Abstract Detail

Systematics

Loefstrand, Stefan D. [1], Razafimandimbison, Sylvain G. [2], Rydin, Catarina [3].

Systematics in Coussareeae s.l. (Rubiaceae, Rubioideae).

Coussareeae s.l. are a neotropical clade of morphologically heterogeneous plants in the coffee family (Rubiaceae). The tribe encompasses about 400 spp. assigned to ten genera: Bradea, Coccocypselum, Coussarea, Cruckshanksia, Declieuxia, Faramea, Heterophyllaea, Hindsia, Oreopolus, and Standleya. Historically, the tribe’s genera have rarely been considered closely related and the widely defined Coussareeae were instated as a measure of convenience in the early days of molecular systematics. While the group was until now never the focus of a phylogenetic study, all genera but Bradea and Standleya have been previously represented in phylogenetic analyses and consistently form a monophyletic group, albeit with poorly understood suprageneric relationships and too sparsely sampled to test the monophyly of genera. This study primarily provides a well-sampled phylogeny of Coussareeae s.l. to be combined with literature studies of morphology, karyology and palynology to evaluate the tenability of the current tribal limits. Secondarily, we will perform a focused, more densely sampled, study of Faramea (Coussareeae s.s.) to assess its infrageneric classifications, as well as the monophyly of some of the more widespread species in the genus. General biogeographic patterns will also be discussed based on dating analyses and biogeographic analyses. In lieu of any identified potential common morphological features for Coussareeae s.l., but multiple identified diagnostic features and potential synapomorphies each for Coussareeae s.s. (e.g., single-seeded, but two-locular fruits and porate pollen grains with annuli), Coccocypseleae s.l. (e.g., septicidal fruits and colporate pollen grains with complex reticulate tecta), and Cruckshanksieae s.l. (e.g., strictly pentamerous perianths and chartaceous, few-seeded capsules), we propose resurrecting the latter two and limiting the former one to their original, strict, sense. Results on infrageneric relationships in Faramea are still preliminary, but all sections described in Flora Brasiliensis appear to be non-monohyletic.

1 - Stockholm University, Department of Ecology, Environment and PLant Svciences, Stockholm
2 - Swedish Natural History Museum, Stockholm
3 - Stockholm University, Department Of Ecology, Environment And Plant Sciences, Stockholm, SE-106 91, Sweden

Keywords:
Coccocypseleae
Cruckshanksieae
Faramea
Neotropics.

Presentation Type: Oral Paper
Session: 45, Systematics IV--Caryophs to Euasterids 2
Location: 111/Mayo Civic Center
Date: Wednesday, July 25th, 2018
Time: 2:30 PM
Number: 45005
Abstract ID:609
Candidate for Awards:None