The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold‐temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing on the biogeography of particular groups during the last few decades, a global analysis of Carex biogeography and diversification is still lacking. For this purpose, we built the hitherto most comprehensive Carex‐dated phylogeny based on three markers (ETS–ITS–matK), using a previous phylogenomic Hyb‐Seq framework, and a sampling of two‐thirds of its species and all recognized sections. Ancestral area reconstruction, biogeographic stochastic mapping, and diversification rate analyses were conducted to elucidate macroevolutionary biogeographic and diversification patterns. Our results reveal that Carex originated in the late Eocene in E Asia, where it probably remained until the synchronous diversification of its main subgeneric lineages during the late Oligocene. E Asia is supported as the cradle of Carex diversification, as well as a “museum” of extant species diversity. Subsequent “out‐of‐Asia” colonization patterns feature multiple asymmetric dispersals clustered toward present times among the Northern Hemisphere regions, with major regions acting both as source and sink (especially Asia and North America), as well as several independent colonization events of the Southern Hemisphere. We detected 13 notable diversification rate shifts during the last 10 My, including remarkable radiations in North America and New Zealand, which occurred concurrently with the late Neogene global cooling, which suggests that diversification involved the colonization of new areas and expansion into novel areas of niche space.
Phylogenetic studies of Carex L. (Cyperaceae) have consistently demonstrated that most subgenera and sections are para-or polyphyletic. Yet, taxonomists continue to use subgenera and sections in Carex classification. Why? The Global Carex Group (GCG) here takes the position that the historical and continued use of subgenera and sections serves to (i) organize our understanding of lineages in Carex, (ii) create an identification mechanism to break the~2000 species of Carex into manageable groups and stimulate its study, and (iii) provide a
Background Southeast Asia, together with tropical Africa, Madagascar, South India and Sri Lanka, and the eastern Himalayas, are the five primary hotspots of species diversity of Impatiens (Balsaminaceae). China is also rich in Impatiens species, especially in the limestone karsts or ‘Danxia’ landforms. With zygomorphic flowers and diverse corolla morphology and color, the species in Impatiens are well-known for their ornamental use, but they are also notorious in taxonomy. During the preparation of revision of Impatiens in Zhejiang and adjacent regions, an unknown species was collected from Mt. Wuyi in Fujian Province, Southeast China. Results Phylogenetic analyses based on nuclear ITS, chloroplast atpB-rbcL and trnL-F sequences, together with micromorphology of pollen grains and seed coats, strongly supported the close relationship of the new species with Impatiens platysepala Y.L.Chen and I. chloroxantha Y.L.Chen. In turn, both molecular data and morphological characters also were sufficient to distinguish the new species from the other two counterparts. Conclusions Our detailed morphological observations and molecular phylogenetic analyses support the recognition of Impatiens wuyiensis as a species new to science.
Celtis neglecta Zi L. Chen & X. F. Jin, a new species from Zhejiang, China, is described and illustrated. This new species is most similar to Celtis julianae C. K. Schneid. and C. vandervoetiana C. K. Schneid. It differs from Celtis julianae in having young shoots, petioles, and both mid-ribs and lateral veins of the lower leaf surfaces densely whitish pubescent, and fruit pedicels glabrous or sparsely whitish pubescent. It differs from Celtis vandervoetiana in having young shoots and petioles densely whitish pubescent, and being sparsely whitish pubescent on the upper leaf surfaces, and densely whitish pubescent on both mid-ribs and lateral veins of the lower leaf surfaces. Sequences of the plastid intergenic spacer regions atpB-rbcL and trnL-trnF demonstrate that Celtis julianae and C. vandervoetiana are the closest extant relatives of this new species.
Recent fieldwork in the Chinese province of Zhejiang revealed new insights into the taxonomy of the genus Carex in this area. Carex honglinii, a new species of Carex sect. Confertiflorae, is described. It differs from C. pseudodispalata in having perigynia broadly obovoid, contracted into a ca. 0.5‒0.7 mm long beak at the apex, and staminate scales acuminate. Carex nemostachys var. subglabra (sect. Confertiflorae) is raised to specific rank and combined as C. subglabra. Eventually, a new subspecies of Carex scopulus (subsp. aristata; sect. Mitratae) is described. This new subspecies differs from the type subspecies in having pistillate scales with a 1‒4 mm long apical scabrous awn, and leaves 1.5‒2.5 wide.
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