A phylogenetic study of the Plantaginaceae

Abstract

In a study based on morphological, embryological and chemical data of the Plantaginaceae, within the subclass Sympetalae or Asteridae, the superorder Lamianae is shown to be monophyletic. However, it was nor possible to reconstruct the phylogeny within Lamianae or to find a sister-group for the monophyletic Plantaginaceae - Hydrostachyaceae for the latter is rejected. Three or rarely four genera have previously been recognized within Plantaginaceae, but in both cases Plantago appears as polyphyletic, which is considered unacceptable. Six clades are recognized as subgenera within Plantago: subgen. Plantago (c. 131 species), subgen. Coronopus (c. 11 species), subgen. Littorella (three species), subgen. Psyllium (c. 16 species), subgen. Bougueria (one species), and subgen. Albicans (51 species). Within P. subgen. Plantago, the paraphyletic sect. Plantago (c. 42 species) is found in all parts of the world except South America, New Zealand, Australia, and New Guinea, where sect. Oliganthos and sect. Mesembryniae vicariate. It is not possible to infer the phylogeny within sect. Plantago, for example between the endemic species from distant Pacific Islands; their common ancestor might be a species that once had a very wide distribution. Keys to genera, subgenera, sections and series are given. Only one genus, Plantago L., is recognized. The following proposals are made in the Appendix: P. ser. Oliganthos Rahn, ser. nov.; P. ser. Carpophorae (Rahn) Rahn, stat. nov. (= sect. C.); P. ser. Microcalyx (Pilg.) Rahn, stat. nov. (= sect. M.); P. unibracteata Rahn, nom. nov. (= P. uniflora Hook.f. non L.); P. subgen. Littorella (P.J. Bergius) Rahn, stat. nov. (= Littorella P.J. Bergius); P. araucana Rahn, nom. nov. (= Littorella australis Griseb. non Plantago australis Lam.); P. americana (Fernald) Rahn, comb. nov.(= Littorella a.); P. subgen. Bougueria (Decne.) Rahn, stat. nov. (= Bougueria Decne.); P. nubicola (Decne.) Rahn, comb. nov. (= Bougueria n. Decne.); P. subgen. Albicans Rahn, subgen. nov. Ten lectotypes are selected. (C) 1996 The Linnean Society of London