Therps16 intron and the phylogeny of theRubioideae (Rubiaceae)

The phylogeny of the subfamilyRubioideae (Rubiaceae) was estimated from sequence variation in therps16 intron (cpDNA) in 143 ingroup and 5 outgroup taxa. The analysis largely confirms a recent one based onrbcL sequences, but branch support is often much stronger. Three of the traditional subfamilies are supported,Rubioideae, Cinchonoideae s. str., andIxoroideae s. l. while there is no support forAntirheoideae. TheRubioideae are the sister group of all otherRubiaceae and comprise the tribesAnthospermeae, Coccocypseleae, Cruckshanksieae, Coussareeae, Gaertnereae, Hedyotideae, Knoxieae, Morindeae, Ophiorrhizeae, Paederieae, Pauridiantheae, Perameae, Psychotrieae, Rubieae, Spermacoceae, Theligoneae, andUrophylleae. TheHamelieae andHillieae belong to theCinchonoideae. Rachicallis andSiemensia should be transferred from theHedyotideae to theCinchonoideae. ThePauridiantheae, Urophylleae, Ophiorrhizeae, andRaritebe form the basalmost subclade of theRubioideae. The second basalmost clade consists of the generaLasianthus andPerama. The third basalmost clade consists of the tribesCoussareeae, Coccocypseleae andCruckshanksieae, and the generaDeclieuxia andHindsia. The tribesKnoxieae, Anthospermeae, Argostemmateae, Paederieae, Theligoneae, Rubieae, Hedyotideae, andSpermacoceae are members of one clade. TheKnoxieae are monophyletic ifOtiophora, Otomeria, andPentas are included. The tribeAnthospermeae is supported as monophyletic, but its subtribes are not. ThePaederieae, together withTheligonum, form a paraphyletic grade basal to theRubieae. TheHedyotideae, includingSchismatoclada, form a grade at the base of theSpermacoceae. TheGaertnereae are monophyletic and distinct from thePsychotrieae. TheMorindeae are monophyletic and includeDamnacanthus andMitchella. Schradera is the sister group of theMorindeae. ThePsychotrieae are monophyletic when theGaertnereae, Lasianthus, andDeclieuxia are excluded. The recognition of a subtribeHydnophytineae leaves the rest of thePsychotrieae paraphyletic.Psychotria is paraphyletic with respect to all other genera of the tribe. Approximately 50 genera are here classified for the first time based on molecular data.