Phylogenetic relationships in the Neotropical tribe Hamelieae (Rubiaceae, Cinchonoideae) and comments on its generic limits

Abstract

Our molecular phylogenetic analyses shed some light on the evolutionary relationships within the Hamelieae tribe. Phylogenetic reconstructions based on Internal Transcribed Spacer and trnL‐F sequence data revealed the presence of three distinct evolutionary lineages. The first clade includes Hamelia and Syringantha, the second clade includes Deppea s.l. (including Bellizinca, Csapodya, and Edithea), and the third clade includes Pinarophyllon, Deppeopsis, Hoffmannia, Pseudomiltemia, Plocaniophyllon, Omiltemia, and Renistipula. The phylogenetic analysis re‐evaluated some taxonomical combinations. The transfer of Deppeopsis taxa from Deppea s.l. is supported, but however, the monophyly of the genus is not. The transfer of Renistipula from Rondeletieae is also highly supported. Both Csapodya and Edithea species form a well‐defined group among Deppea s.l. with high posterior probabilities, allowing to reconsider the exclusion or integration of these taxa to Deppea.

Seed morphology of Hamelieae with emphasis on the Deppea complex (Cinchonoideae, Rubiaceae)

“…A phylogenetic analysis by Torres-Montúfar (2018) however placed Renistipula within Guettardeae and treated it as a synonym of Arachnothryx Planch. All morphological evidence indicates that Renistipula belongs in Guettardeae and so we favour the results by Torres-Montúfar (2018), suggesting that the results by Stranczinger et al (2014) are most likely an artifact of a methodological error.…”

“…Hamelieae is a Neotropical tribe comprising 16 genera and approximately 225 species, notably diverse in Mexico where it has 14 genera and ca 100 species (Lorence & Dwyer 1988;Borhidi 2006Borhidi , 2012. It is characterized by shrubs or treelets, presence of raphides, typically ebracteolate inflorescences, often yellow or yellowish 4-merous flowers, contorted corolla aestivation, and berries or capsular fruits (Bremer 1987;Borhidi et al 2004aBorhidi et al , 2004bManns & Bremer 2010;Stranczinger et al 2014).…”

“…Molecular phylogenetic analyses retrieved a monophyletic and highly supported Hamelieae but did not solve the Deppea taxonomic problem: Manns & Bremer (2010) used a set of six markers (nrITS,ndhF,rbcL,rps16,, but only studied six genera of the Deppea complex with a few species each, leaving many questions related to their generic circumscription open. Stranczinger et al (2014), on the other hand, included representatives of all genera in the Deppea complex, but they only used two markers (ITS and trnL-F) resulting in a consensus tree with many polytomies that made the taxonomic decisions untenable. Their phylogenetic analysis showed that none of the genera in the Deppea complex were supported as monophyletic and that the genus Renistipula Borhidi should be included as a member of Hamelieae despite its lack of the diagnostic raphides.…”

Las Rubiáceas de México: ¿Ya está hecho el trabajo?

“…Esta segregación no fue aceptada en Flora Mesoamericana por Lorence (2012) en la cual se tratan como sinónimos. Estudios moleculares recientes son contradictorios, por un lado, Stranczinger et al (2014) ubica a Renistipula en la tribu Hamelieae en lugar de Guettardeae, pero no se incluyeron otras muestras de Guettardeae y menos de Arachnothryx, además que Renistipula no presenta ninguna de las características morfológicas que definen Hamelieae como las inflorescencias ebracteadas, flores amarillas y la presencia de rafidios (Robbrecht 1988). Por otro lado, Torres-Montúfar (2018) encuentra ambos géneros formando un mismo clado sin resolución en Guettardeae, resultado que apoya su sinonimia.…”

“…De acuerdo con Lorence (2012), estos taxones se consideran como sinónimos de Deppea por su morfología vegetativa no obstante las claras diferencias en el tamaño y forma de la corola atribuibles a adaptaciones a la polinización por colibríes (Lorence & Dwyer 1988). La evidencia molecular apoya la conclusión de Lorence (2012), ya que los tres géneros se recuperan en un clado sin resolución con las especies de Deppea (Manns & Bremer 2010, Stranczinger et al 2014. En el presente trabajo se reconocerán estos tres géneros por las evidentes diferencias morfológicas florales, aunado a que los trabajos filogené-O n l i n e f i r s t ticos carecen de una adecuada representación de taxones o un pobre muestreo de caracteres, por lo cual no es robusta la conclusión de sinonimizarlos todos en un solo género.…”