Detennination ofFiber Saturation Point of Selected Sarawak and Exotic Wood Species

Wood is hygroscopic and therefore absorption and desorption occur naturally to achieve an equilibrium of moisture contents between wood and the surrounding environments. In wood, the sorption rate is different for different temperature and was dependent on wood species. Thus, fiber saturation point (FSP) is the key to determine the maximum amount of water that the composite layers of the cell walls can hold at a particular temperature and pressure. The FSP of 10 selected Sarawak wood species and 4 exotic species were determined by Awoyemi (adsorption-desorption intercept) method, Walker method, Awoyemi-Walker method and Vorreiter method. Results showed that the mean FSP of each species was significantly different (P<0.05) between the four methods. The FSP by Awoyemi method ranged from 19.83% to 61.25% between species, while the FSP for Walker's method, Awoyemi-walker's and Vorreiter method was range from 9.23% to 32.16%, 9.85% to 35.31% and 20.35% to 41.93% respectively. Analysis with wood physical properties, extractives contents and anatomical properties showed that not all the wood properties correlated significant with FSP. All 4 FSP methods were significantly positively correlated with water permeability (P<0.05). Also significantly negative correlation exists between basic density and water permeability, basic density and fiber lumen diameter, solvent extractives and fiber diameter, vessel density and vessel diameter; while positive correlation exists between solvent extractive and cold water solubility, cold water solubility and hot water solubility, fiber length and fiber diameter, fiber length and fiber wall thickness, fiber diameter and fiber lumen diameter (P<0.05)

Studies on Schismatoglottideae (Araceae) of Borneo LVI – Two new species of Schismatoglottis for the Nervosa Grade

Schismatoglottis amosyui S. Y. Wong, S. L. Low & P. C. Boyce, sp. nov. and S. pocong S. Y. Wong, S. L. Low & P. C. Boyce, sp. nov. are described and illustrated as taxonomically novel species belonging to the Nervosa Grade, a paraphyletic grade defined, uniquely for Schismatoglottideae, by aromatic vegetative tissues

Studies on Schismatoglottideae (Araceae) of Borneo XXIV — Two new species of Aridarum from Kalimantan, and notes on the Aridarum Burttii Complex

Two taxonomically novel Aridarum species, A. kazuyae and A. orientale, are described from Kalimantan Timur, Indonesian Borneo. They are most similar to A. burttii from Sarawak, and together with A. minimum from Kalimantan Barat represent a morphotaxon, here called the Burttii Complex, defined by staminate flowers comprised of one stamen with an obliquely excavated expanded connective, hemispherical interstice staminodes, a spathe limb deliquescing acroscopically from its junction with the lower persistent portion and leaf blades with adaxially prominently raised primary lateral veins. Recognition of the new species proposed here takes the genus Aridarum to 12 accepted species. A key to all Aridarum species is provided, the two new species are illustrated and a comparison plate of the spadices of the four species assigned to the Burttii Complex as well as notes on the defining morphological features of this species group and some brief observations on pollination are given

Schottarum (Schismatoglottideae: Araceae) substantiated based on combined nuclear and plastid DNA sequences

Recent studies on Schismatoglottideae have resulted in the recognition of four new monophyletic genera, the resurrection of two additional genera following clarification of their monophyly, and the publication of many taxonomically novel species. However, generic boundaries among some parts of Schismatoglottideae remain unclear owing to several reasons: (1) more taxa are being revealed through our on-going fieldwork, now expanded to previously unsampled localities on Borneo; (2) established occurrence of a high level of homoplasies among the morphological characteristics hitherto used to delimitate genera; and (3) gene regions used in previous studies contradicted some of current taxonomic placements. Among the unsolved groups from previous studies a clade comprising Schismatoglottis sarikeensis and S. josefii needs further investigation. Therefore, phylogenetic analyses were carried out to investigate the position of these two species using the nuclear region, internal transcribed spacer and combined plastid regions: trnL intron and trnLF intergenic spacer, coding matK?partial 30 trnK, intergenic spacer trnH-psbA. A total of 23 accessions representing 16 taxa of Schismatoglottideae and Philonotieae were included in the study. Phylogenetic analyses of a total 4,658 bp combined dataset using parsimony, maximum likelihood, and Bayesian methods revealed that S. sarikeensis and S. josefii do not belong to Schismatoglottis, and therefore are transferred to Schottarum (:Hottarum sarikeense : Schismatoglottis sarikeense). Flowering mechanism, pollination strategy, and fruitset of S. sarikeense are also presented in the paper

Studies on Schismatoglottideae (Araceae) of Borneo XXXV -Seven New species of Aridarum

ABSTRACT Seven new species of Aridarum are described and illustrated: Aridarum pende

Phylogeny and aspects of reproductive biology of aridarum (Schismatoglottideae: Araceae)

Aridarum Ridl., a genus of wholly rheophytes, is traditionally defined by its petiolar sheathextended intoafree ligularportion,notconstricted spathe, truncatestamenswithan excavated (not always) top and a pair of horn thecae, and infructescence with a cluster of berries subtended by obconic persistent lower spathe. Aridarum is further divided into two sections, sect. Aridarum and sect. Caulescentia based on primarily the position of the thecae horns. Recent discoveries of 16 novel species resulted in 400% increase in species number for the genus, making it to 25 published species. Therefore, this study was carried out to: (1) investigate the phylogenetic signals among Aridarum species; (2) examine the flowering behavior and its related floral microstructures of several selected Aridarum species; (3) determine the pollination strategies of A. nicolsonii Bogner, A. caulescens M.Hotta and A. velutandrum S.Y.Wong, S.L.Low & P.C.Boyce in its natural habitat; (4) link the floral traits of several selected Aridarum species to its pollination strategies

The diversification of thecae horns and their putative significance—a case study of Schismatoglottideae (Araceae)

Thecae horns are specialized anther extensions present in two tribes of Araceae: Cryptocoryneae and Schismatoglottideae. This structure is important in defning the generic boundaries and segregations within Schismatoglottideae. Eleven convergent lineages of thecae horns have evolved within Schismatoglottideae, contributing to the diverse stamen structures and thecae orientations. Here, we investigated the stamens of 22 taxa belonging to eight genera (Aridarum, Burttianthus, Hera, Heteroaridarum, Pursegloveia, Naiadia, Tawaia, and Toga) of Schismatoglottideae. We assessed the foral biology by focusing on the angle and movement of the thecae horns during the pistillate and staminate phases of anthesis. The angle of the thecae horns changed at the start of anthesis and, in several species, elevated further during staminate anthesis. Papillae cells, smooth or verrugated surface, are present on the thecae horns with the excavated connective often found to be smooth vs. non excavated connective, with verrugated surface. The presence of calcium oxalate packages decreases from pistillate phase to staminate phase of anthesis and is postulated to be a defense mechanism against predators

Studies on Schismatoglottideae (Araceae) of Borneo XXXXII: Additional new species of Aridarum

Three new species of Aridarum are described and illustrated: Aridarum perplexum S. Y. Wong, S. L. Low & P. C. Boyce from Kalimantan Barat, Indonesian Borneo, Aridarum sabahense S. Y. Wong, S. L. Low & P. C. Boyce from Sabah, Malaysian Borneo, and Aridarum spissum S. Y. Wong, S. L. Low & P. C. Boyce from Sarawak, Malaysian Borneo. Together these novelties take the genus Aridarum to 24 accepted, described species. The new species inserted into an updated identification key to Aridarum species

Studies on Schismatoglottideae (Araceae) of Borneo XXXV – Seven New species of Aridarum

Seven new species of Aridarum are described and illustrated: Aridarum pendek S.Y.Wong, S.L.Low & P.C.Boyce and A. velutandrum S.Y.Wong, S.L.Low & P.C. Boyce [Sarawak, Malaysian Borneo]; A. alatense S.Y.Wong, S.L.Low & P.C.Boyce, A. surukense S.Y.Wong, S.L.Low & P.C. Boyce, and A. zygosetum S.Y.Wong, S.L.Low & P.C.Boyce [Kalimantan Barat and Kalimantan Tengah, Indonesian Borneo]; and A. hebe S.Y.Wong, S.L.Low & P.C.Boyce [Kalimantan Utara, Indonesian Borneo]. Aridarum caulescens var. angustifolium Bogner & Nicolson is shown to represent a further undescribed species from Sarawak, and is here published as Aridarum orestum S.Y.Wong, S.L.Low & P.C.Boyce. Together these seven novelties take the genus Aridarum to 21 accepted, described species. An identification key to all species is provided