Upper Cretaceous sulcate pollen from the Timerdyakh Formation,Vilui Basin (Siberia)

One inaperturate and 16 monosulcate pollen types are described from the latest Campanian to earliest Maastrichtian sediments of the Vilui basin, Siberia, using both light and scanning electron microscopy, and assigned systematically when possible to modern families or subfamilies. Despite their scant occurrence, the pollen grains show considerable diversity. Two new genera have been erected. Lasioideaecidites with two species, Lasioideaecidites hessei and Lasioideaecidites bogneri, represents the earliest record of the subfamily Lasioideae (Araceae). Aristolochiacidites with one species, Aristolochiacidites viluiensis, is assigned to the subfamily Aristolochioideae (Aristolochiaceae) and represents the first fossil pollen record of the family. A new species of Liliacidites, Liliacidites goldblattii, is closely similar to pollen of Isophysioideae (Iridaceae) and/or Doryanthaceae and is the first fossil evidence of the clade that includes these closely related families. A further nine new fossil species are described (Clavatipollenites timerdyakhensis, Liliacidites palaeofritillaria, Retimonocolpites longosucatus, R. microreticulatus, R. microrugulatus, R. lysichitonoides, R. chapmaniae, Monosulcites parvus and Arecipites tyungensis) and assigned to Chloranthaceae, Araceae (Orontioideae, ?Pothoideae), Liliaceae, ?Hypoxidaceae and Arecaceae. The Hydatellaceae (Nymphaeales) may also be present in the palynoflora of the Vilui Basin, represented by pollen similar to M. rivularis Braman from the Santonian to Campanian (Upper Cretaceous) Milk River Formation, Canada.     

New insights into the phylogeny and biogeography of subfamily Orontioideae (Araceae)

Proto‐Araceae, the earliest diverged lineage within the family Araceae, includes two subfamilies, Gymnostachydoideae (one species) and Orontioideae (eight species). Based on an extensive sampling (a total of 198 accessions) of six chloroplast non‐coding regions (5799 aligned sites), we assessed phylogenetic relationships among the genera and species within subfamily Orontioideae and estimated the timing of intercontinental disjunct events in the Northern Hemisphere. Overall phylogenetic relationships among the genera were consistent with results from previous studies, but several new important findings were discovered, primarily within Symplocarpus Salisb. ex W. P. C. Barton. First, two major lineages within Symplocarpus were identified: one lineage included S. foetidus (L.) Salisb. ex W. Barton, S. nabekuraensis Otsuka & K. Inoue, and S. renifolius Schott ex Tzvelev (Japan), whereas the other included S. nipponicus Makino, S. egorovii N. S. Pavlova & V. A. Nechaev, and S. renifolius (Korea). Symplocarpus renifolius in Japan was tetraploid and closely related to the tetraploid S. foetidus in eastern North America. Populations of S. renifolius in Korea were confirmed to be diploid (2n = 30) and shared the most recent common ancestor with the other diploid species, S. nipponicus. Second, two recently described species, S. nabekuraensis and S. egorovii, were deeply embedded within S. renifolius in Japan and Korea, respectively, and their distinct taxonomic status requires further assessment. Finally, two intercontinental disjunction events in the subfamily, one in Lysichiton Schott between eastern Asia and western North America and the other in Symplocarpus between eastern Asia and eastern North America, were estimated to be between 4.5 and 1.4 million years ago (Pliocene and Pleistocene) and between 1.9 and 0.5 million years ago (Pleistocene), respectively.