Taxonomic revision of Ornithogalum subg. Ornithogalum (Hyacinthaceae) in the Iberian Peninsula and the Balearic Islands

The taxonomic arrangement within subfamily Ornithogaloideae (Hyacinthaceae) has been a matter of controversy in recent decades: several new taxonomic treatments have been proposed, based exclusively on plastid DNA sequences, and these have resulted in classifications which are to a great extent contradictory. Some authors have recognized only a single genus Ornithogalum for the whole subfamily, including 250-300 species of variable morphology, whereas others have recognized many genera. In the latter case, the genera are inevitably much smaller and they are better defined morphologically. However, some are not monophyletic as circumscribed. Phylogenetic analyses of Ornithogaloideae were based on nucleotide sequences of four plastid regions (trnL intron, trnL-F spacer, rbcL and matK) and a nuclear region (ITS). Eighty species covering all relevant taxonomic groups previously recognized in the subfamily were sampled. Parsimony and Bayesian analyses were performed. The molecular data were compared with a matrix of 34 morphological characters. Combinations of plastid and nuclear data yielded phylogenetic trees which are better resolved than those obtained with any plastid region alone or plastid regions in combination. Three main clades are found, corresponding to the previously recognized tribes Albuceae, Dipcadieae and Ornithogaleae. In these, up to 19 clades are described which are definable by morphology and biogeography. These mostly correspond to previously described taxa, though some need recircumscription. Morphological characters are assessed for their diagnostic value for taxonomy in the subfamily. On the basis of the phylogenetic analyses, 19 monophyletic genera are accepted within Ornithogaloideae: Albuca, Avonsera, Battandiera, Cathissa, Coilonox, Dipcadi, Eliokarmos, Elsiea, Ethesia, Galtonia, Honorius, Loncomelos, Melomphis, Neopatersonia, Nicipe, Ornithogalum, Pseudogaltonia, Stellarioides and Trimelopter. Each of these has a particular syndrome of morphological characters. As a result, 105 new combinations are made and two new names are proposed to accommodate the taxa studied in the new arrangement. A short morphological diagnosis, synonymy, details of distribution and an identification key are presented.

A revised generic synopsis of sub-Saharan Hyacinthaceae is presented, based on a molecular phylogenetic analysis of the family. Generic rank is accorded only to reciprocally monophyletic clades that can be distinguished by recognizable morphological discontinuities, thereby permitting an appropriate generic assignment of species not included in the analysis. Three subfamilies are recognized within the region. Subfamily Ornithogaloideae , characterized by flattened or angular seeds with tightly adhering testa, is considered to include the single genus Ornithogalum , which is expanded to include the genera Albuca, Dipcadi, Galtonia, Neopatersonia and Pseudogaltonia . Recognizing any of these segregates at generic level renders the genus Ornithogalum polyphyletic, while subdivision of Ornithogalum into smaller, morphologically distinguishable segregates in order to preserve the monophyly of each is not possible. Subfamily Urgineoideae , characterized by flattened or winged seeds with brittle, loosely adhering testa, comprises the two mainland African genera Bowiea and Drimia . The latter is well circumscribed by its deciduous, short-lived perianth and includes the previously recognized genera Litanthus, Rhadamanthus, Schizobasis and Tenicroa . The monotypic Madagascan Igidia is provisionally included in the subfamily as a third genus on the basis of its seeds, pending molecular confirmation of its relationships. Subfamily Hyacinthoideae resolves into three clades, distinguished as tribes Hyacintheae (strictly northern hemisphere and not treated further), Massonieae and Pseudoprospereae tribus nov. Full descriptions and a key to their identification are provided for all genera. New combinations reflecting the generic circumscriptions adopted here are made for most African and all Indian and Madagascan species.