The "evil tribe" spreads across the land: A dated molecular phylogeny provides insight into dispersal, expansion, and biogeographic relationships within one of the largest tribes of the sunflower family (Vernonieae: Compositae).

PREMISE: With over 1500 species, the globally distributed Vernonieae is one of the most successful members of the largest family of flowering plants, the Compositae. However, due to its morphological complexity and limited geographic representation in previous studies, subtribal and biogeographic relationships are unclear. Here, new DNA sequence data spanning the geographic range of the tribe provides a taxonomically robust time-calibrated phylogeny, estimates migration pathways and timing of important biogeographic events, and allows inference of environmental factors that have contributed to the success of the Vernonieae worldwide. METHODS: Phylogenetic relationships were estimated for 368 taxa representing all Vernonieae subtribes. Molecular clock and ancestral range estimation analyses provide a framework for inference of the biogeographic history of the tribe. RESULTS: Relationships among the subtribes were established and correct placement determined for problematic taxa, along with the first model-based assessment of the biogeographic history of the tribe. The Vernonieae were estimated to have evolved ~50 mya. Africa was the first center of diversity, from which a single dispersal event established the monophyletic New World lineage. Long-distance dispersal from Africa and Brazil established the tribe on five continents and Oceania. CONCLUSIONS: The New World lineage is monophyletic, but Old World taxa are not. New subtribal taxonomies are needed. Moquinieae are nested in Vernonieae. Long-distance dispersal from Africa beginning 45 mya was key to establishing the tribe's near-global distribution. Migration corridors created by volcanic mountain chains and iron-rich soils in Africa and the Americas promoted radiation and range expansion.

A long distance dispersal hypothesis for the Pandanaceae and the origins of the Pandanus tectorius complex.

Pandanaceae (screwpines) is a monocot family composed of c. 750 species widely distributed in the Paleotropics. It has been proposed that the family may have a Gondwanan origin with an extant Paleotropical distribution resulting from the breakup of that supercontinent. However, fossils supporting that hypothesis have been recently reassigned to other families while new fossil discoveries suggest an alternate hypothesis. In the present study, nuclear and chloroplast sequences were used to resolve relationships among Pandanaceae genera. Two well-supported fossils were used to produce a chronogram to infer whether the age of major intra-familial lineages corresponds with the breakup of Gondwana. The Pandanaceae has a Late Cretaceous origin, and genera on former Gondwanan landmasses began to diverge in the Late Eocene, well after many of the southern hemisphere continents became isolated. The results suggest an extant distribution influenced by long-distance-dispersal. The most widespread group within the family, the Pandanus tectorius species complex, originated in Eastern Queensland within the past six million years and has spread to encompass nearly the entire geographic extent of the family from Africa through Polynesia. The spread of that group is likely due to dispersal via hydrochory as well as a combination of traits such as agamospermy, anemophily, and multi-seeded propagules which can facilitate the establishment of new populations in remote locations.

Molecular phylogeny and dating of Asteliaceae (Asparagales): Astelia s.l. evolution provides insight into the Oligocene history of New Zealand.

Asteliaceae (4 genera, 36 species) are found on both continents and island archipelagos in the southern hemisphere and across the Pacific. The circumscription of Asteliaceae and intrageneric relationships are poorly understood. We generated a phylogeny including all genera and 99% of the species using DNA sequence data from chloroplast (trnL, psbA-trnH, rps16, and petL-psbE) and nuclear (NIA-i3) regions. Relaxed clock methods were applied to infer the age of the family and the timing of cladogenic events. Generic delimitations change as a result of this study. Collospermum is nested within Astelia and is recognized here only at the subgeneric level. Further, Astelia subgenera Astelia, Asteliopsis, and Tricella are paraphyletic and to achieve monophyly their recircumscriptions are proposed. Despite the presence of Asteliaceae taxa on multiple Gondwanan landmasses and proposed Cretaceous origins for the family, radiation of genera was during the Tertiary. The largest and oldest genus, Astelia s.l. (including Collospermum), radiated around the Eocene/Oligocene boundary (ca. 34.2 million years ago (Ma)). Astelia s.l. subgenera diverged from the Oligocene/Miocene boundary onwards (<24.0 Ma). These dates suggest that current distributions are most likely to be the result of long-distance dispersal. Alpine taxa in New Zealand and Australia radiated during the Late Miocene/Pliocene. These results are congruent with Astelia micro- and macro-fossil data and suggest that Astelia s.l. either persisted in New Zealand during the proposed Oligocene marine transgression or dispersed from Australia after the subsequent expansion of terrestrial habitat.

Biogeography and evolutionary diversification in one of the most widely distributed and species rich genera of the Pacific.

The historical biogeography of many lineages-of both terrestrial and marine ocean habitats-remains poorly investigated even though remote ocean habitat covers approximately 66% of the Earth's surface. One such lineage with poorly understood biogeographic affinities across vast ocean habitat is the genus Coprosma (Rubiaceae) with numerous species, and a widespread and disjunct distribution among the far-flung insular localities of multiple Pacific Islands. Here, the first taxonomically robust phylogeny for Coprosma s.s. was dated using molecular clock techniques and indicated Coprosma s.s. diverged from its sister genus Nertera likely during or shortly after the Oligocene Marine Transgression of New Zealand. Diversification of the five major clades identified occurred in New Zealand during the Miocene, which was then followed by multiple independent dispersals from New Zealand to various localities in many directions. The pattern of Coprosma's distribution in the Pacific appears stochastic both temporally and spatially, but evolution of an orange to red fruit colour prior to nearly all inferred dispersals hints at endozoochory by birds. The number of inferred long-distance dispersals of Coprosma s.s. (>30), and number of repeated dispersals to the same insular locality from unrelated Coprosma s.s. sublineages (>8) is perhaps the most currently known for a remote Pacific-centred genus investigated to date. A New Zealand origin for a Pacific-wide dispersal of taxa is not novel, but the manner in which the temporal and spatial distribution for Coprosma s.s. was achieved contributes to a novel understanding of the historical biogeography of widespread Pacific genera that have origins in the Southern Hemisphere.

A refined concept of the Critoniopsisbogotana species group in Colombia with two new species (Vernonieae, Asteraceae).

Critoniopsisbogotana is more precisely delimited, and two related Colombian species are described as new. The form of trichomes on the abaxial surfaces of the leaves is found to be of major importance. A short key to the Critoniopsisbogotana group is provided.

Revisions and key to the Vernonieae (Compositae) of Thailand.

Seventeen genera and 48 species, in five subtribes, are recognized in Thailand. These include 15 endemic taxa, half of which are in the largest genus, Acilepis, with others in the genera Camchaya, Koyamasia, and Okia. A new monotypic genus, Pulicarioidea, is established with P. annamica, the new name for the species formerly known as Vernonia pulicarioides. New combinations are also made for Acilepis kerrii, Cyanthillium montanum, Koyamasia curtisii and Okia pseudobirmanica. Forty-six characters including habit, leaf, flower, achene and pollen morphology were analyzed using UPGMA. Five clusters of taxa were identified. Keys to genera, species and varieties, descriptions, vernacular names, ecological data and illustrations are provided.

Two new genera, Hoffmannanthus and Jeffreycia, mostly from East Africa (Erlangeinae, Vernonieae, Asteraceae).

Two genera of Vernonieae subtribe Erlangeinae with Type A pollen, 5-ribbed achenes, and blunt-tipped sweeping hairs on the styles are described as new, Hoffmannanthus with one species and with Vernonia brachycalyx O. Hoffm. as type, and Jeffreycia with five known species, with Vernonia zanzibarensis Less. as type. Vernonia abbotiana O. Hoffm. is neotypified and is an older name for V. brachycalyx.

A new species of Camchaya (Asteraceae, Vernonieae) from Thailand.

Camchaya thailandica Bunwong, Chantar. & S.C.Keeley, sp. nov. from Phu Phrabat Historical Park, Udon Thani, Thailandis described as a new species. Plant of this new species are similar to Camchaya gracilis (Gagnep.) Bunwong & H.Rob. but differ in having ovate phyllaries without margin spines, 10-ribbed achenes, and broadly ovate leaves. This species is a rare endemic known only from the type collection and probably confined to open areas of sandstone hills in Udon Thani province.

A phylogeny of the "evil tribe" (Vernonieae: Compositae) reveals Old/New World long distance dispersal: support from separate and combined congruent datasets (trnL-F, ndhF, ITS).

The Vernonieae is one of the major tribes of the largest family of flowering plants, the sunflower family (Compositae or Asteraceae), with ca. 25,000 species. While the family's basal members (the Barnadesioideae) are found in South America, the tribe Vernonieae originated in the area of southern Africa/Madagascar. Its sister tribe, the Liabeae, is New World, however. This is the only such New/Old World sister tribe pairing anywhere in the family. The Vernonieae is now found on islands and continents worldwide and includes more than 1500 taxa. The Vernonieae has been called the "evil tribe" because overlapping character states make taxonomic delimitations difficult at all levels from the species to the subtribe for the majority of taxa. Juxtaposed with these difficult-to-separate entities are monotypic genera with highly distinctive morphologies and no obvious affinities to any other members of the tribe. The taxonomic frustration generated by these contrary circumstances has resulted in a lack of any phylogeny for the tribe until now. A combined approach using DNA sequence data from two chloroplast regions, the ndhF gene and the noncoding spacer trnL-F, and from the nuclear rDNA ITS region for 90 taxa from throughout the world was used to reconstruct the evolutionary history of the tribe. The data were analyzed separately and in combination using maximum parsimony (MP), minimum evolution neighbor-joining (NJ), and Bayesian analysis, the latter producing the best resolved and most strongly supported tree. In general, the phylogeny shows Old World taxa to be basal and New World taxa to be derived, but this is not always the case. Old and New World species are found together in two separate and only distantly related clades. This is best explained by long-distance dispersal with a minimum of two trans-oceanic exchanges. Meso/Central America has had an important role in ancient dispersals between the Old and New World and more recent movements from South to North America in the New World.