Recognize Baja (segregated from Cheilanthes) [PASSED]

Author(s) of proposal

No response

Name of taxon

Baja

Rank of taxon

Genus

Approximate number of species affected

Description of change

Transfer the species long known as Cheilanthes brandegeei D.C. Eaton to the (monotypic) genus Baja.

Reason for change

Endemic to Baja California, Mexico, is an enigmatic cheilanthoid long treated as Cheilanthes brandegeei D.C. Eaton. Phylogenetic analyses (George et al. 2019) however, demonstrate that this species, together with its sister lineage, Bommeria, constitutes a deeply isolated lineage within cheilanthoids, far from the hemionitid clade that contains the type of Cheilanthes (Windham et al. 2009). However, Bommeria is quite different, morphologically, from the brandegeei taxon (most conspicuously brandegeei has pinnately divided leaves vs the entire leaves of Bommeria, and a well-developed false indusium whereas the sori in Bommeria are acrostichoid), and thus George et al. created a new genus for it: Baja.

The only alternatives, in terms of recognizing ony monophyletic taxa, would be to treat brandegeei in Bommeria, where it is morphologically anomalous (and thus reducing the cohesiveness and diagnosability of Bommeria) or to extend the circumscription of Cheilanthes to encompass both the generic type and brandegeei. However, this enlarged "Cheilanthes" clade would include nearly all cheilanthoids (only Calciphilopteris would remain unaltered) and would need to be treated as Hemionitis rather than Cheilanthes (Hemionitis is the older name so has priority).

George et al. - 2019 - Baja A New Monospecific Genus Segregated .pdf Windham et al. - 2009 - Using plastid and nuclear DNA sequences to redraw .pdf

Reference(s) for publication of the name

George et al. - 2019 - Baja A New Monospecific Genus Segregated .pdf

List the numbers of any related issues

No response

Code of Conduct

[X] I agree to follow the PPG Code of Conduct

pteridogroup / ppg