Abstract
Field studies of the inselberg flora of north-eastern Brazil have resulted in the discovery of much greater morphological diversity of the genus Ameroglossum, than previously envisaged. These enigmatic plants are endemic to isolated rock outcrops, which have long been surrounded by unsuitable habitat. The morphological forms are geographically isolated and stable in cultivation when grown under similar conditions. We here provide detailed descriptions of the two previously known species and propose an additional seven new species in the genus. A taxonomic revision of the genus, including an identification key is provided. We hypothesize that the evolution of this genus is driven by the diversity of their hummingbird pollinators. Due to the threatened nature of inselberg habitats and the small populations found for most taxa, the species described here are likely to be under threat and in need for formal redlisting.
Highlights
On March 12, 1958, Dárdano de Andrade-Lima collected an unusual ‘Scrophulariaceae’ in Quipapá, Pernambuco State, Brazil
Specimens of the collected material were described as the genus Ameroglossum Eb.Fisch., S.Vogel & A.V.Lopes (Fischer et al 1999) based on its undivided lip [etymology: from Greek αμέρος, undivided, and γλώσσα, tongue]
Field collections were undertaken on rock outcrops in the geomorphological structure of the Borborema Plateau, which covers parts of the Brazilian states of Rio Grande do Norte, Paraíba, Pernambuco and Alagoas (Fig. 1)
Summary
On March 12, 1958, Dárdano de Andrade-Lima (coll. no. 50-600, IPA!) collected an unusual ‘Scrophulariaceae’ in Quipapá, Pernambuco State, Brazil. Preliminary molecular and morphological studies (in preparation) suggest that Ameroglossum is related to Cubitanthus Barringer (1984) and Stemodiopsis Engler (1897), formerly placed in Gesneriaceae and Scrophulariaceae, respectively These genera are known to belong to Linderniaceae (Fischer et al 2013; Christenhusz et al 2017), and several characters appear to be shared by Ameroglossum and this clade (Almeida et al 2019). & E.M.Almeida (in Almeida et al 2019), with the latter genus having the greatest affinity to Ameroglossum in preliminary molecular studies (not presented here) In addition to these two new genera, many new populations of Ameroglossum have been discovered, which exhibit a greater morphological diversity than previously known. An amended description of Ameroglossum and a diagnostic key to the species are provided
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
