumatra, was studied in 10 plots (0.1-6.55 ha) distributed from 600 to 1780 m. Trees with a diameter at breast height of more than 10 cm were employed for classification of the vegetation. Four vegetation zones, two types of montane and two types of lowland vegetation, were recognized based on cluster analysis, floristic information, and the physiognomy of these forest stands. An upper zone of montane vegetation (Lower montane Fago-Myrtaceous forest) was distinguishable from a lower zone (Sub-montane Fago-Myrtaceous forest) due to the remarkable dominance of several species of Fagaceae and Myrtaceae, and its lower canopy height. The two zones of lowland vegetation (Upper hill dipterocarp forest and Mid-hill dipterocarp forest) were distinguishable by their species composition of Dipterocarpaceae and stratification of the stand. The altitudinal zonation corresponded well with classic zonation patterns previously reported for West Malesia, but the critical threshold altitudes were lower in comparison with those in other regions. The borderline between the lowland and montane vegetation, corresponding to a Kira’s warmth index of WI = 180 °C · month, was around 200 m lower in Padang than in other regions of West Malesia, and the critical altitude between the two zones of lowland vegetation was also around 300 m lower in Padang than on Mt. Kinabalu. The characteristics of altitudinal zonation in Padang were discussed with reference to the climatic features of this region, namely, the low temperature and hyperhumidity.

Revision of Annesijoa, Elateriospermum and the Introduced Species of Hevea in Malesia (Euphorbiaceae)

Annesijoa is an endemic monotypic genus from New Guinea with as single species A. novoguineensis. Elateriospermum is also monotypic (E. tapos) and found in West Malesia. The South American genus Hevea comprises about 10 species. One species (H. brasiliensis) is presently cultivated worldwide in plantations for its rubber and has become one of the major economic products of SE Asia. Two other species, H. guianensis and H. pauciflora are sometimes present in Malesian botanical gardens.

<p><strong>Additions To The Moss Flora of Endau Rompin National Park, Johore State, Peninsular Malaysia</strong></p>

In a recent survey of the Endau Rompin National Park (ERNP) in Johore State, 81 species and 4 varieties of mosses were documented. This increases the previous count from 62 species and 3 varieties of mosses in ERNP to 111 species and 5 varieties in total. Of these, 30 species are new records for Johore State. Rhaphidostichum bunodicarpum and Trichosteleum stigmosum are two species new to Peninsular Malaysia. Thuidium assimile is a new record for West Malesia. A new combination, Papillidiopsis aquaticum (Dix.) Boon-Chuan Ho & B.C. Tan is proposed. In terms of species composition, the pan-tropical families of Calymperaceae, Fissidentaceae, Leucobryaceae and Sematophyllaceae predominate the moss flora of ERNP.

Calamus longipinna (Arecaceae: Calamoideae) and Its Relatives in New Guinea

Summary. The taxonomy and morphology of the Calamus longipinna (Arecaceae) group is revised and discussed. This group of rattan species from New Guinea and the Solomon Islands is defined by the possession of a distinctive, inflated ocrea at the mouth of the leaf sheath and rather uniform A striking feature of the New Guinea species of the rattan genus Calamus is the frequent presence of elaborate ocreas. The ocrea is widespread in some other rattan genera, namely Korthalsia, Plectocomiopsis, Laccosperma, Eremospatha and Oncocalamus. In most cases, the structure is merely a low, inconspicuous, tubular extension of the leaf sheath above the insertion of the petiole. However, in some species of Calamus, Korthalsia and Laccosperma, the ocrea is enlarged, highly conspicuous and widely variable in morphology. For example, some ocreas are inflated and clasp the stem or diverge from it at an acute angle. Ants often colonise inflated ocreas, cultivating scale insects for honeydew on the leaf sheaths and aggressively defending their home, and, at the same time, the rattan (Dransfield 1979). In a few species of Korthalsia and one species of Calamus, the ocrea consists of a reticulum of fibres which is tightly adpressed to the sheath or else expands into an open funnel. A number of Calamus species (e.g. C. paspalanthus Becc. in west Malesia and C. zebrinus Becc. in New Guinea) possess greatly enlarged ocreas, sometimes as long as 1 m or more, that disintegrate and fall not long after emergence. Approximately 14 species of Calamus in New Guinea possess such enlarged ocreas. The C. longipinna Lauterb. & K. Schum. group, the subject of this paper, is characterised by its inflated ocreas that clasp the stem and a characteristic yet rather simple flagelliform inflorescence morphology. The group is distinguished from the ocreate species related to C. macrochlamys Becc. and C. zebrinus Becc. because it does not possess the unusual floral cluster architecture that is so remarkable in this group (Dransfield & Baker, submitted). Calamus humboldtianus Becc. is not included in the C. longipinna group because it bears bizarre inflorescences with congested branches as well as unusual leaf and ocrea morphology. The fibrous, fragile ocrea and robust rachillae of C. klossii Ridl. set it apart from other New Guinea ocreate rattans. Calamus distentus Burret may yet prove to be a relative of the C. longipinna group, but the ocrea diverging from the stem and very slender inflorescence morphology are not congruent with such a placement.

Two New Species of Daemonorops (Arecaceae) from Vietnam

Summary. Daemonorops mollispina J. Dransf. and D. poilanei J. Dransf., previously misidentified in Indochinese floras as D. longispatha var. mollispina and D. geniculata, are described as new. The rattan genus Daemonorops is divisible into two sections, based on the form of the inflorescence bracts. Section Daemonorops ("Cymbospatha" of Beccari 1902) has inflorescences in which the prophyll encloses all the other bracts on the inflorescence axis, the tips of subsequent bracts remaining enrolled within the tip of the prophyll. At anthesis these bracts split along their length, but, captured by the prophyll, persist until they begin to decay long after anthesis. In section Piptospatha, the prophyll is generally shorter than subsequent bracts and its tip does not enclose the tips of the other bracts. At anthesis the inflorescence rachis tends to elongate, the bracts splitting longitudinally, and usually falling, leaving the prophyll split but still attached, and each subsequent bract leaving a circular scar on the inflorescence axis. Section Piptospatha has a more restricted distribution than does section Daemonorops. While the latter section is distributed from the Himalayas and Andaman Islands, and southern China through to the Aru Islands, Piptospatha is most abundant in west Malesia with a few species in Peninsular Thailand and a few in Sulawesi and the Moluccas, and one reaching as far as Irian Jaya. In Indochina, one species belonging to section Daemonorops, D. jenkinsiana (Griff.) Mart., is very widespread. Several different species such as D. pierreana Becc. and D. margaritae (Hance) Becc. have been recognised, but recent studies by Tom Evans and coworkers in Laos have shown the variation to be continuous. The first record of members of section Piptospatha in Indochina was published by Conrard (in Gagnepain & Conrard 1937) in Flore Gindrale de l'Indochine. He provided descriptions of two species from Vietnam, Daemonorops longispatha Becc. var. mollispina Conrard and D. geniculata (Griff.) Mart. The former species (as var. longispatha) is a very distinctive robust species described by Beccari, endemic to Borneo where it is restricted to maritime habitats, being particularly abundant on the landward fringe of mangrove and on poor rocky soils along the coasts (Dransfield 1992). Although the variety mollispina seems to be attributed to Beccari by Conrard, I can find no mention of this name in Beccari's writings, neither is the presence of a member of section Piptospatha mentioned by Beccari in his account