The family Apiaceae (Umbelliferae) can be credited with two major landmarks in botanical history: the first systematic monographic treatment of any plant group (Morison, 1672), and the first international symposium dedicated to systematic research on a plant family (Heywood, 1971). The 1970 symposium on the Biology and Chemistry of the Umbelliferae held at the University of Reading, UK, resulted from the large body of research interest in the family around the world at that time, and helped to stimulate further work on the Apiaceae. It also provided a model for similar symposia on major plant groups in the years to follow, including Asteraceae (Heywood et al., 1977), Brassicaceae (Vaughan et al., 1976), Lamiaceae (Harley & Reynolds, 1992), Solanaceae (Hawkes et al., 1979), and Fabaceae (Summerfield & Bunting, 1980; Polhill & Raven, 1981). Growing interest in umbellifers soon resulted in a second international symposium on the family held at the Centre Universitaire de Perpignan, France, in 1977 (Cauwet-Marc & Carbonnier, 1982). Although a large role of this second symposium was to review progress on a major co-operative research programme focused mainly on the tribe Caucalideae, participants with other interests were also involved, and wider developments in the systematics of the family were discussed.

Phylogenetic relationships involving the angiosperm order Apiales (Apiaceae and Araliaceae) are troublesome at nearly every taxonomic level and have eluded several generations of botanists. Because of difficulties in interpreting and polarizing morphological character states at deeper phylogenetic levels, most studies in Apiales have focused on relationships between the two families and among/within the apialean genera. In the present study, however, recent contributions from molecular analyses are reviewed and combined using a ‘supertree’ approach to test traditional hypotheses of relationships involving Apiales, and to re-evaluate assumptions of character-state evolution in the order. Results from this study confirm that Apiales form a monophyletic group with Pittosporaceae (along with Griselinia G. Forst., Melanophylla Baker, Torricellia DC. and Aralidium Miq.), and should be transferred out of subclass Rosidae (away from both Cornales and Sapindales) to the Asteridae (in a position close to Asterales and Dipsacales). These findings are also supported by several lines of morphological, anatomical, and phytochemical evidence, and provide a more satisfactory framework for interpreting relationships and character-state evolution within the major clades of Apiales.

Wood anatomical data confirm the close relationships of most Araliaceae to Apiaceae, but do not indicate any intermediate groups between the two families. Heteromorpha Cham. & Schltdl., Bupleurum L. and Melanoselinum Hoffm. form a well-delimited group distinguished from other woody Apiaceae by helical thickenings on their vessel walls, septate fibres, and mostly homogeneous rays. The woodiness in Nirarathamnos Balf.f. and Myrrhidendron J. M. Coult. & Rose is likely to be of secondary origin.

Recent molecular studies indicate that the araliaceous tribes Myodocarpeae R. Vig. (Delarbrea Vieill., Pseudosciadium Baill. and Myodocarpus Brongn. & Gris.) and Mackinlayeae R. Vig. (Apiopetalum Baill., Mackinlaya F. Muell. and several genera of Hydrocotyloideae Link (Apiaceae)) comprise basally branching lineages within Apiales, an interpretation consistent with data from morphology and wood anatomy. Comparison of selected features in these genera, and in close relatives of Apiales, suggests that ancestral character states for the order may include: simple leaves, inflorescences in panicles of umbellules, flowers with articulated pedicels and a bicarpellate gynoecium, an andromonoecious, duodichogamous sexual system, septate fibres, the absence of radial canals, and the presence of paratracheal axial parenchyma in the wood.

A preliminary analysis of New Caledonian Araliaceae has shown varying degrees of support for previous hypotheses on sexual system evolution in the family. Andromonoecy, rather than hermaphroditism, is strongly supported as the ancestral sexual system for the Araliaceae. Derivation of hermaphroditism from andromonoecy in Delarbrea harmsii R. Vig. and Polyscias bracteata (R. Vig.) Lowry, ined. is also strongly supported. Support for the derivation of dioecy from andromonoecy in several New Caledonian species of Polyscias J. R. Forst. & G. Forst. depends in part on an assumption that andromonoecy cannot be secondarily derived from dioecy. The derivation of hermaphroditism from andromonoecy in Schefflera candelabra Baill. and S. pseudocandelabra R. Vig. is equivocal. The hypothesis that the immediate ancestors of Arthrophyllum Blume were andromonoecious is not supported.

Systematic relationships within the Hawaiian group Tetraplasandra A. Gray, Munroidendron Sherff and Reynoldsia sandwicensis A. Gray are investigated here based on parsimony analysis of nucleotide sequences from the internal transcribed spacer (ITS 1 and 2) regions and the non-transcribed spacer of 5S (5S-NTS) nuclear ribosomal DNA. Results indicate that Tetraplasandra, Munroidendron and Reynoldsia sandwicensis form a single monophyletic group, and that Reynoldsia A. Gray is paraphyletic. Both data sets support combining Reynoldsia sandwicensis with Munroidendron and treating it as distinct from Reynoldsia species outside Hawaii. Both data sets support two major clades: a Munroidendron/Reynoldsia sandwicensis clade and a Tetraplasandra clade, but they are discordant in relation to the monophyly of Tetraplasandra. 5S-NTS results support treating Tetraplasandra, Munroidendron and Reynoldsia sandwicensis as a single genus, whereas ITS results suggest that Tetraplasandra represents a distinct genus from Reynoldsia sandwicensis and Munroidendron. Tetraplasandra gymnocarpa (Hillebr.) Sherff is the only member of the Araliaceae with a completely superior ovary, and in T. kavaiensis (H. Mann) Sherff the ovary is partially superior. Together, they form a well-supported clade within the Hawaiian complex, confirming the hypothesis that in Tetraplasandra superior ovaries evolved in Hawaii from an epigynous ancestor.

The Aralia–Panax complex consists of three closely related genera of Araliaceae (Aralia L., Panax L. and Sciadodendron Griseb.), widely distributed in temperate, subtropical, and tropical regions of Asia and the Americas. Three major lineages (Panax, Aralia sect. Aralia, and Aralia sect. Dimorphanthus Miq.) are disjunctly distributed in eastern Asia and North America. Comparative sequencing of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA was carried out in order to examine the phylogenetic and biogeographic relationships of this complex. Results suggest Aralia is paraphyletic, with Panax and the Central American monotypic Sciadodendron nested within. The monophyly of Panax (P. trifolius L. maybe excepted), Aralia sect. Aralia (except A. henryi Harms), and Aralia sect. Humiles Harms is supported. The morphologically isolated A. hispida Vent. is embedded within Aralia sect. Dimorphanthus. The phylogenetic data suggest the need to re-examine the generic delimitation of Aralia. None of the presumed intercontinental species pairs between eastern Asia and eastern North America (e.g. Aralia cordata Thunb. and A. racemosa L., A. spinosa L. and A. stipulata Franch., and Panax ginseng C. A. Mey. and P. quinquefolius L.) have been supported as sister species, and the floristic similarity between eastern Asia and eastern North America seems to have been exaggerated by previous workers. Within Aralia sect. Dimorphanthus, the north temperate series Dimorphanthus was paraphyletic, with the subtropical and tropical series Chinensis J. Wen and series Foliolosae J. Wen nested within. This pattern of differentiation is consistent with the hypothesis of morphological stasis among the closely related disjunct taxa between eastern Asia and eastern North America in series Dimorphanthus. Subtropical/tropical Sciadodendron, and Aralia sect. Pentapanax (Seem.) J. Wen are suggested to have derived from temperate elements, although Araliaceae have a generally subtropical and tropical distribution.

Trichomes of Hedera L. taxa have long been used as an important character in delimiting species. Hedera exhibits two distinct trichome types: scale-like and stellate. This study examined the trichome variation in sixteen currently recognized Hedera taxa using scanning electron microscopy. Measurements of trichome morphology were taken, and variation among taxa compared. Of the taxa with scale-like trichomes, H. maderensis Rutherford subsp. maderensis has the largest overall length, longest rays, and largest fusion of rays. Of the species with stellate trichomes, H. helix has the largest overall, and also has the longest rays and widest rays.

Australian Apiaceae, dominated by Hydrocotyloideae Link, are characterized by a number of enigmatic genera, the phylogenetic relationships of which are obscure. A cladistic analysis using morphological and anatomical data indicated that Apiaceae are monophyletic and Hydrocotyloideae form a grade between a paraphyletic Araliaceae and a monophyletic Apioideae Drude+Saniculoideae Burnett. Beyond this, there was no support for past suprageneric arrangements within the order. Hydrocotyleae Spreng. and their constituent subtribes were polyphyletic, as were the subtribes of Mulineae DC. The relationships between Australian genera were not well resolved although the analysis did provide a good indication of broad generic affinities.

A broad overview of the current state of taxonomic knowledge on the Apiaceae of Sub-Saharan Africa and Madagascar is presented. Sub-Saharan Africa has about 69 indigenous genera in the family, with 38 of them endemic, while Madagascar has at least 16 genera, of which six are endemic. Many taxa are poorly known and show unusual combinations of character states. Generic delimitations have not yet reached stability but monographic work, in which morphological, anatomical and some chemical characters are rigorously analysed, is contributing steadily to an improved understanding of generic relationships. A preliminary cladistic analysis of some genera is presented, based on characters such as woodiness, leaf persistence, leaf type, dentate-serrate leaf margins, heteromorphous fruits and the co-occurrence of intrajugal and vallecular vittae. Despite poor resolution, the results consistently show that several African and Madagascan genera are basal to the rest of the Apiaceae. The subfamily Saniculoideae Burnett always appears in a basal position, in close association with anomalous genera such as Lichtensteinia Cham. & Schltdl., Polemanniopsis B. L. Burtt, Steganotaenia Hoscht. and Pseudocarum C. Norman. These genera are clearly central to a better understanding of the early evolution of the family and also to an ultimate improvement of Drude's (1898) classification system.

Phylogenetic analyses of chloroplast gene (rbcL, matK), intron (rpl16, rps16, rpoC1) and nuclear ribosomal DNA internal transcribed spacer (ITS) sequences and chloroplast DNA restriction sites, with supplementary data from variation in size of the chloroplast genome inverted repeat, have been used to elucidate major clades within Apiaceae (Umbelliferae) subfamily Apioideae Drude. This paper summarizes the results of previously published molecular cladistic analyses and presents a provisional classification of the subfamily based on taxonomic congruence among the data sets. Ten tribes (Aciphylleae M. F. Watson & S. R. Downie, Bupleureae Spreng., Careae Baill., Echinophoreae Benth., Heteromorpheae M. F. Watson & S. R. Downie, Oenantheae Dumort., Pleurospermeae M. F. Watson & S. R. Downie, Pyramidoptereae Boiss., Scandiceae Spreng. and Smyrnieae Spreng.) are erected or confirmed as monophyletic, with Scandiceae comprising subtribes Daucinae Dumort., Scandicinae Tausch and Torilidinae Dumort. Seven additional clades are also recognized but have yet to be treated formally, and at least 23 genera examined to date are of dubious tribal or clade placement. The utility of these different molecular markers for phylogenetic inference in Apioideae is compared based on maximum parsimony analyses of subsets of previously published molecular data sets. Of the six loci sequenced, the ITS region is seen to be evolving most rapidly and rbcL is the most conservative. Intermediate in rate of evolution are matK and the three chloroplast introns; with rpl16 and rps16 evolving slightly faster than matK or rpoC1. The analysis of restriction sites, however, provided 2–4 times more parsimony informative characters than any single DNA locus sequenced, with estimates of divergence just slightly lower than that of the ITS region. The trees obtained from separate analyses of these reduced data sets are consistent with regard to the major clades inferred and the relationships among them. Similar phylogenies are obtained by combining data or combining trees, representing the supermatrix and supertree approaches to phylogenetic analysis, respectively. The inferred relationship among the tribes and informally recognized major clades within Apioideae is presented.

Of the 455 known genera in Apiaceae (Umbelliferae), 41% are monotypic and 26% comprise only two or three species each. Similarly, of the 16 genera constituting Scandiceae Spreng. subtribe Scandicinae Tausch, seven (Balansaea Boiss. & Reut., Kozlovia Lipsky, Krasnovia Schischk., Myrrhis Mill., Myrrhoides Fabr., Sphallerocarpus DC. and Todaroa Parl.) are monotypic, and two (Neoconopodium Pimenov & Kljuykov and Tinguarra Parl.) are bitypic. Phylogenetic analysis of the subtribe, using molecular (rDNA ITS), morphological and anatomical data, indicates that the number of genera may be reduced with only three, Todaroa, Sphallerocarpus and Myrrhis, retained as monotypic. Remaining taxa form eight clades that are supported by high bootstrap values and are morphologically distinct. Four of these clades (Anthriscus Pers., Geocaryum Coss., Osmorhiza Raf. and Scandix L.) are equivalent to currently recognized genera. Kozlovia, Krasnovia and Neoconopodium form a well-supported clade that may be recognized as the single genus Kozlovia, and Myrrhoides is grouped with Chaerophyllum L. Tinguarra and Athamanta L. form a monophyletic group that is well supported by analyses of morphology, fruit anatomy, and combined morphological, anatomical and ITS sequence data; however, this group is not maintained in separate analyses of ITS sequences. Similarly, the group formed by Conopodium W. D. J. Koch and Balansaea is monophyletic in morphological, anatomical, and combined analyses, but is not supported by the separate analyses of ITS sequence data. All of these groups are well delimited on the basis of fruit characters that have long been regarded as essential in umbellifer taxonomy. One new combination is proposed: Athamanta montana (Webb ex H. Christ.) Spalik, A. Wojew. & S. R. Downie.

Plant conservation genetics has been hampered by a lack of markers for studies of levels and patterns of variation in rare species. We investigated the levels of variation in several rare and widespread species of the western North American genus Lomatium Raf. (Apiaceae) using two relatively new molecular markers: AFLPs and single-strand conformation polymorphisms (SSCPs). For each species, approximately 150 AFLP loci have been scored, yielding estimates of species-level percent polymorphic loci in rare species ranging from near zero to over 80%. Levels of AFLP diversity were similar in two of the rare species, L. bradshawii (Rose ex Mathias) Mathas & Constance and L. ochocense Helliwell & Constance, and the widespread species. The third rare species, L. cookii Kagan, which has small populations, has low levels of diversity based on AFLPs. We also examined nucleotide diversity at the single-copy nuclear-DNA locus glyceraldehyde 3-phosphate dehydrogenase (Gap-C). PCR-amplified segments were analysed for allelic variation using SSCPs, and intrapopulational nucleotide polymorphisms were identified in both L. bradshawii and L. cookii. In the 211bp segment of Gap-C analysed, five nucleotide sites were segregating within populations of L. bradshawii and two in L. cookii.