Wu Zhengyi and his contributions to plant taxonomy and phytogeography

Wu Zhengyi,a master in science and a giant in botany,was born in Jiujiang,Jiangxi province,China 100 years ago and passed away on June 20,2013 in Kunming,China.He was an Academician of the Chinese Academy of Sciences,Professor and Director Emeritus of Kunming Institute of Botany,Chinese Academy of Sciences。

A New Species of Rhodoleia(Hamamelidaceae) from the Upper Pliocene of West Yunnan, China and Comments on Phytogeography and Insect Herbivory

In Europe, fossil fruits and seeds of Rhodoleia（Hamamelidaceae） have been described from the Upper Cretaceous to the Miocene, whereas no fossil record of Rhodoleia has been reported in Asia, where the modern species occur.Herein, 21 fossil leaves identified as Rhodoleia tengchongensis sp.nov.are described from the Upper Pliocene of Tengchong County, Yunnan Province, Southwest China.The fossils exhibit elliptic lamina with entire margins, simple brochidodromous major secondary veins, mixed percurrent intercostal tertiary veins, and looped exterior tertiaries.The leaf cuticle is characterized by pentagonal or hexagonal cells, stellate multicellular trichomes, and paracytic stomata.The combination of leaf architecture and cuticular characteristics suggests that the fossil leaves should be classified into the genus Rhodoleia.The fossil distributions indicate that the genus Rhodoleia might originate from Central Europe, and that migrated to Asia prior to the Late Pliocene.Additionally, insect damage is investigated, and different types of damage, such as hole feeding, margin feeding, surface feeding, and galling, are observed on the thirteen fossil leaves.Based on the damage frequencies for the fossil and extant leaves, the specific feeding behavior of insects on Rhodoleia trees appears to have been established as early as the Late Pliocene.The high occurrence of Rhodoleia insect herbivory may attract the insect-foraging birds, thereby increasing the probability of pollination.

A novel seed cone of Pinus from the Miocene of coastal Southeast China indicates kinship with Southeast Asian pines

Pinus is an economically and ecologically important genus whose members are dominant components globally in low-latitude mountainous and mid-latitude temperate forests.Pinus species richness is currently concentrated in subtropical mid-low latitudes of the Northern Hemisphere,differing from the latitudinal diversity gradient mostly recognized in woody angiosperms.How the present pattern was developing in Earth's past is still poorly studied,particularly in eastern Asia.Here,a new fossil species,Pinus shengxianica sp.nov.is described based on a fossil seed cone from the Late Miocene Shengxian Formation in Zhejiang,southeast China.A co-occurring cone is recognized as a known fossil species,Pinus speciosa Li.Extensive comparison of extant and fossil members of Pinus suggests P.shengxianica shares a striking cone similarity to Pinus merkusii and Pinus latteri(subsection Pinus)from tropical Southeast Asia in having annular bulges around the umbo on the apophysis.The morphological resemblance indicates these two extant low-latitude pines probably possess a close affinity with the present newly-discovered P.shengxianica and originated from East Asian mid-low latitude ancestors during this generic re-diversification in the Miocene.This scenario is consistent with the evolutionary trajectory reflected by the pine fossil history and molecular data,marking the Miocene as a key period for the origin and evolution of most extant pines globally.The co-occurrences of diverse conifers and broadleaved angiosperms preferring diverse niches demonstrate Late Miocene eastern Zhejiang was one of the hot spots for coniferophyte diversity and hosted a needled-broadleaved mixed forest with complex vegetation structure and an altitudinal zonation.

Eastern Asian endemic seed plant genera and their paleogeographic history throughout the Northern Hemisphere

We review the fossil history of seed plant genera that are now endemic to eastern Asia. Although the majority of eastern Asian endemic genera have no known fossil record at all, 54 genera, or about 9%, are reliably known from the fossil record. Most of these are woody （with two exceptions）, and most are today either broadly East Asian, or more specifically confined to Sino-Japanese subcategory rather than being endemic to the Sino-Himalayan area. Of the ＂eastern Asian endemic＂ genera so far known from the fossil record, the majority formerly occurred in Europe and/or North America, indicating that eastern Asia served as a late Tertiary or Quaternary refugium for taxa. Hence, many of these genera may have originated in other parts of the Northern Hemisphere and expanded their ranges across continents and former sea barriers when tectonic and climatic conditions allowed, leading to their arrival in eastern Asia. Although clear evidence for paleoendemism is provided by the gymnosperms Amentotaxus, Cathaya, Cephalotaxus, Cunninghamia, Cryptomeria, Glyptostrobus, Ginkgo, Keteleeria, Metasequoia, Nothotsuga, Pseudolarix, Sciadopitys, and Taiwania, and the angiosperms Cercidiphyllum, Choerospondias, Corylopsis, Craigia, Cyclocarya, Davidia, Dipelta, Decaisnea, Diplopanax, Dipteronia, Emmenopterys, Eucommia, Euscaphis, Hemiptelea, Hovenia, Koelreuteria, Paulownia, Phellodendron, Platycarya, Pteroceltis, Rehderodendron, Sargentodoxa, Schizophragma, Sinomenium, Tapiscia, Tetracentron, Toricellia, Trapella, and Trochodendron, we cannot rule out the possibility that neoendemism plays an important role especially for herbaceous taxa in the present-day flora of Asia, particularly in the Sino-Himalayan region. In addition to reviewing paleobotanical occurrences from the literature, we document newly recognized fossil occurrences that expand the geographic and stratigraphic ranges previously known for Dipelta, Pteroceltis, and Toricellia.

Bamboo Leaf and Pollen Fossils from the Late Miocene of Eastern Zhejiang,China and their Phytogeological Significance

Fossil bamboo leaves and pollen from Upper Miocene deposits of the Shengxian Formation in Tiantai and Ninghai counties, eastern Zhejiang, China represent a rare record in Asia. The distinctive pseudopetiole and parallel venation of the leaf blades and the clearly thickened annulus of the pollen aperture place them in the subfamily Bambusoideae. Morphological analysis supports the determination of these fossil leaves as belonging to the genus Bambusium and two new species are described. Bambusium latipseudopetiolus Q.J. Wang et B.N. Sun sp. nov. has a distinctly wide pseudopetiole of 0.23 cm in width and 0.40 cm in length, several vascular bundles on parallel veins, and 5-8 lateral veins on both sides of the midrib. Bambusium longipseudopetiolus Q.J. Wang et B.N. Sun sp. nov. has a distinctly long pseudopetiole of 0.60 cm in length and 0.10 cm in width, several vascular bundles on the pseudopetiole, and 6 lateral veins on both sides of the midrib. Pollen grains from the same layer provide additional evidence of bamboos. They are characterized by 32.0-51.0 μm in diameter, a round pore 3.0-4.0 μm in diameter with a broad thickened annulus 2.5-3.5 μm around, and several conspicuous secondary folds on the exine surface. The morphological analysis leads to their assignment to Graminidites bambusoides Stuchlik. These fossils are important for the study of bamboo phytogeography in China. They demonstrate that there were bamboos growing in southeastern China during the Late Miocene and that bamboos in Zhejiang begin to diversify no later than the Late Miocene. In combination with bamboo fossils from other places, it seems that bamboos had a wide distribution across southern China during the Miocene, ranging from southwestern Yun＇nan to southeastern Zhejiang.

A Review on the Taxonomic,Evolutionary and Phytogeographic Studies of the Lotus Plant(Nelumbonaceae:Nelumbo)

Nelumbo Adans. （Nelumbonaceae） is an important member of the early-diverging eudicots. It contains two extant species： N. nucifera Gaertn. （the Sacred lotus）, distributed in Asia and Australia and N. lutea Willd. （the American lotus）, occurring in North America. This paper reviews the taxonomic, evolutionary and phytogeographic studies of the genus Nelumbo, and also raises scientific questions about it in further paleobotanic research. There are about 30 fossil species of Nelumbo established since the Early Cretaceous. Based on fossil studies, the ancestors of the extant N. nucifera and N. lutea are respectively considered to be N. protospeciosa from the Eocene to Miocene of Eurasia, and N. protolutea from the Eocene of North American. However, molecular systematic studies indicate that N. nucifera and N. lutea are probably split from a common ancestor during the Late Miocene to Early Pliocene, or even the Pleistocene, rather than separate relicts from extinct species on different continents. The characters of lotus stomatal development, seedling morphology as well as its flowering, pollination and fertilization in air reveal that it evolves from the land plants. Fossil data of Nelumbo indicates that the genus first occurs in mid-latitude area of Laurasia in the Early Cretaceous, then becomes widespread in North America and Eurasia and expands into Africa and South America during the Late Cretaceous; the genus probably colonizes the Indian Subcontinent from Asia during the Early Eocene after the collision of India and the Asian plates; the genus becomes extinct in Europe, but survives in Asia and North America during the Quaternary Ice Age, and later forms the present East Asia and North Australia-North America disjunctive distribution.

Researches on Plants from the Lower Devonian Xujiachong Formation in the Qujing District, Eastern Yunnan

Fossil plants Hedeia sinica Hao et Gensel 1998, Huia gracilis Wang Ct Hao2001 and Guangnania cuneata Wang et Hao are described from the Lower Devonian Xujiachong Formation,the Qujing district, eastern Yunnan, China. They contribute to our knowledge of the flora in thisdistrict. Based on the occurrence of common plants (Hedeia, Huia, Guangnania and Zosterophyllumaustralianum) and their horizons, it is proved for the first time that the mid-lower assemblage ofthe Xujiachong flora is comparable with the Early Devonian ((late) Pragian) Posongchong flora ofsoutheastern Yunnan and the upper Baragwanathia flora of Australia. In view of this fact and thestratigraphic sequence, the mid-lower part of the Xujiachong Formation is considered to be of (late)Pragian age. Through comprehensive analyses of plant, bivalve and fish assemblages and thelithology, the upper part of the Xujiachong Formation is dated to he of early Emsian age. TheXujiachong flora belonged to the northeastern Gondwana palaeophytogeographic unit during the EarlyDevonian. The early Emsian assemblage of this flora inherited the characters of the Posongchongflora and also exhibited the endemic elements. Belonging to different phytogeographic units, theXujiachong and Posongchong floras differ from the coeval flora of the Laurussian palaeocontinent.The Xujiachong flora is comparatively simple in composition, while the Posongchong flora hasabundant and highly diversified endemics. The disparity between them has resulted from the differentenvironments.

Paliurus(Paliureae,Rhamnaceae) from the Miocene of East China and its Macrofossil-based Phylogenetic and Phytogeographical History

The extant genus Paliurus Miller is divided into P. ramosissimus and P. spina-christi groups and is diagnostically characterized by distinctive orbicular-winged fruits with a trilocular （or often bilocular） ovary and basally triveined leaves with a subentire to serrate margin. Here, structurally preserved winged fruits and associated compressed leaves of Paliurus （Paliureae, Rhamnaceae） are reported from the Middle-Upper Miocene Shengxian Formation of Tiantai, Zhejiang, eastern China. The fruits can be identified as Paliurus microcarpa Xiang-Chuan Lisp. nov., the diagnostic characters of external morphology and anatomy of which differ from those of both extant and fossil generic members; the leaves can be designated as Paliurus sp. The species based on winged fruits, P. microcarpa, might represent an ancient intermediate link exclusively known across the P. ramosissimus and P. spina-christi groups, showing a closer affinity to the P. ramosissimus group based on the resemblant smaller fruits with a narrower wing, and to the P. spina-christi group based on the similar wing structure and texture, respectively. Morphological analyses of the present and previous fossil fruit records around the world indicate that diversification of Paliurus had begun in northern transpacific regions by the Late Eocene. The macrofossil records, i.e., fruits and leaves of Paliurus globally when projected on paleoenvironmental maps in view of changing continental positions through time （from Eocene to Miocene） display that the past distribution of the genus was much wider than the present and belongs to a tropical and warm temperate realm of the Northern Hemisphere. Therefore, the modern restricted disjunction in tropical and warm temperate regions of East Asia and South Europe （even eastwards West Asia） might represent glacial refugia for some of the generic ancient lineages to survive severe cold at least since the terminal Pliocene.

Woody vegetation of protected areas in northern Togo. Cases of Barkoissi, Galangashi and Oti-Keran: ecological and structure analyses of plant communities

The 170 samples obtained from ligneous investigation in Barkoissi,Galangashi and Oti-Keran protected areas（northern Togo） were subjected to floristic processing and several multivariate analyses in order to study plant diversity,life form and chorological type distribution and to classify and identify the main plant communities with their demographic structure.First,the overall life form and phytogeographical type frequencies were calculated to analyze and show the distribution of the 68 plants species in this area.Then plant communities were determined by using the hierarchical clustering with wards method.The plant communities found were identified by the technique of indicator value（IndVal）.For each grouping diversity index such as specific richness,Shannon index and Pielou＇s evenness was set out.The canonical correspondence analysis（CCA） was also used to relate the impact of environment factors and the distribution of samples.Finally the variance analysis（ANOVA） associated to post-hoc test was used to compare the similarity between the groupings.From these 170 samples,12 plant communities were discriminated,three for the reserve of Barkoissi,three for the reserve of Galangashi and six for the reserve of Oti-Keran.The samples were well distributed in the factorial plan form by axe 1 and 3 of CCA.The plant communities were distributed along the moisture gradient in the ordination.The Sudano-Zambesian species followed by Sudanian species were the phytogeographical types most found in these areas.The microphanerophytes were the most represented life form.The structural parameters such as diameter and height means,the basal area and the densities determined and submitted to post-hoc test show some important similarity between some groups found.In overall,the vegetation condition of the three protected areas is somehow disturbed while most of the plant communities are stable.These preliminary ecological data obtained are essential and fundamental for the management and protection for these ecosystems.

Roof Shale Flora of Coal Seam 6 from the Asselian(Lower Permian) Taiyuan Formation of the Wuda Coalfield,Inner Mongolia and Its Ecostratigraphic Significance

Roof shale floras help understand the transition of vegetational landscapes from a peat–forming environment to a clastic one, but are seldom investigated in the Cathaysian province（typical present day China and East Asia）. Here the roof shale flora of Coal Seam 6 from the lower Permian Taiyuan Formation of the Wuda Coalfield, Inner Mongolia, is systematically described and its ecostratigraphic and phytogeographic implications are discussed. The flora is composed of seven plant groups, including Lepidodendrales, Medullosales, Gigantopteridales, Peltaspermales, Noeggerathiales, Cordaitales and Cycadales. Many of these taxa are also documented in Euramerica, and the floral composition indicates a more intimate relationship between Cathaysia and Euramerica during the Cisuralian than previously thought. However, there are few genera and species in common with those of the underlying peat–forming flora. Moreover, the flora is hardly comparable with the commonly known flora of the Taiyuan Formation. Such assemblage differences are very likely due to changes of taphonomic and environmental phases, rather than evolutionary floral succession. For a full and more precise understanding of the floral composition, succession and the floristic discrepancy in different depositional environments, an ecostratigraphic investigation on the Late Palaeozoic of Cathaysia is advocated.

Modulations in seed micromorphology reveal signature of adaptive species-diversification in <i>Dendrobium</i>(Orchidaceae)

During speciation in flowering plants, many morphological characters were evolved in response to continuous selection pressure. Such characters are largely governed by genetic changes or get modulated according to ecological adaptations. To explore the potential of latter, a novel comparative analysis of seed micromorphology and ultrastructure was performed in twenty species in the genus Dendrobium (Orchidaceae) from well-defined altitude based phytogeographical realms i.e. temperate, subtropical and tropical regions. Seed morphological characteristics from all collected species were examined using 13 quantitative traits descriptors. Comparative seed morphology revealed that the species from temperate region have larger seed volumes and seed volume/embryo volume ratio than species from subtropical or tropical regions irrespective of their phylogenetic association. Hence, phylogenetically related species emphasized their preference for a climatic region as their prime habitat. Similar trends towards gradual increase of percentage free air space were observed in the species of tropical to subtropical and subtropical to temperate regions. The higher percentage of free air space may have an advantage for the species from temperate region with relatively low atmospheric pressure that had greater buoyancy for optimal seed dispersal. Also, phylogenetically distant species from a particular climatic region, showed characteristic features of the testa cell walls sculptured with bead-like orna-mentations or covered with cottony white substances. Based on these observations, it may be concluded that seed volume, % free air space and seed coat ornamentation in Dendrobium species are signatures of adaptation according to climatic preferences rather than their selection during speciation.

Jurassic Flora in Southern Mexico: <i>Anomozamites</i>Schimper, 1870 Emend. Pott et McLoughlin, 2009 from Mixteco Terrane, Phytogeographical Implications of Williamsoniaceae Family (Bennettitales)

Anomozamites is a fossil-genus of leaf attributed to the Bennettitales, with a distribution mainly in the Kingdom of Laurasia and a stratigraphic range of the Upper Triassic to the Lower Cretaceous. In Mexico there were only reports of some specimens until the 1980s and later of four fossil-species at the beginning of the 21st century, all of them from the Jurassic in the Mixteco Terrane. In this review, three fossil-species of Anomozamites are identified: A. angustifolium is the first of them, which is a fossil-taxon with a range of the Rhaetian to Bajocian and Euramerican distribution;the second one is A. cf. triangularis, of which the geographic and stratigraphic extension of fossil-taxon is proposed;finally, we propose the existence of the A. sp.1, informally named, but with morphological characters that do not match the descriptions of Triassic/Jurassic fossil-taxa. These identifications were made based on macromorphology of the foliar organs and on the review of the diagnostic characters of both the fossil-genus and the fossil-species of taxonomic validity. Then, with this study, the taxonomic and phytogeographic knowledge of Anomozamites during the Jurassic period is increased and this allows reconsidering the amplitude of the Wielandiella distribution, a fossil-genus related to Anomozamites due to the existence of two fossil-taxa in organic connection.

The first megafossil of Cibotium within its modern distribution

The‘man fern’(Cibotium,Cibotiaceae),a typical tree fern of tropical and subtropical climates,is today mainly distributed in the Hawaiian Islands,Mesoamerica,and tropical and subtropical regions of East and Southeast Asia.Reliable fossil records of this genus are rare.Only two cases of stem fossils have been reported from the Upper Cretaceous of Iwate-Ken,Japan and the upper Eocene of Oregon,USA.In this paper,ultimate fertile pinna fossils of Cibotium are described from the Miocene Erzitang Formation of Guiping Basin,Guangxi Zhuang Autonomous Region,South China,which also preserve in situ spores and cuticles.As the first global discovery of Cibotium pinna fossils preserving both in situ spores and cuticles,this find enriches the organ types of Cibotium fossils.This is also the first discovery of Cibotium fossils within its modern distribution range,indicating that Cibotium had migrated southwards into its modern distribution by at least the Miocene.Based on the modern habitat of Cibotium,we infer that the Guiping Basin was under a warm and humid tropical/subtropical climate in the Miocene.

Cenozoic flora of western India and its significance in palaeoclimatic and palaeophytogeographic interpretation

The Cenozoic flora of western India(Rajasthan and Gujarat) is adversely affected by the tectonic activity such as collision of the Indian subcontinent with the Eurasian plate which is responsible for the Himalayan and Tibetan Plateau uplift. This collision and its resultants affected the ubiquitous tropical lowland vegetation of the Indian subcontinent(including western India) and are responsible for different types of topographic regions as seen today in the Indian subcontinent. The region is important as it has witnessed a drastic change in climate of the region since the Cenozoic time and also provided opportunities to the western and eastern flora to intermingle. The main basins in western India comprising Cenozoic sequences are: Bikaner-Nagaur, Jaisalmer and Barmer in Rajasthan and Kachchh, Mainland and Saurashtra in Gujarat. These basins are very rich in lignite which is the main source of electric power generation in western India. This lignite is mainly of Eocene in age. The Cenozoic flora of western India was almost tropical growing in well drained areas as compared to arid to sub-humid regions with xeric vegetation today. The reported fossils are represented by leaves, woods, fruits and seeds. The leaves are abundant in the Palaeogene as compared to the Neogene. The Neogene period can be marked by the abundant legumes and dipterocarpaceous remains. The important families viz., Anacardiaceae, Annonaceae, Arecaceae, Calophyllaceae, Clusiaceae, Combretaceae, Euphorbiaceae, Flacourtiaceae, Icacinaceae, Lauraceae, Lythraceae, Meliaceae, Moraceae, Myrtaceae, Pandanaceae and Sonneratiaceae have been reported from the Palaeogene sediments, whereas Anacardiaceae, Araucariaceae, Arecaceae, Combretaceae, Dipterocarpaceae, Fabaceae, Lauraceae, Lecythidaceae, Lythraceae, Malvaceae, Meliaceae, Moraceae, Podocarpaceae, Rhamnaceae, Rhizophoraceae, Rutaceae, Sapindaceae and Sonneratiaceae are known from the Neogene sediments. All the recovered elements strongly indicate the presence of much better climatic conditions in the region during the Cenozoic as compared to the present. More importantly, a fossil fruit of Cocos L. described from the Eocene sediments of Rajasthan further indicates the presence of sea in the nearby area at the time of deposition of the sediments. The recovery of a few African elements from western India provides the evidence of establishment of land connections between India and Africa up to the Plio-Pleistocene through which these elements could enter the Indian subcontinent.