Abstract Detail


Comito, Robert [1].

Evolution, Diversification, and Conservation Implications in the Pantropical Clade Barlerieae (Acanthaceae).

Among Acanthaceae (ca. 4,000 spp.), Barlerieae (ca. 440 spp.) is a tribe that needs considerable further study. Barlerieae contain 13 genera, the two largest and most widespread of which are Barleria (ca. 300 spp., primarily paleotropical), and the pantropical Lepidagathis (ca. 100 spp.). Sub-Saharan Crabbea includes 14 species. The remaining ten genera, with ~25 species in all, are distributed across Latin America, South Asia, Africa, and Madagascar. Barlerieae present several taxonomic problems, and some species have intriguing biogeographic patterns (e.g., a few species, such as Lepidagathis alopecuroides, have amphi-Atlantic distributions). Many species in this group are important to tropical ecosystems and support a wide range of pollinators. In a recent reclassification of Acanthaceae, three subtribes have been proposed based on corolla and calyx characters: (1) Barleria, (2) Crabbea and allies, and (3) Lepidagathis and allies. Using a next-generation sequencing (NGS) approach (ddRADseq), I will: (1) estimate a well-sampled phylogeny of the tribe to test current taxonomy as well as proposed classifications, (2) test genera and sub-generic groups for monophyly, (3) identify morphological characters that support monophyletic groups, (4) examine patterns of biogeography and diversification, and (5) address conservation concerns and prospects in a phylogenetic context. Initial data indicate that Barlerieae, as recognized by the developmental character quincuncial corolla aestivation, is monophyletic. In addition, data suggest a major taxonomic revision of Lepidagathis is necessary. Species of Lepidagathis are found in three clades: Lepidagathis s.s., including species with bithecous posticous anthers, species formerly recognized as Lophostachys + Lepidagathis with monothecous posticous anthers; and the widespread species Lepidagathis aloepecuroides. The phylogenetic relationships recovered here suggest each clade may merit recognition at the generic level. In addition, L. aloepecuroides is found to be monophyletic with sampling across its range in Africa and South America. Also, the placement of several small genera endemic to Madagascar, a biodiversity hotspot, are resolved for the first time. Ultimately, this research will contribute to taxonomic revisions and updated keys that will aid in conservation efforts and provide insight into the evolutionary processes that shape biodiversity in this remarkable lineage.

1 - California Botanic Garden, ‍1500 N College Avenue, ‍1500 N College Avenue, Claremont, CA, 91711, United States

Tropical Botany

Presentation Type: Oral Paper
Number: SYST III002
Abstract ID:260
Candidate for Awards:None

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