The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. Howev... more The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. However, during a visit in April 2013 three populations are located close together with more than twenty buds and some rotting blooming flowers, Tetrastigma sp. was detected. Field observations could be made and material was collected for comparison with that in the Herbarium Bogoriense (BO). It was concluded that they are R. gadutensis Meijer, which is known from Padang, Ulu Gadut. Notes on its morphology are given. The distribution of species is discussed.
Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan... more Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan Selatan National Park, Province of Lampung. The study sites was focused on secondary lowland forests of Way Canguk and Sukaraja Atas. The research was aimed to obtain floristic data from such areas that has never been recorded. Flora diversity in these areas is relatively high as represented by 183 plant species from 124 genera and 60 families. It is noted that 3 species are newly for Sumatran flora.
Sumatra is described. The species was previously recorded as either R. arnoldi or R. atjehensis, ... more Sumatra is described. The species was previously recorded as either R. arnoldi or R. atjehensis, but it is distinguished by the absence of windows, the large undulating exterior annulus, the short pubescence on the upper surface of perigone lobes, and the very wide of diaphragm opening. A key to species of Sumatran Raffesia is provided.
Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos... more Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kompleks ( Rubiaceae ) di Malesia, dengan tiga jenis baru. Floribunda 5(8): 323–331. —. Psydrax dicoccos Gaertn., merupakan jenis tipe dari Psydrax Gaertn., hanya mempunyai dua sampel buah sebagai bahan tipenya. Terbatasnya material tipe menghasilkan kesalahan yang menyebabkan jenis yang berbeda diberikan nama P. dicoccos. Sebanyak 140 lembar spesimen herbarium yang diidentifikasi sebagai P. dicoccos di kawasan Malesia, ditentukan sebagai takson yang berbeda dan ditunjukkan dengan tiga jenis baru yaitu Psydrax elmerianus, P. koordersianus dan P. sumatranus. Diagnostik karakter masing-masing jenis disediakan. Kata Kunci: Malesia, jenis baru, Psydrax . Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. The Psydrax dicoccos Complex ( Rubiaceae ) in Malesia, with Three New Species. Floribunda 5(8): 323–331. — . Psydrax dicoccos Gaertn., the type species of Psydrax Gaertn., is typified by a specimen consisting of two detached fruits. The limited type material has resulted in a number of distinct species being wrongly referred to that species. Approximately 140 herbarium specimens identified as P. dicoccos in the Malesian region are shown to represent three new species, Psydrax elmerianus, P. koordersianus and P. sumatranus. The diagnostic characteristics of these species are provided. Keywords: Malesia, new species, Psydrax .
Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan... more Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan Selatan National Park, Province of Lampung.The study sites was focused on secondary lowland forests of Way Canguk and Sukaraja Atas. The research was aimed to obtain floristic data from such areas that has never been recorded. Flora diversity in these areas is relatively high as represented by 183 plant species from 124 genera and 60 families. It is noted that 3 species are newly for Sumatran flora.
Canthium longipetalum Y.H.Tan & S.S.Zhou in Yang et al. (2019: 197) is a species of Rubiaceae rec... more Canthium longipetalum Y.H.Tan & S.S.Zhou in Yang et al. (2019: 197) is a species of Rubiaceae recently described from northern Myanmar. This species was identified as belonging to the Vanguerieae tribe, and was placed provisionally in the genus Canthium Lamarck (1783: 602) based on morphological characters including the presence of axillary inflorescences, valvate corolla aestivation, two-locular ovaries, and a two-lobed stigma (Yang et al. 2019). However, the suite of characters cited by the authors to support the placement of their species in Canthium define an overly broad and now-superseded concept of the genus.
Ramentae are hair-like structures found on the perigone tube and diaphragm in species of Rafflesi... more Ramentae are hair-like structures found on the perigone tube and diaphragm in species of Rafflesia (Rafflesiaceae). Although ramenta morphology provides an important taxonomic character, a consistent terminology has not been used in species descriptions. As such, morphological comparisons among species as well as among populations within a species are difficult. We used a variety of resources to document the morphology including the location and density of ramenta among 18 species of Rafflesia and between populations and/or sexes of two species. We identified five types of ramenta: tuberculate, filiform, swollen apex, toadstool, and fence-like and recognized several variations within each type. Ramenta types characterize four species complexes: R. patma (tuberculate), R. arnoldii (filiform), R. pricei (mostly swollen apex), and R. hasseltii (mostly toadstool). Our classification of ramenta offers a tool for using consistent terminology to re-evaluate previously described species and to define new species of Rafflesia.
Rafflesia zollingeriana Koord. was one of Rafflesia that distributed in Java. Although it has bee... more Rafflesia zollingeriana Koord. was one of Rafflesia that distributed in Java. Although it has been stated as a different species, R. zollingeriana is sometimes still regarded as a synonym of R. patma. In addition, there are several contradictions in description of R. zollingeriana. Therefore, further investigation is needed. This study attempts presents a full the description of the R. zollingeriana female flower. In this study, a full description of female flower of R. zollingeriana and pictures of important characters such as ramenta, annulus, perigone lobes, disc, processes, bractea are presented. This study is also compared the morphology of R. zollingeriana and R. patma, to confirm their differences in size, opening of diaphragm, blotches and warts pattern on perigone lobes and diaphragm, annulus, and ramenta.
The plant in the collection of C. Hose 751 is somewhat stouter as hitherto known, with the leaf b... more The plant in the collection of C. Hose 751 is somewhat stouter as hitherto known, with the leaf blade ca. 20 by 17.5 cm and the male peduncle ca. 15 cm long. Female flowers of this species are still not known. (2) RE-DESCRIPTION OF TRICHOSANTHES CELEBICA Cogn. When conceiving T. celebica Cogn. (1881: 385) for the revision of Trichosanthes (Rugayah, 1999; de Wilde & Duyfjes, 2010), it was assumed that the following four collections from E. Sulawesi: Beccari 51 (type, consisting of a male specimen and one fruit), Kjellberg 1212 (male, BO, S, not seen by de Wilde at the time, though recently we could examine and identify the S-duplicate as T. tricuspidata Lour.), de Vogel 6136 (fruit), and de Wilde & Duyfjes 21903 (sterile), and one from Buru: Nooteboom 5275 (sterile) all belonged to that species. With recent molecular sequencing of the collection of de Vogel 6136, as part of a larger molecular analysis of the whole genus Trichosanthes
MAHYUNI, R., KUSUMA,Y. W. C., WIHERMANTO & VELDKAMP, J. F. 2015. Notes on Rafflesia (Rafflesiacea... more MAHYUNI, R., KUSUMA,Y. W. C., WIHERMANTO & VELDKAMP, J. F. 2015. Notes on Rafflesia (Rafflesiaceae) in Sumatra with a new record Rafflesia gadutensis Meijer. Reinwardtia 14(2): 317 - 322. Pulau Mursala is a small island west of the Sibolga, Tapanuli Tengah District, North Sumatra, Indonesia. The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. However, during a visit in April 2013 three populations are located close together with more than twenty buds and some rotting blooming flowers, Tetrastigma sp. was detected. Field observations could be made and material was collected for comparison with that in the Herbarium Bogoriense (BO). It was concluded that they are R.gadutensis Meijer, which is known from Padang, Ulu Gadut. Notes on its morphology are given. The distribution of species is discussed.
MAHYUNI, R., CHIKMAWATI, T., ARIYANTI, N. S. & KUSUMAWATY, A. 2022. A new variety of Canthiumera ... more MAHYUNI, R., CHIKMAWATI, T., ARIYANTI, N. S. & KUSUMAWATY, A. 2022. A new variety of Canthiumera glabra (Rubiaceae: Vanguerieae). Reinwardtia 21(1): 13‒17. — Canthiumera glabra var. laxiflora (Rubiaceae: Vanguerieae), a new variety from Java and Sumatra is described. The new variety differs from the typical variety in having laxly branched inflorescences and is restricted to south Sumatra (Lampung) and southwestern Java.
typically valvate or contorted, sometimes imbricate in bud; stamens usually as many as and altern... more typically valvate or contorted, sometimes imbricate in bud; stamens usually as many as and alternating with corolla lobes, in heterostylous flowers typically occurring at different levels in the corolla throat of the different morphs; filaments inconspicuous or long; anthers dorsi-or basifixed, introrse, thecae 2, dehiscing lengthwise, rarely with apical pores; ovary basically inferior, rarely becoming (half-)superior during fruit development, syncarpous, locules (1−)2 or sometimes more, nectar-secreting disk often present at ovary apex; placentas axile, parietal, basal or apical; ovules 1−many in each locule, mostly anatropous; style mostly simple, rarely divided into branches; stigmas capitate, clavate or 2-to several-lobed. Fruits small or large, indehiscent and fleshy (drupes, berries or berry-like), or dehiscent and dry (capsules), or rarely indehiscent and dry or splitting into fruit portions (mericarps), or winged; in some taxa the (ovaries and) fruits of 2 or more individual flowers united to form typically ovoid to subglobular syncarps. Seeds discrete or in pyrenes (encased by its testa fused with an endocarp layer), sometimes variously winged, endosperm entire or ruminate, embryo straight or curved, often tiny. Distribution. Widespread, present on all continents, but predominantly tropical, with 614 genera and 13,150 species counted (Davis et al., Ann. Missouri Bot. Gard. 96 (2009) 68-78), and so globally the fourth largest flowering-plant family after Orchidaceae, Asteraceae and Fabaceae (Robbrecht, Opera Bot. Belg. 1 (1988) 1-271). The family is particularly diverse in tropical and subtropical America, tropical Africa and Madagascar, Southeast Asia and the southwestern Pacific (Davis et al., Ann. Missouri Bot. Gard. 96 (2009) 68-78). Although many (211) genera are monotypic and over 70% have fewer than 10 species, some are sizeable in terms of number of species, such as Psychotria L. (the largest genus with 1834 species; also the third largest angiosperm genus), Ixora L. (c. 530 species), Pavetta L. (c. 357 species), Ophiorrhiza L. (c. 317 species), Timonius DC. (c. 250 species, estimate here is based on recent confirmation of some 100 species present in Borneo alone), or Lasianthus Jack (c. 228 species). The majority of species have restricted distributions. Davis et al. (Ann. Missouri Bot. Gard. 96 (2009) 68-78) suggest that many Rubiaceae are consequently vulnerable to extinction. For Southeast Asia, they identify New Guinea (with large landmass, high topography and extreme physiographic differentiation), the Philippines (an archipelago of numerous islands with topographic and edaphic variation and relative isolation), and Borneo (also with large landmass and much edaphic and topographic variation) as among the world's top five areas with the highest number of endemic Rubiaceae species. In Singapore 52 genera and 150 species are considered native and another 8 species are exotic but known to have naturalised. By our latest reckoning, 50 species (c. 33%) are presumed Nationally Extinct. Ecology. The majority are lowland taxa, but a number of genera (such as Argostemma Wall., Ophiorrhiza) are richer at mid-to montane elevations. This, however, does not apply to Singapore; Ophiorrhiza has but a single species and Argostemma is absent. Ridley (J. Straits Branch Roy. Asiat. Soc. 33 (1900) 90) was sceptical that three Argostemma collections labelled Singapore by Lobb were correctly attributed. In this relatively small and topographically limited area, even predominantly forest understorey groups such as Psychotria, Lasianthus and Urophyllum Wall. are more species-rich than a number of big-tree genera, especially those dispersed by wind.
Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kom... more Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kompleks ( Rubiaceae ) di Malesia, dengan tiga jenis baru. Floribunda 5(8): 323–331. —. Psydrax dicoccos Gaertn., merupakan jenis tipe dari Psydrax Gaertn., hanya mempunyai dua sampel buah sebagai bahan tipenya. Terbatasnya material tipe menghasilkan kesalahan yang menyebabkan jenis yang berbeda diberikan nama P. dicoccos. Sebanyak 140 lembar spesimen herbarium yang diidentifikasi sebagai P. dicoccos di kawasan Malesia, ditentukan sebagai takson yang berbeda dan ditunjukkan dengan tiga jenis baru yaitu Psydrax elmerianus, P. koordersianus dan P. sumatranus. Diagnostik karakter masing-masing jenis disediakan. Kata Kunci: Malesia, jenis baru, Psydrax . Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. The Psydrax dicoccos Complex ( Rubiaceae ) in Malesia, with Three New Species. Floribunda 5(8): 323–331. — . Psydrax dicoccos Gaertn., the type species of Psydrax Ga...
Species radiations have long fascinated biologists, but the contribution of adaptation to observe... more Species radiations have long fascinated biologists, but the contribution of adaptation to observed diversity and speciation is still an open question. Here, we explore this question using the clove genus, Syzygium, the world’s largest genus of tree species comprising approximately 1200 species. We dissect Syzygium diversity through shotgun sequencing of 182 distinct species and 58 additional as-yet unidentified taxa, and assess their genetic diversity against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that Syzygium grande shares a whole genome duplication (WGD) event with other Myrtales. Genomic analyses confirm that Syzygium originated in Sahul (Australia-New Guinea), and later diversified eastward to the Hawaiian Islands and westward in multiple independent migration events. The migrations were associated with bursts of speciation events, visible by poorly resolved branches on phylogenies and networks, some of which were likely confounded by inc...
WONG, K. M. & MAHYUNI, R. 2018. Flora of Singapore Precursors, 2. A new species and two new combi... more 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.
The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. Howev... more The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. However, during a visit in April 2013 three populations are located close together with more than twenty buds and some rotting blooming flowers, Tetrastigma sp. was detected. Field observations could be made and material was collected for comparison with that in the Herbarium Bogoriense (BO). It was concluded that they are R. gadutensis Meijer, which is known from Padang, Ulu Gadut. Notes on its morphology are given. The distribution of species is discussed.
Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan... more Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan Selatan National Park, Province of Lampung. The study sites was focused on secondary lowland forests of Way Canguk and Sukaraja Atas. The research was aimed to obtain floristic data from such areas that has never been recorded. Flora diversity in these areas is relatively high as represented by 183 plant species from 124 genera and 60 families. It is noted that 3 species are newly for Sumatran flora.
Sumatra is described. The species was previously recorded as either R. arnoldi or R. atjehensis, ... more Sumatra is described. The species was previously recorded as either R. arnoldi or R. atjehensis, but it is distinguished by the absence of windows, the large undulating exterior annulus, the short pubescence on the upper surface of perigone lobes, and the very wide of diaphragm opening. A key to species of Sumatran Raffesia is provided.
Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos... more Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kompleks ( Rubiaceae ) di Malesia, dengan tiga jenis baru. Floribunda 5(8): 323–331. —. Psydrax dicoccos Gaertn., merupakan jenis tipe dari Psydrax Gaertn., hanya mempunyai dua sampel buah sebagai bahan tipenya. Terbatasnya material tipe menghasilkan kesalahan yang menyebabkan jenis yang berbeda diberikan nama P. dicoccos. Sebanyak 140 lembar spesimen herbarium yang diidentifikasi sebagai P. dicoccos di kawasan Malesia, ditentukan sebagai takson yang berbeda dan ditunjukkan dengan tiga jenis baru yaitu Psydrax elmerianus, P. koordersianus dan P. sumatranus. Diagnostik karakter masing-masing jenis disediakan. Kata Kunci: Malesia, jenis baru, Psydrax . Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. The Psydrax dicoccos Complex ( Rubiaceae ) in Malesia, with Three New Species. Floribunda 5(8): 323–331. — . Psydrax dicoccos Gaertn., the type species of Psydrax Gaertn., is typified by a specimen consisting of two detached fruits. The limited type material has resulted in a number of distinct species being wrongly referred to that species. Approximately 140 herbarium specimens identified as P. dicoccos in the Malesian region are shown to represent three new species, Psydrax elmerianus, P. koordersianus and P. sumatranus. The diagnostic characteristics of these species are provided. Keywords: Malesia, new species, Psydrax .
Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan... more Study on plant diversity by exploration and collection have been carried out at the Bukit Barisan Selatan National Park, Province of Lampung.The study sites was focused on secondary lowland forests of Way Canguk and Sukaraja Atas. The research was aimed to obtain floristic data from such areas that has never been recorded. Flora diversity in these areas is relatively high as represented by 183 plant species from 124 genera and 60 families. It is noted that 3 species are newly for Sumatran flora.
Canthium longipetalum Y.H.Tan & S.S.Zhou in Yang et al. (2019: 197) is a species of Rubiaceae rec... more Canthium longipetalum Y.H.Tan & S.S.Zhou in Yang et al. (2019: 197) is a species of Rubiaceae recently described from northern Myanmar. This species was identified as belonging to the Vanguerieae tribe, and was placed provisionally in the genus Canthium Lamarck (1783: 602) based on morphological characters including the presence of axillary inflorescences, valvate corolla aestivation, two-locular ovaries, and a two-lobed stigma (Yang et al. 2019). However, the suite of characters cited by the authors to support the placement of their species in Canthium define an overly broad and now-superseded concept of the genus.
Ramentae are hair-like structures found on the perigone tube and diaphragm in species of Rafflesi... more Ramentae are hair-like structures found on the perigone tube and diaphragm in species of Rafflesia (Rafflesiaceae). Although ramenta morphology provides an important taxonomic character, a consistent terminology has not been used in species descriptions. As such, morphological comparisons among species as well as among populations within a species are difficult. We used a variety of resources to document the morphology including the location and density of ramenta among 18 species of Rafflesia and between populations and/or sexes of two species. We identified five types of ramenta: tuberculate, filiform, swollen apex, toadstool, and fence-like and recognized several variations within each type. Ramenta types characterize four species complexes: R. patma (tuberculate), R. arnoldii (filiform), R. pricei (mostly swollen apex), and R. hasseltii (mostly toadstool). Our classification of ramenta offers a tool for using consistent terminology to re-evaluate previously described species and to define new species of Rafflesia.
Rafflesia zollingeriana Koord. was one of Rafflesia that distributed in Java. Although it has bee... more Rafflesia zollingeriana Koord. was one of Rafflesia that distributed in Java. Although it has been stated as a different species, R. zollingeriana is sometimes still regarded as a synonym of R. patma. In addition, there are several contradictions in description of R. zollingeriana. Therefore, further investigation is needed. This study attempts presents a full the description of the R. zollingeriana female flower. In this study, a full description of female flower of R. zollingeriana and pictures of important characters such as ramenta, annulus, perigone lobes, disc, processes, bractea are presented. This study is also compared the morphology of R. zollingeriana and R. patma, to confirm their differences in size, opening of diaphragm, blotches and warts pattern on perigone lobes and diaphragm, annulus, and ramenta.
The plant in the collection of C. Hose 751 is somewhat stouter as hitherto known, with the leaf b... more The plant in the collection of C. Hose 751 is somewhat stouter as hitherto known, with the leaf blade ca. 20 by 17.5 cm and the male peduncle ca. 15 cm long. Female flowers of this species are still not known. (2) RE-DESCRIPTION OF TRICHOSANTHES CELEBICA Cogn. When conceiving T. celebica Cogn. (1881: 385) for the revision of Trichosanthes (Rugayah, 1999; de Wilde & Duyfjes, 2010), it was assumed that the following four collections from E. Sulawesi: Beccari 51 (type, consisting of a male specimen and one fruit), Kjellberg 1212 (male, BO, S, not seen by de Wilde at the time, though recently we could examine and identify the S-duplicate as T. tricuspidata Lour.), de Vogel 6136 (fruit), and de Wilde & Duyfjes 21903 (sterile), and one from Buru: Nooteboom 5275 (sterile) all belonged to that species. With recent molecular sequencing of the collection of de Vogel 6136, as part of a larger molecular analysis of the whole genus Trichosanthes
MAHYUNI, R., KUSUMA,Y. W. C., WIHERMANTO & VELDKAMP, J. F. 2015. Notes on Rafflesia (Rafflesiacea... more MAHYUNI, R., KUSUMA,Y. W. C., WIHERMANTO & VELDKAMP, J. F. 2015. Notes on Rafflesia (Rafflesiaceae) in Sumatra with a new record Rafflesia gadutensis Meijer. Reinwardtia 14(2): 317 - 322. Pulau Mursala is a small island west of the Sibolga, Tapanuli Tengah District, North Sumatra, Indonesia. The occurrence of the genus Rafflesia (Rafflesiaceae) there has never been reported before. However, during a visit in April 2013 three populations are located close together with more than twenty buds and some rotting blooming flowers, Tetrastigma sp. was detected. Field observations could be made and material was collected for comparison with that in the Herbarium Bogoriense (BO). It was concluded that they are R.gadutensis Meijer, which is known from Padang, Ulu Gadut. Notes on its morphology are given. The distribution of species is discussed.
MAHYUNI, R., CHIKMAWATI, T., ARIYANTI, N. S. & KUSUMAWATY, A. 2022. A new variety of Canthiumera ... more MAHYUNI, R., CHIKMAWATI, T., ARIYANTI, N. S. & KUSUMAWATY, A. 2022. A new variety of Canthiumera glabra (Rubiaceae: Vanguerieae). Reinwardtia 21(1): 13‒17. — Canthiumera glabra var. laxiflora (Rubiaceae: Vanguerieae), a new variety from Java and Sumatra is described. The new variety differs from the typical variety in having laxly branched inflorescences and is restricted to south Sumatra (Lampung) and southwestern Java.
typically valvate or contorted, sometimes imbricate in bud; stamens usually as many as and altern... more typically valvate or contorted, sometimes imbricate in bud; stamens usually as many as and alternating with corolla lobes, in heterostylous flowers typically occurring at different levels in the corolla throat of the different morphs; filaments inconspicuous or long; anthers dorsi-or basifixed, introrse, thecae 2, dehiscing lengthwise, rarely with apical pores; ovary basically inferior, rarely becoming (half-)superior during fruit development, syncarpous, locules (1−)2 or sometimes more, nectar-secreting disk often present at ovary apex; placentas axile, parietal, basal or apical; ovules 1−many in each locule, mostly anatropous; style mostly simple, rarely divided into branches; stigmas capitate, clavate or 2-to several-lobed. Fruits small or large, indehiscent and fleshy (drupes, berries or berry-like), or dehiscent and dry (capsules), or rarely indehiscent and dry or splitting into fruit portions (mericarps), or winged; in some taxa the (ovaries and) fruits of 2 or more individual flowers united to form typically ovoid to subglobular syncarps. Seeds discrete or in pyrenes (encased by its testa fused with an endocarp layer), sometimes variously winged, endosperm entire or ruminate, embryo straight or curved, often tiny. Distribution. Widespread, present on all continents, but predominantly tropical, with 614 genera and 13,150 species counted (Davis et al., Ann. Missouri Bot. Gard. 96 (2009) 68-78), and so globally the fourth largest flowering-plant family after Orchidaceae, Asteraceae and Fabaceae (Robbrecht, Opera Bot. Belg. 1 (1988) 1-271). The family is particularly diverse in tropical and subtropical America, tropical Africa and Madagascar, Southeast Asia and the southwestern Pacific (Davis et al., Ann. Missouri Bot. Gard. 96 (2009) 68-78). Although many (211) genera are monotypic and over 70% have fewer than 10 species, some are sizeable in terms of number of species, such as Psychotria L. (the largest genus with 1834 species; also the third largest angiosperm genus), Ixora L. (c. 530 species), Pavetta L. (c. 357 species), Ophiorrhiza L. (c. 317 species), Timonius DC. (c. 250 species, estimate here is based on recent confirmation of some 100 species present in Borneo alone), or Lasianthus Jack (c. 228 species). The majority of species have restricted distributions. Davis et al. (Ann. Missouri Bot. Gard. 96 (2009) 68-78) suggest that many Rubiaceae are consequently vulnerable to extinction. For Southeast Asia, they identify New Guinea (with large landmass, high topography and extreme physiographic differentiation), the Philippines (an archipelago of numerous islands with topographic and edaphic variation and relative isolation), and Borneo (also with large landmass and much edaphic and topographic variation) as among the world's top five areas with the highest number of endemic Rubiaceae species. In Singapore 52 genera and 150 species are considered native and another 8 species are exotic but known to have naturalised. By our latest reckoning, 50 species (c. 33%) are presumed Nationally Extinct. Ecology. The majority are lowland taxa, but a number of genera (such as Argostemma Wall., Ophiorrhiza) are richer at mid-to montane elevations. This, however, does not apply to Singapore; Ophiorrhiza has but a single species and Argostemma is absent. Ridley (J. Straits Branch Roy. Asiat. Soc. 33 (1900) 90) was sceptical that three Argostemma collections labelled Singapore by Lobb were correctly attributed. In this relatively small and topographically limited area, even predominantly forest understorey groups such as Psychotria, Lasianthus and Urophyllum Wall. are more species-rich than a number of big-tree genera, especially those dispersed by wind.
Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kom... more Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. Psydrax dicoccos kompleks ( Rubiaceae ) di Malesia, dengan tiga jenis baru. Floribunda 5(8): 323–331. —. Psydrax dicoccos Gaertn., merupakan jenis tipe dari Psydrax Gaertn., hanya mempunyai dua sampel buah sebagai bahan tipenya. Terbatasnya material tipe menghasilkan kesalahan yang menyebabkan jenis yang berbeda diberikan nama P. dicoccos. Sebanyak 140 lembar spesimen herbarium yang diidentifikasi sebagai P. dicoccos di kawasan Malesia, ditentukan sebagai takson yang berbeda dan ditunjukkan dengan tiga jenis baru yaitu Psydrax elmerianus, P. koordersianus dan P. sumatranus. Diagnostik karakter masing-masing jenis disediakan. Kata Kunci: Malesia, jenis baru, Psydrax . Ridha Mahyuni, Tatik Chikmawati, Nunik Sri Ariyanti & Khoon Meng Wong. 2018. The Psydrax dicoccos Complex ( Rubiaceae ) in Malesia, with Three New Species. Floribunda 5(8): 323–331. — . Psydrax dicoccos Gaertn., the type species of Psydrax Ga...
Species radiations have long fascinated biologists, but the contribution of adaptation to observe... more Species radiations have long fascinated biologists, but the contribution of adaptation to observed diversity and speciation is still an open question. Here, we explore this question using the clove genus, Syzygium, the world’s largest genus of tree species comprising approximately 1200 species. We dissect Syzygium diversity through shotgun sequencing of 182 distinct species and 58 additional as-yet unidentified taxa, and assess their genetic diversity against a chromosome-level reference genome of the sea apple, Syzygium grande. We show that Syzygium grande shares a whole genome duplication (WGD) event with other Myrtales. Genomic analyses confirm that Syzygium originated in Sahul (Australia-New Guinea), and later diversified eastward to the Hawaiian Islands and westward in multiple independent migration events. The migrations were associated with bursts of speciation events, visible by poorly resolved branches on phylogenies and networks, some of which were likely confounded by inc...
WONG, K. M. & MAHYUNI, R. 2018. Flora of Singapore Precursors, 2. A new species and two new combi... more 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.
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