The results of phylogenetic analyses of 1240 nrDNA ITS sequences of Apiaceae subfamily Apioideae, representing 292 genera and 959 species from all major clades of the subfamily except those most basally branching, were compared to a preexisting phylogenetic classification for the group based on several molecular markers and a smaller sampling of taxa. This was done to confirm previously defined tribal and generic limits and to identify additional major clades and genera whose monophyly and relationships can be tested in future studies. All species for which ITS data are available in Gen-Bank plus newly obtained sequences for 53 additional taxa were considered for inclusion in this study and their simultaneous analysis permitted misidentifications and other problematic sequences to be revealed. Analyses of these ITS data, in conjunction with results of recently published molecular studies, identified 41 major clades in Apioideae, of which 21 have already been recognized at the tribal or subtribal rank. No major changes to the preexisting phylogenetic classification of Apioideae are proposed, other than the recognition of additional major clades and the expansion of others to accommodate increased sampling. As noted in previous studies, many genera are not monophyletic; indeed, 18 genera are highly polyphyletic, with their members occurring in 2 to 7 major clades. Each of the 1240 accessions examined can be unambiguously assigned to a particular major clade. Resolution of relationships, as well as the formal recognition of several major clades, must await supporting data, such as that from the cpDNA trnQ (UUG)-5'trnK (UUU) intergenic spacer region. An ITS-based classification of the subfamily is proposed that enables direct and precise references to specific groups and facilitates sampling and hypothesis testing in future systematic studies.

Scandiceae subtribe Daucinae encompasses umbellifers that have fruits with prominent secondary ridges projecting into wings (former tribe Laserpitieae) or spines (former tribe Caucalideae pro parte). It comprises several economically or medicinally important genera including Cuminum, Daucus, Laser, Laserpitium and Thapsia among others. Recent molecular studies, based mostly on nrDNA ITS sequences, revealed that neither Daucus nor Laserpitium are monophyletic. To address issues of relationships and apply respective nomenclatural changes, we obtained additional ITS sequences as well as independent data from three plastid markers—rps16 intron, rpoC1 intron and rpoB‐trnC intergenic spacer—for a comprehensive sample of the subtribe. We examined data for 260 accessions representing all genera of Daucinae and 81 of its ca. 93 species. Phylogenetic trees were estimated using maximum likelihood and Bayesian inference methods. The results indicate that former Laserpitieae constitute a paraphyletic grade at the base of the spiny‐fruited members of Daucinae while traditionally delimited Daucus and Laserpitium are polyphyletic. To maintain a monophyletic Daucus, we suggest including the following genera and species into its synonymy: Agrocharis, Melanoselinum, Monizia, Pachyctenium, Pseudorlaya, Rouya, Tornabenea, Athamanta dellacellae and Cryptotaenia elegans. The species of Laserpitium occur in seven clades and only six species of the Laserpitium s.str. clade retain the generic name. Several species are transferred to Ekimia, Laser and Thapsia; additionally, a monospecific genus Siler is restored and a new genus, Silphiodaucus, is established. The inclusion of Ammodaucus into Thapsia suggested in an earlier study is not supported. The position of Laserpitium pseudomeum requires further study.

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Premise Despite intensive research, the pathways and driving forces behind the evolution of derived woodiness on oceanic islands remain obscure. The genus Daucus comprises mostly herbs (therophytes, hemicryptophytes) with few rosette treelets (chamaephytes) endemic to various Macaronesian archipelagos, suggesting their independent evolution. To elucidate the evolutionary pathways to derived woodiness, we examined phylogenetic relationships and the habit and secondary xylem evolution in Daucus and related taxa. Methods Sixty taxa were surveyed for molecular markers, life history, and habit traits. Twenty‐one species were considered for wood anatomical characters. A dated phylogeny was estimated using Bayesian methods. The evolution of selected traits was reconstructed using parsimony and maximum likelihood. Results Daucus dispersed independently to the Canary Islands (and subsequently to Madeira), Cape Verde, and the Azores in the late Miocene and Pleistocene. Life span, reproductive strategy, and life form were highly homoplastic; the ancestor of Daucus was probably a monocarpic, biennial hemicryptophyte. Rosette treelets evolved independently in the Canarian‐Madeiran lineage and in Cape Verde, the latter within the last 0.13 Myr. Treelets and hemicryptophytes did not differ in wood anatomy. Pervasive axial parenchyma in wood occurred more often in polycarpic rather than monocarpic species. Conclusions Life span and life form in Daucus are evolutionarily labile and may change independently of wood anatomy, which is related to plant reproductive strategy rather than to life form. Insular woodiness may evolve rapidly (as demonstrated in D. bischoffii), and in Daucus, it does not seem to be an adaptation to lower the risk of xylem embolism.

Factors influencing diversification rates may be of intrinsic (e.g. morphological novelties) or extrinsic (e.g. long-distance dispersal, availability of ecological niches) nature. Growth habit may influence diversification rates because herbaceous plants often have shorter generation times and a more pronounced r reproductive strategy than their woody relatives. We examined life history and habit evolution, wood anatomy and biogeographical history of Apiaceae tribe Apieae in conjunction with diversification rate analysis to explore which factors may have affected clade species richness and to elucidate the constraints on the evolution of secondary woodiness in this group. We demonstrate that diversification rates are similar in morphologically homogeneous and diverse clades and in herbaceous and woody lineages. The only clade with a significantly elevated diversification rate is Southern Hemisphere Apium, in which diversity probably resulted from several long-distance dispersal events. We also show that wood anatomy in herbaceous and woody species does not differ considerably regardless of their continental or insular origin, but it is affected by stem architecture and plant reproductive strategy. As the taxonomy of Apieae suffers from inflation with numerous monotypic genera, we propose to include Canaria in Rutheopsis, and Foeniculum, Schoenoselinum, Ridolfia and Pseudoridolfia in Anethum.