Aim

The biogeography of the grass genera Festuca (subgenus Schedonorus) and Lolium, which form one of the world main forage groups, is here reconstructed for the first time using nuclear and plastid

data. We aimed to test previous hypotheses on the origin of the group ancestor and on the Holocene versus pre‐Holocene dispersals of the most recent fodder grasses.

Location

The Mediterranean Basin and neighbouring regions: North Africa, Southwest Asia, East and West Africa, and Eurasia.

Methods

Sampling included nearly all representatives from the native Old World distribution of this group. We used maximum parsimony, maximum likelihood and Bayesian inference methods to reconstruct phylogenetic relationships. Divergence times were estimated with a Bayesian relaxed clock and secondary calibrations derived from a fossil‐dated phylogeny of grasses. Biogeographical scenarios were reconstructed with Bayesian‐averaged dispersal–vicariance analysis (Bayes‐

DIVA

) and dispersal–extinction–cladogenesis (

DEC

), using a stratified palaeogeographical model spanning the last 12 million years.

Results

Meadow fescue (Festuca pratensis) originated in Eurosiberia, Southwest Asia, 2 million years ago (Ma), whereas ryegrasses (Lolium) first diversified in the eastern Mediterranean region around 4.1 Ma, splitting into two autogamous versus allogamous lineages, with Macaronesian Lolium embedded within the latter. An alternative scenario suggests, however, an early split of the Macaronesian ryegrasses. Our results support the hybrid origin of the tall fescue (Festuca arundinacea).

Main conclusions

The ancestor of the fescues and ryegrasses originated in the western Mediterranean in the mid‐Miocene. The sister relationship of the tropical African Festuca simensis to Lolium is a novel finding, suggesting a dispersal of the ancestor of the ryegrasses from Asia to East Africa in the early Pliocene. Our reconstruction rejects the hypothesis of a single Neolithic human‐mediated dispersal of Lolium species from eastern to western Mediterranean areas, suggesting instead a pre‐agricultural distribution of Lolium ancestors along the Mediterranean Basin since the Pliocene.

Aim Recently developed parametric methods in historical biogeography allow researchers to integrate temporal and palaeogeographical information into the reconstruction of biogeographical scenarios, thus overcoming a known bias of parsimony-based approaches. Here, we compare a parametric method, dispersal–extinction–cladogenesis (DEC), against a parsimony-based method, dispersal–vicariance analysis (DIVA), which does not incorporate branch lengths but accounts for phylogenetic uncertainty through a Bayesian empirical approach (Bayes-DIVA). We analyse the benefits and limitations of each method using the cosmopolitan plant family Sapindaceae as a case study. Location World-wide. Methods Phylogenetic relationships were estimated by Bayesian inference on a large dataset representing generic diversity within Sapindaceae. Lineage divergence times were estimated by penalized likelihood over a sample of trees from the posterior distribution of the phylogeny to account for dating uncertainty in biogeographical reconstructions. We compared biogeographical scenarios between Bayes-DIVA and two different DEC models: one with no geological constraints and another that employed a stratified palaeogeographical model in which dispersal rates were scaled according to area connectivity across four time slices, reflecting the changing continental configuration over the last 110 million years. Results Despite differences in the underlying biogeographical model, Bayes-DIVA and DEC inferred similar biogeographical scenarios. The main differences were: (1) in the timing of dispersal events – which in Bayes-DIVA sometimes conflicts with palaeogeographical information, and (2) in the lower frequency of terminal dispersal events inferred by DEC. Uncertainty in divergence time estimations influenced both the inference of ancestral ranges and the decisiveness with which an area can be assigned to a node. Main conclusions By considering lineage divergence times, the DEC method gives more accurate reconstructions that are in agreement with palaeogeographical evidence. In contrast, Bayes-DIVA showed the highest decisiveness in unequivocally reconstructing ancestral ranges, probably reflecting its ability to integrate phylogenetic uncertainty. Care should be taken in defining the palaeogeographical model in DEC because of the possibility of overestimating the frequency of extinction events, or of inferring ancestral ranges that are outside the extant species ranges, owing to dispersal constraints enforced by the model. The wide-spanning spatial and temporal model proposed here could prove useful for testing large-scale biogeographical patterns in plants.

The economically important soapberry family (Sapindaceae) comprises about 1900 species mainly found in the tropical regions of the world, with only a few genera being restricted to temperate areas. The infrafamilial classification of the Sapindaceae and its relationships to the closely related Aceraceae and Hippocastanaceae – which have now been included in an expanded definition of Sapindaceae (i.e., subfamily Hippocastanoideae) – have been debated for decades. Here we present a phylogenetic analysis of Sapindaceae based on eight DNA sequence regions from the plastid and nuclear genomes and including 85 of the 141 genera defined within the family. Our study comprises 997 new sequences of Sapindaceae from 152 specimens. Despite presenting 18.6% of missing data our complete data set produced a topology fully congruent with the one obtained from a subset without missing data, but including fewer markers. The use of additional information therefore led to a consistent result in the relative position of clades and allowed the definition of a new phylogenetic hypothesis. Our results confirm a high level of paraphyly and polyphyly at the subfamilial and tribal levels and even contest the monophyletic status of several genera. Our study confirms that the Chinese monotypic genus Xanthoceras is sister to the rest of the family, in which subfamily Hippocastanoideae is sister to a clade comprising subfamilies Dodonaeoideae and Sapindoideae. On the basis of the strong support demonstrated in Sapindoideae, Dodonaeoideae and Hippocastanoideae as well as in 14 subclades, we propose and discuss informal groupings as basis for a new classification of Sapindaceae.