
Richard M. K. Saunders- BSc, MSc, PhD
- Professor (Honorary) at The University of Hong Kong
Richard M. K. Saunders
- BSc, MSc, PhD
- Professor (Honorary) at The University of Hong Kong
About
240
Publications
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Introduction
Systematics and phylogenetics of flowering plants, involving an integrated approach to descriptive taxonomy, phylogenetic reconstruction and biogeography, based on morphological and molecular data; plant reproductive biology, including phenology, pollination ecology, and assessments of breeding systems
Current institution
Publications
Publications (240)
Several evolutionary lineages in the early divergent angiosperm family Annonaceae possess flowers with a distinctive pollinator trapping mechanism, in which floral phenological events are very precisely timed in relation with pollinator activity patterns. This contrasts with previously described angiosperm pollinator traps, which predominantly func...
Background and aims:
Mycorrhizal associations in mycoheterotrophic plants are generally more specialized than in autotrophs. Mycoheterotrophs typically bear small, inconspicuous flowers that often self-pollinate to maximize seed set, although some have structurally complex flowers indicative of xenogamy. A trade-off has previously been proposed be...
A major goal of phylogenetic systematics is to understand both the patterns of diversification and the processes by which these patterns are formed. Few studies have focused on the ancient, species-rich Magnoliales clade and its diversification pattern. Within Magnoliales, the pantropically distributed Annonaceae are by far the most genus-rich and...
Potential key functional floral traits are assessed in the species‐rich early divergent angiosperm family Annonaceae. Pollinators (generally beetles) are attracted by various cues (particularly visual, olfactory and thermogenic), with pollinators rewarded by nectar (generally as stigmatic exudate), heat and protection within the partially enclosed...
Aim African–Asian disjunctions are common in palaeotropical taxa, and are typically explained by reference to three competing hypotheses: (1) ‘rafting’ on the Indian tectonic plate, enabling Africa-to-Asia dispersal; (2) migration via Eocene boreotropical forests; and (3) transoceanic long-distance dispersal. These hypotheses are tested using Uvari...
Most species in the early divergent angiosperm family Annonaceae are apocarpous, with very diverse gynoecial morphologies. Although several Annonaceae genera with apocarpous flowers are known to possess an extragynoecial compitum (EGC) that enables intercarpellary pollen-tube growth to enhance fertilization success, the occurrence of EGC across the...
Mycoheterotrophs are non‐photosynthetic plants that obtain all of their carbon requirements through parasitizing mycorrhizal fungi. They originated from the autotrophic ancestors and usually have more specific relationships with fungi than that of green plants, for reasons that are largely unknown. Determining the factors that lead to specificity i...
Floral mimics deceive their pollinators by developing visual and olfactory resemblance to various models. We report a flower that exhibits phenotypes like aerial litter and deceives an aerial litter specialist beetle to achieve pollination.
We assessed the floral phenology and the effective pollinators of an Australian understorey treelet, Meiogyne...
Meiogyne is a genus of trees and treelets occurring in Indomalaya and Australasia-Pacific, an unusually wide distribution across Australasia and Western Pacific compared to the rest of the family Annonaceae. Previous chloroplast phylogenies of the genus offered poor resolution and support for many internal nodes. Here, a molecular phylogeny was rec...
Fungi are widely known for their pathological impact on flowers, but some play a beneficial role in pollination. We report a case of tripartite pollination system in the flowering plant Meiogyne hainanensis (Annonaceae) in Hainan, China. The flowers emit a fruity scent composed of a mixture of mostly sesquiterpenes and aliphatic esters, attracting...
Premise
The family Annonaceae possesses a broad array of floral phenotypes and pollination specialisations, and are important in the plant-pollinator interactions of tropical rainforests. Although there has been considerable effort to assess their interactions with pollinators, attempts to characterise their visual and olfactory communication chann...
Floral mimics deceive their pollinators by developing visual and olfactory resemblance to their models. Our knowledge on the diversity of models is expanding rapidly. We report a system in which the flowers exhibit phenotypes similar to aerial litter and deceives an aerial litter specialist beetle to achieve pollination.
We assessed the floral phen...
Tropical forests harbor the richest biodiversity among terrestrial ecosystems, but few studies have addressed the underlying processes of species diversification in these ecosystems. We use the pantropical flowering plant family Annonaceae as a study system to investigate how climate and biogeographic events contribute to diversification. A super-m...
A new species is described from New Caledonia in the genus Goniothalamus, which now includes three endemic species from the archipelago. The new species was first collected over 150 years ago, but had not been subsequently studied until now. Material of the New Caledonian taxa was included in a recent molecular phylogeny, which shows that they are...
Aim
Tropical rainforests harbour the richest biodiversity among terrestrial ecosystems, but few studies have addressed underlying processes of species diversification in these ecosystems. We use the pantropical and early divergent flowering plant family Annonaceae as a model system to investigate how abiotic factors such as climate and biogeographi...
Three new Mitrephora species (Annonaceae), M. langsuanensis sp. nov., M. sirindhorniae sp. nov. and M. sukhothaiensis sp. nov., are described from Thailand. Mitrephora langsuanensis resembles M. macclurei, but its leaves have more secondary veins, and its flowers have more carpels, with yellow-and-pink striped outer petals with a margin that become...
A checklist of all species of bryophytes, lycophytes, ferns, gymnosperms
and angiosperms that are found in the wild (native, naturalised and casual) in Singapore is
presented. We have attempted to account for all names of species and infraspecific taxa that
have ever been recorded for Singapore, along with the pertinent publications that reported e...
A checklist of all species of bryophytes, lycophytes, ferns, gymnosperms and angiosperms that are found in the wild (native, naturalised and casual) in Singapore is presented. We have attempted to account for all names of species and infraspecific taxa that have ever been recorded for Singapore, along with the pertinent publications that reported e...
A checklist of all species of bryophytes, lycophytes, ferns, gymnosperms and angiosperms that are found in the wild (native, naturalised and casual) in Singapore is presented. We have attempted to account for all names of species and infraspecific taxa that have ever been recorded for Singapore, along with the pertinent publications that reported e...
A checklist of all species of bryophytes, lycophytes, ferns, gymnosperms and angiosperms that are found in the wild (native, naturalised and casual) in Singapore is presented. We have attempted to account for all names of species and infraspecific taxa that have ever been recorded for Singapore, along with the pertinent publications that reported e...
The majority of tribe Phyllantheae (Phyllanthaceae) is currently placed in the paraphyletic genus Phyllanthus and discussions have persisted on how to resolve this issue. Here, we split Phyllanthus into ten monophyletic genera, which are all reinstatements of former genera, but with changes made to the circumscription and constituent species of eac...
Evolutionary slowdowns in diversification have been inferred in various plant and animal lineages. Investigation based on diversification models integrated with environmental factors and key characters could provide critical insights into this diversification trend. We evaluate diversification rates in the Cirrhopetalum alliance (Bulbophyllum, Orch...
Recent taxonomic and floristic accounts list Kadsura scandens (Blume) Blume as the sole native Kadsura species in Singapore. However, these works have overlooked Ridley's earlier documentation of another species, Kadsura verrucosa (Gagnep.) A.C.Sm., which was recorded under the misapplied name K. cauliflora. The reduction of Kadsura cauliflora to a...
Two new Goniothalamus species (Annonaceae), G. roseipetalus sp. nov. and G. sukhirinensis sp. nov., are described from the southern limits of Peninsular Thailand (Narathiwat and Yala Provinces). Both new species resemble G. macrophyllus, G. scortechinii and G. uvarioides. The addition of these two new species brings the total number of Goniothalamu...
Work toward completion of the Annonaceae treatment for the Flora of Thailand revealed 18 species previously unrecorded for the country, six of them in the genus Fissistigma. In addition, several species previously placed in synonymy are re-instated, for which we propose three new combinations in the genera Mitrella, Monoon, and Sphaerocoryne.
Breakdown of self-incompatibility increases opportunities for both self-fertilization and interspecific hybridization, although the latter is dependent on the extent of competition between heterospecific and conspecific pollen. We investigate the mating system and pollination biology of five phylogenetically closely related species within a distylo...
Mycoheterotrophic plants (MHPs) growing on arbuscular mycorrhizal fungi (AMF) usually maintain specialized mycorrhizal associations. The level of specificity varies between MHPs, although it remains largely unknown whether interactions with mycorrhizal fungi differ by plant lineage, species, and/or by population. Here, we investigate the mycorrhiza...
The genus Phyllanthus is paraphyletic as currently circumscribed, with the genera Breynia, Glochidion and Synostemon nested within it. A phylogeny based on nuclear (ITS, PHYC) and chloroplast (matK, accD-psaI, trnS-trnG) markers is presented, including 18/18 subgenera and 53/70 sections. Differences in habit, branching type, floral and fruit charac...
The genus Polyalthia (Annonaceae) has undergone dramatic taxonomic changes in recent years. Nine Polyalthia species have historically been recognized in Fiji, all of which have subsequently been transferred to three different genera, viz. Goniothalamus, Huberantha and Meiogyne. The transfer of six of these species has received strong molecular phyl...
Friesodielsia (Annonaceae; Uvarieae) was erected by Van Steenis (1948: 458) to replace the illegitimate name Oxymitra (Blume 1830: 71) Hooker & Thomson (1855: 145), which was a later homonym of the liverwort Oxymitra Bischoff in Lindenberg (1829: 124). Although Van Steenis recognized 52 species in Friesodielsia from Africa and Asia, many taxonomist...
Dispersal syndromes are often defined by reference to fruit traits that are associated with distinct frugivore guilds. Studies rarely examine the relationship between seed traits and frugivores or test the alternative hypothesis that traits are shaped by climatic variables. We assess whether the evolution of seed size and physical defence are corre...
Artabotrys comprises a species-poor early divergent grade (EDG) and a main species-rich clade ("main Artabotrys clade," MAC). All members of the MAC exhibit a remarkably well-conserved floral Bauplan characterized by a tightly enclosed floral chamber with an elaborate rim between the inner petal blade and claw. Conversely, EDG resembles the sister...
The Cirrhopetalum alliance is a loosely circumscribed species-rich group within the mega-diverse genus Bulbophyllum (Orchidaceae). The monophyletic status of the alliance has been challenged by previous studies, although established sectional classifications have yet to be tested in a phylogenetic context. We used maximum likelihood and Bayesian an...
Gnetum possesses morphologically bisexual but functionally unisexual reproductive structures that exude sugary pollination drops to attract insects. Previous studies have revealed that the arborescent species (G. gnemon L.) and the lianoid species (G. luofuense C.Y.Cheng) possess different pollination syndromes. This study compared the proteome in...
Aim
The biogeographical and habitat history of the species‐rich angiosperm genus Artabotrys is reconstructed to assess hypotheses relating to processes that underlie palaeotropical intercontinental disjunction (PID) and regional diversification patterns.
Location
Palaeotropics.
Taxon
Artabotrys (Annonaceae).
Methods
Phylogenetic relationships we...
We review the species diversity of the Asian genus Meiogyne (Annonaceae) in Thailand. Four new species, M. anomalocarpa, M. chiangraiensis, M. gardneri, and M. maxiflora, are described. Meiogyne anomalocarpa has the widest distribution of any Meiogyne species in Thailand, but the other three species are narrowly distributed. Meiogyne anomalocarpa a...
Background
A major goal of phylogenetic systematics is to understand both the patterns of diversification and the processes by which these patterns are formed. Few studies have focused on the ancient, species-rich Magnoliales clade and its diversification pattern. Within Magnoliales, the pantropically distributed Annonaceae are by far the most genu...
A new species, Mitrephora monocarpa R.M.K.Saunders & Chalermglin, sp. nov. (Annonaceae), is described from Surat Thani Province in Peninsular Thailand. It resembles two other species, M. alba Ridl. and M. keithii Ridl., with which it is broadly sympatric, but can be distinguished by its solitary flowers (not borne in thyrsoid inflorescences as in m...
Hong Kong possesses an impressively diverse tree flora with 390 native species. This book celebrates the incredible diversity, beauty and biology of the territory's tree species, highlighting over 100 important species that are individually illustrated in exquisitely detailed watercolour paintings by Sally Grace Bunker, an acclaimed botanical artis...
Recent molecular and morphological studies have clarified generic circumscriptions in Annonaceae tribe Miliuseae and resulted in the segregation of disparate elements from the previously highly polyphyletic genus Polyalthia s.l. Several names in Polyalthia nevertheless remain unresolved, awaiting assignment to specific genera, including Polyalthia...
Artabotrys scortechinii King was recently discovered as a new record for the native flora of Singapore. This poorly known species has been confused with Artabotrys maingayi Hook.f. & Thomson and its fruits and seeds have not been previously described. This paper presents an augmented description, including its fruit morphology and diagnostic floral...
Although hybridisation between closely related species is common and known to be important in plant evolution, hybridisation at the generic level or above is comparatively rare. We address ancient intergeneric hybridisation in the early-divergent angiosperm family Annonaceae by phylogenetic reconstruction, divergence time estimation and coalescent...
The Dasymaschalon alliance within the early divergent angiosperm family Annonaceae comprises c. 180 species in four genera (Dasymaschalon, Desmos, Friesodielsia, and Monanthotaxis). The alliance offers an excellent opportunity for investigating perianth evolution and functional adaptations because of the presence of different numbers of petal whorl...
Parsimony ancestral character reconstructions for the Desmos–Dasymaschalon–Friesodielsia clade. (A) Number of petal whorls. (B) Pollination chamber type. (C) Connivence of outer petals in flower buds. (D) Opening of outer petals during anthesis. Character reconstructions across 10,000 Bayesian input trees are summarized and mapped on the 50% majori...
Taxon-character data matrix used for ancestral character-state reconstructions. (i) number of petal whorls: 0 = one whorl; 1 = two whorls; (ii) pollination chamber type: 0 = pollination chamber absent, with petals spreading or loosely coherent; 1 = partially closed pollination chamber formed by basally constricted petals, with an apical aperture an...
Two new species of Artabotrys are described from Thailand. Artabotrys tanaosriensis J.Chen, Chalermglin & R.M.K.Saunders, sp. nov., is similar to A. oblanceolatus Craib but differs in its symmetrical, cuneate or decurrent leaf base, externally distinct outer petal blades and claws, deltoid and undulate outer petal blades, rhomboid and undulate inne...
Aim
The historical biogeography of the species‐rich flowering plant genus Goniothalamus ( c . 130 species) and the wider Annonaceae tribe Annoneae is investigated to evaluate hypotheses regarding the processes underlying tropical intercontinental disjunctions (‘long‐distance dispersal [ LDD ]’ versus ‘boreotropics’) and floristic exchange between b...
Although 'dry-type' stigmas are widely regarded as ancestral in angiosperms, the early-divergent family Annonaceae has copious stigmatic exudate. We evaluate three putative functions for this exudate: as a nutritive reward for pollinators; as a pollen germination medium; and as an extragynoecial compitum that enables pollen tube growth between carp...
Background
The Asimina-Disepalum clade (Annonaceae subfam. Annonoideae tribe Annoneae) includes a major Neotropical-Asian biogeographical disjunction. We evaluate whether this disjunction can be explained by the Eocene boreotropics hypothesis, which relies on the existence of extensive boreotropical forests during the Late Palaeocene-Early Eocene t...
The Annonaceae, the largest family in the early-divergent order Magnoliales, comprises 107 genera and c. 2,400 species. Previous molecular phylogenetic studies targeting different taxa have generated large quantities of partially overlapping DNA sequence data for many species, although a large-scale phylogeny based on the maximum number of represen...
Lineage diversification and evolution of pollinator trapping in Artabotrys (Annonaceae)
The taxonomic identity of Kadsura matsudae is reevaluated. This taxon is often treated as a synonym of K. japonica, a species known from Japan, Korea, and Taiwan. When studying the type materials of K. matsudae, however, we noted that some of its morphological characters, such as the non-contiguous thecae in adjacent stamens, do not fall within the...
Oncodostigma Diels (1912: 143) was erected by Diels (1912) based on the type species O. leptoneura Diels (1912: 143). Five additional species were subsequently added to the genus, viz.: O. wilsonii Guillaumin (1931: 224), O. monosperma (Hooker & Thomson 1872: 57) Sinclair (1951: 605), O. mindorense (Merrill 1907: 273) Bân (1974: 1779), O. hainanens...
Bulbophyllum jingdongense, a new species from South China and Laos belonging to the Cirrhopetalum alliance (Orchidaceae), is described and illustrated. It is morphologically distinct from all other known species in the alliance on account of the following diagnostic characters: pseudobulbs compressed subglobose; sepals and petals with dense, reddis...
Vegetative propagation (clonal growth) conveys several evolutionary advantages that positively affect life history fitness and is a widespread phenomenon among angiosperms that also reproduce sexually. However, a bias towards clonality can interfere with sexual reproduction and lead to sexual extinction, although a dearth of effective genetic tools...
Alphonsea glandulosa sp. nov. is described from Yunnan Province in south-west China. It is easily distinguished from all previously described Alphonsea species by the possession of glandular tissue at the base of the adaxial surface of the inner petals. Nectar was observed throughout the flowering period, including the pistillate phase and subseque...
GenBank accession numbers and voucher information for the materials used in this study.
(XLSX)
Friesodielsia and the closely related genera Dasymaschalon, Desmos, Exellia, Gilbertiella and Monanthotaxis (Annonaceae subfamily Annonoideae tribe Uvarieae) are taxonomically problematic, with obscure generic delimitations and poorly known phylogenetic relationships. The present study addresses the polyphyletic status of Friesodielsia, using two n...
The floral phenology, pollination ecology and breeding systems of two sympatric early-divergent angiosperms, Goniothalamus tapisoides and G. suaveolens (Annonaceae) are compared. The flowers are protogynous and morphologically similar, with anthesis over 23–25 h. Both species are predominantly xenogamous and pollinated by small beetles: G. tapisoid...
Disepalum comprises two monophyletic sister subgenera, Enicosanthellum and Disepalum, with strikingly different floral morphologies: the former has two whorls of unfused sepals, forming a partially enclosed floral chamber, whereas the latter possesses a single whorl of congenitally fused petals and lacks a floral chamber. The pollination ecologies...
Taxonomic delimitation of Disepalum (Annonaceae) is contentious, with some researchers
favoring a narrow circumscription following segregation of the genus Enicosanthellum. We
reconstruct the phylogeny of Disepalum and related taxa based on four chloroplast and two
nuclear DNA regions as a framework for clarifying taxonomic delimitation and assessi...
Voucher information and GenBank accession numbers for samples used in this study.
(DOCX)
List of primers used for amplification and sequencing of the four cpDNA (matK, trnL-F, ndhF and ycf1) and two nDNA (AP3 and phyA) regions.
(DOCX)
List of protocols used to amplify the four cpDNA (matK, trnL-F, ndhF and ycf1) and two nDNA (AP3 and phyA) regions.
(DOCX)
Bayesian 50% majority-rule consensus tree based on combined nDNA (AP3 and phyA) sequence data partitioned according to DNA region identity.
Numbers at nodes indicate MP, ML bootstrap values (> 50%) and Bayesian posterior probabilities (> 95%). Bootstrap values < 50% are indicated by ‘-’. Scale bar: 0.02 substitutions per site.
(TIF)
Bayesian 50% majority-rule consensus tree based on combined cpDNA (matK, trnL-F, ndhF and ycf1) sequence data partitioned according to DNA region identity.
Numbers at nodes indicate MP, ML bootstrap values (> 50%) and Bayesian posterior probabilities (> 95%). Bootstrap values < 50% are indicated by ‘-’. Scale bar: 0.02 substitutions per site.
(TIF)