Glochidionyangchunense (Phyllanthaceae), a new species with discoid flowers from Guangdong Province, China.

Phyllanthodendron can be readily morphologically distinguished from Glochidion, but recent molecular evidence showed that Phyllanthodendron is paraphyletic due to Glochidion being nested within it. In this study, a new species of the former Phyllanthodendron is described and illustrated as Glochidionyangchunense Z.Q. Song & Gang Yao from the limestone areas of South China. This is a peculiar new species and morphologically distinguished by its discoid flowers, T-shaped disc segments, and glabrous flowering branches. A key to Glochidionyangchunense and related species in China is provided here.

Taxonomic notes on the genus Itea (Iteaceae).

The genus Itea (Iteaceae) is recognised as a genus with about 21 extant species of shrubs and trees. Within the genus, most species have oblong to elliptical leaves. The lanceolate and obolanceolate leaves are only found in three species, vix Iteaamoena Chun, Iteariparia Collett & Hemsl. and Iteatenuinervia S. Y. Liu. The results of our examination of literature, specimens and living plants in the wild have shown that Iteatenuinervia is conspecific with Iteariparia and is here reduced to a synonym of the latter species. The morphological description, colour pictures, voucher specimens, distribution map of Iteariparia and its related Iteaamoena, together with the morphological comparisons between the two species, are provided in this study.

'Out of Africa' origin of the pantropical staghorn fern genus Platycerium (Polypodiaceae) supported by plastid phylogenomics and biogeographical analysis.

BACKGROUND AND AIMS: The staghorn fern genus Platycerium is one of the most commonly grown ornamental ferns, and it evolved to occupy a typical pantropical intercontinental disjunction. However, species-level relationships in the genus have not been well resolved, and the spatiotemporal evolutionary history of the genus also needs to be explored. METHODS: Plastomes of all the 18 Platycerium species were newly sequenced. Using plastome data, we reconstructed the phylogenetic relationships among Polypodiaceae members with a focus on Platycerium species, and further conducted molecular dating and biogeographical analyses of the genus. KEY RESULTS: The present analyses yielded a robustly supported phylogenetic hypothesis of Platycerium. Molecular dating results showed that Platycerium split from its sister genus Hovenkampia ~35.2 million years ago (Ma) near the Eocene-Oligocene boundary and began to diverge ~26.3 Ma during the late Oligocene, while multiple speciation events within Platycerium occurred during the middle to late Miocene. Biogeographical analysis suggested that Platycerium originated in tropical Africa and then dispersed eastward to southeast Asia-Australasia and westward to neotropical areas. CONCLUSIONS: Our analyses using a plastid phylogenomic approach improved our understanding of the species-level relationships within Platycerium. The global climate changes of both the Late Oligocene Warming and the cooling following the mid-Miocene Climate Optimum may have promoted the speciation of Platycerium, and transoceanic long-distance dispersal is the most plausible explanation for the pantropical distribution of the genus today. Our study investigating the biogeographical history of Platycerium provides a case study not only for the formation of the pantropical intercontinental disjunction of this fern genus but also the 'out of Africa' origin of plant lineages.

Geographical patterns and determinants in plant reproductive phenology duration.

Biodiversity is and always has been an important issue in ecological research. Biodiversity can reflect niche partitioning among species at several spatial and temporal scales and is generally highest in the tropics. One theory to explain it is that low-latitude tropical ecosystems are dominated by species that are generally only distributed over a narrow area. This principle is known as Rapoport's rule. One previously unconsidered extension of Rapoport's rule may be reproductive phenology, where variation in flowering and fruiting length may reflect a temporal range. Herein, we collected reproductive phenology data for more than 20,000 species covering almost all angiosperm species in China. We used a random forest model to quantify the relative role of seven environmental factors on the duration of reproductive phenology. Our results showed that the duration of reproductive phenology decreased with latitude, although there was no obvious change across longitudes. Latitude explained more of the variation in the duration of flowering and fruiting phases in woody plants than in herbaceous plants. Mean annual temperature and the length of the growing season strongly influenced the phenology of herbaceous plants, and average winter temperature and temperature seasonality were important drivers of woody plant phenology. Our result suggests the flowering period of woody plants is sensitive to temperature seasonality, while it does not influence herbaceous plants. By extending Rapoport's rule to consider the distribution of species in time as well as space, we have provided a novel insight into the mechanisms of maintaining high levels of diversity in low-latitude forests.

Phylogenetic analysis and temporal diversification of the tribe Alsineae (Caryophyllaceae) with the description of three new genera, Hesperostellaria, Reniostellaria and Torreyostellaria.

Alsineae are one of the most taxonomically difficult tribes in Caryophyllaceae and consist of over 500 species distributed in the northern temperate zone. Recent phylogenetic results have improved our understanding on the evolutionary relationships among Alsineae members. Nevertheless, there are still some unresolved taxonomic and phylogenetic problems at the generic level, and the evolutionary history of major clades within the tribe was unexplored to date. In this study, we carried out phylogenetic analyses and divergence time estimation of Alsineae using the nuclear ribosomal internal transcribed spacer (nrITS) and four plastid regions (matK, rbcL, rps16, trnL-F). The present analyses yielded a robustly supported phylogenetic hypothesis of the tribe. Our results showed that the monophyletic Alsineae are strongly supported to be the sister of Arenarieae, and the inter-generic relationships within Alsineae were mostly resolved with strong support. Both molecular phylogenetic and morphological evidence supported the Asian species Stellaria bistylata and the two North American species Pseudostellaria jamesiana and Stellaria americana all should be recognized as new monotypic genera respectively, and three new genera Reniostellaria, Torreyostellaria, and Hesperostellaria were thereby proposed here. Additionally, molecular and morphological evidence also supported the proposal of the new combination Schizotechium delavayi. Nineteen genera were accepted within Alsineae and a key to these genera was provided. Molecular dating analysis suggested that Alsineae splitted from its sister tribe at ca. 50.2 million-years ago (Ma) during the early Eocene and began to diverge at ca. 37.9 Ma during the late Eocene, and divergent events within Alsineae occurred mainly since the late Oligocene. Results from the present study provide insights into the historical assembly of herbaceous flora in northern temperate regions.

Taxonomic revision of the genus Glochidion (Phyllanthaceae) in Taiwan, China.

A comprehensive taxonomic revision of the genus Glochidion J.R. Forst. & G. Forst. from Taiwan in China was carried out based on the examination of herbarium specimens and filed investigations. Eight species and three varieties are recognized, including a new species endemic to Taiwan, G. lanyuense Gang Yao & S.X. Luo, which is described and illustrated. Three names, viz. G. chademenosocarpum Hayata, G. kusukusense Hayata, and G. ovalifolium F.Y. Lu & Y.S. Hsu, are reduced to the new synonyms of G. rubrum Blume, G. lanceolatum Hayata, and G. ellipticum Wight, respectively. Two names, viz. G. lanceolatum Hayata and G. suishaense Hayata, are lectotypified here. A key to the Glochidion species in Taiwan is provided.

Return Verdesmummenglaense to the genus Hylodesmum (Fabaceae) based on morphological and molecular evidence.

Verdesmummenglaense (C. Chen & X. J. Cui) H. Ohashi & K. Ohashi is a rare species in the tribe Desmodieae (Fabaceae) from Southwest China. The morphological observation shows that the species has minute capitate stigma and ebracteolate calyces, which are entirely different from the funnel-shaped stigma and bracteolate calyces of the genus Verdesmum H. Ohashi & K. Ohashi, but are consistent with those of the genus Hylodesmum H. Ohashi & R. R. Mill. The generic placement of V.menglaense within Hylodesmum was further supported by molecular evidence. Therefore, this species should be returned to Hylodesmum as H.menglaense (C. Chen & X. J. Cui) H. Ohashi & R. R. Mill. A full description including floral characters, a colour plate and a distribution map are first provided here for this species. After excluding the solo representative in China, Verdesmum should be removed from the record in Flora of China.

Taxonomic studies of Glochidion (Phyllanthaceae) from the Indo-China Peninsula (II): The identities of G.anamiticum and G.annamense.

The names Glochidionanamiticum (Kuntze) Kuntze ex Merrill and G.annamense Beille were previously reduced to synonyms of G.eriocarpum Champ. ex Benth. However, literature examination and morphological comparison suggest that G.annamense is conspecific with G.anamiticum and the species can be readily distinguished from G.eriocarpum by its styles connate into a long cylindric column and up to 3 mm long, ovaries usually 3-locular, stigma usually 3-lobed, capsules pubescent and usually 6-grooved, persistent styles 3‒4 mm long. Thus, the specific status of G.anamiticum is here reinstated and G. annamense is treated as its synonym.

Leaves and fruits of Bauhinia (Leguminosae, Caesalpinioideae, Cercideae) from the Oligocene Ningming Formation of Guangxi, South China and their biogeographic implications.

BACKGROUND: The pantropical genus Bauhinia, along with the northern temperate Cercis and several tropical genera, bear bilobate, bifoliolate, or sometimes unifoliolate leaves, which constitute the tribe Cercideae as sister to the rest of the family Leguminosae based on molecular phylogenetics. Hence, the fossil record of Cercideae is pivotal to understand the early evolution and biogeographic history of legumes. RESULTS: Three fossil species of Bauhinia were described from the Oligocene Ningming Formation of Guangxi, South China. Bauhinia ningmingensis sp. nov. is characterized by its bifoliolate, pulvinate leaves bearing basal acrodromous primary veins and brochidodromous secondary veins. B. cheniae sp. nov. bears moderately or deeply bilobate, pulvinate leaves, with basal actinodromous primary veins and eucamptodromous secondary veins. B. larsenii D.X. Zhang et Y.F. Chen emend. possesses shallowly or moderately bilobate, pulvinate leaves bearing basal actinodromous primary veins and brochidodromous secondary veins, as well as elliptic, stipitate, non-winged, and oligo-seeded fruits. Meanwhile, previously reported Bauhinia fossils were reviewed, and those pre-Oligocene foliage across the world are either questionable or have been rejected due to lacking of reliable evidence for their pulvini or/and basal actinodromous or acrodromous venations. Besides Oligocene leaves and fruits presented here, foliage and/or wood of Bauhinia have been documented from the Miocene-Pliocene of Thailand, India, Nepal, Uganda, and Ecuador. CONCLUSIONS: Bauhinia has exhibited a certain diversity with bifoliolate- and bilobate-leafed species in a low-latitude locality-Ningming since at least the Oligocene, implying that the tropical zone of South China may represent one of the centres for early diversification of the genus. The reliable macrofossils of Bauhinia and Cercis have made their debut in the Eocene-Oligocene floras from mid-low latitudes and appeared to lack in the coeval floras at high latitudes, implying a possible Tethys Seaway origin and spread of legumes. However, detailed scenarios for the historical biogeography of Bauhinia and its relatives still need more robust dataset from palaeobotany and molecular phylogeny in future research.