Disintegrating Portulacaceae: A new familial classification of the suborder Portulacineae (Caryophyllales) based on molecular and morphological data

Abstract

Traditional classifications of the suborder Portulacineae recognize six families: Basellaceae, Cactaceae, Didiereaceae, Halophytaceae, Hectorellaceae, and Portulacaceae. However, phylogenetic analyses based on molecular sequence data indicate that the traditional family Portulacaceae is paraphyletic and consists of three distinct lineages that also include Cactaceae, Didiereaceae, and Hectorellaceae. We use sequence data from the chloroplast genes matK and ndhF representing 64 species of Portulacineae and outgroups to reconstruct their phylogenetic relationships with Bayesian and maximum parsimony inference methods. Evidence from these molecular phylogenetic analyses as well as from comparative morphological investigations allow us to propose a revised familial classification of the suborder Portulacineae. We recognize eight monophyletic families: We provide a synopsis for this revised family classification with an identification key mainly based on habit and fruit characters, and family diagnoses with information on distribution, taxonomic diversity, and a brief discussion on phylogenetics and classification.

Complex Evolutionary Transitions and the Significance of C3-C4 Intermediate Forms of Photosynthesis in Molluginaceae

“…(Tropicos 2010) should possibly be resurrected for H. spergulacea . Molluginaceae are highly supported as the sister group of the Portulacineae clade (Nyffeler et al 2008; Nyffeler and Eggli, 2010) and contain the genera Mollugo , Adenogramma , Coelanthum , Glinus , Glischtrothamnus , Pharnaceum , Polpoda , Psammotropha , and Suessenguthiella , and H. spergulacea (Figs. 2 and 3).…”

Molecular systematics of the Cactaceae

“…Note that throughout we follow the taxonomy of the New Cactus Lexicon (Hunt, 2006), using only species names accepted in this source. The taxonomic distribution of samples represented in our final matrix is summarised in Table 2. Recent studies have shown the Cactaceae to be a wellsupported monophyletic group most closely related to family Anacampserotaceae (formerly tribe Anacampseroteae; Nyffeler and Eggli, 2010) and the genera Portulaca and Talinum of the family Portulacaceae (Nyffeler, 2007). We include sequences previously published by Nyffeler (2002) to represent these groups, Grahamia bracteata of the Anacampserotaceae, Portulaca oleracea, and Talinum paniculatum.…”

Revealing diversity in structural and biochemical forms of C4 photosynthesis and a C3-C4 intermediate in genus Portulaca L. (Portulacaceae)

“…In Portulacaceae, which has 29 genera as traditionally circumscribed (Eggli, 2002; but see Nyffeler and Eggli, 2010 for an alternative circumscription), only Portulaca is known to have C 4 species. Previous suggestions that some species of Anacampseros and Grahamia may be C 4 are not supported by a recent study (Guralnick et al , 2008), which indicates the occurrence of Crassulacean acid metabolism (CAM) rather than C 4 photosynthesis in these genera.…”