Further disintegration of Scrophulariaceae

Lamiales sensu APG II (The Angiosperm Phylogeny Group, 2003) constitute a major clade of flowering plants, with approximately 17,800 species (Judd & al., 2002) and 23 families, representing 12.3% of eudicot diversity (Stevens, 2001, onwards). They belong to a major asterid clade, the Lamiids (Bremer & al., 2002). The monophyly of Lamiales is comparatively uncontroversial and well supported by molecular (e.g., Backlund & al., 1998; Oxelman & al., 1999; Albach & al., 2001; Bremer & al., 2002) and phytochemical data (Jensen, 1992; Scogin, 1992). Morphologically, they typically are characterized by opposite leaves, sympetalous zygomorphic flowers, oligosaccharides, frequent production of 6oxygenated flavones, embryos of Onagrad type and capsular fruits. Although the majority of the many wellknown families in Lamiales are well supported (e.g., Olmstead & al., 2001), the relationships among them are obscure, despite several recent molecular studies (e.g., Olmstead & Reeves, 1995; Backlund & al., 1998; Oxelman & al., 1999; Olmstead & al., 2001). The concept “Scrophulariae” occurs in Durande, Notions Elém. Bot.: 265. 1782, but the name of the family is conserved as Scrophulariaceae Jussieu. The most influential classifications for the 19th century concept of Scrophulariaceae were those of Bentham (1846), who in addition recognized Selaginaceae Choisy, Wettstein (1895), who recognized Lentibulariaceae, Plantaginaceae, and Orobanchaceae as separate families, and Hallier (1903), who made the broadest circumscription of the family. Even if doubts sometimes were expressed regarding the naturalness of Scrophulariaceae (e.g., Thieret, 1967; Barringer, 1984), it was not until the study by Olmstead & Reeves (1995) based on plastid ndhF and rbcL gene sequences that the concept of Scrophulariaceae needed a revolutionary revision in order to fit within a phylogenetic framework. Olmstead & Reeves (1995) discovered two clearly separated clades consisting of scrophulariaceous taxa. One clade (“scroph I”) included Buddleja L., Selago L., Verbascum L. and the type genus Scrophularia L., whereas the other (“scroph II”) included Antirrhinum L., Digitalis L., Veronica L., Plantago L., Hippuris L., and Callitriche L. In their study the enigmatic woody Paulownia Siebold & Zucc., which was usually classified in Scrophulariaceae but transferred to Bignoniaceae Juss. by Takthajan (1980), and Schlegelia Miq., which was originally placed in Bignoniaceae but argued by Armstrong (1985) to fit better within