De Luna E. 2021

A synopsis of Braunia (Hedwigiaceae, Bryopsida) in Mexico, with the lectotypification of Braunia andrieuxii. ACTA BOTANICA MEXICANA 128: e1950. PDF. 
DOI: https://doi.org/10.21829/abm128.2021.1950 

Abstract: 

Background and Aims: Four species of Braunia are known in Mexico: Braunia andrieuxii, B. secunda, B. squarrulosa and B. plicata. A taxonomic study of the species of Braunia in Mexico has not been undertaken before. Moreover, among several “Andrieux” specimens currently available, there is no certainty as to which particular collection is the type. 

Methods: The four species of Braunia known in Mexico and neighboring areas in the southern United States of America, Central America and the Caribbean Islands were studied together for the first time. Based on over 450 collections from several herbaria, a taxonomic treatment and a key to the species of Braunia in this geographical region are presented. 

Key results: The four species are described and illustrated. A specimen Andrieux 23 located at BM is selected as the lectotype for B. andrieuxii, with isolectotypes in the herbaria BM and NY. A key is provided for the identification of the species of Braunia in Mexico, and neighboring USA, Central America, and the Caribbean. 

Conclusions: Morphological features most likely to be informative for the distinction of the four species in Mexico are the leaf margins, leaf apices, upper leaf cells, and sporophytes. The leaf apex is hyaline and dentate only in B. plicata, while it is concolorous and entire or scabrous in the other three species of Braunia from Mexico. The upper leaf cells are quadrate to short- rectangular in B. andrieuxii and B. plicata; whereas the upper leaf cells are elongate in B. secunda and B. squarrulosa. 

Key words: Hedwigiales, mosses, taxonomy.

Dynamic zoomable maps are shared on line here (thanks to ZeeMaps): 

 

http://www.filogenetica.org/Hedwigiaceae/Braunia~squarrulosa.htm

http://www.filogenetica.org/Hedwigiaceae/Braunia~secunda.htm

http://www.filogenetica.org/Hedwigiaceae/Braunia-plicata.htm

http://www.filogenetica.org/Hedwigiaceae/Braunia-andrieuxii.htm

De Luna E. 2021

Seta length variation and the refutation of Hedwigidium = Braunia (Hedwigiaceae, Bryopsida). ACTA BOTANICA MEXICANA 128: e1810. PDF. 

DOI: https://doi.org/10.21829/abm128.2021.1810 xml 

Abstract: 

Background and Aims: Traditionally regarded as a monotypic genus, Hedwigidium was recently proposed to be identical to Braunia, because “… some Braunia species have a seta as short as that of Hedwigidium.” This paper offers data and analyses for a refutation of the taxonomic hypothesis that Hedwigidium = Braunia. 

Methods: Seta length measurements (n=682) were sampled in 20 species of the four genera of Hedwigiaceae to compare variation between Hedwigia (n=10), Hedwigidium (n=40), Braunia (n=614), and Pseudobraunia (n=18). Measurements were subjected to analyses of variance and multiple comparison tests, to reveal if some Braunia species have a seta as short as that of Hedwigidium, or not. 

Key results: Analyses of variance followed by Mann-Whitney pairwise tests reveal that the average seta length in Hedwigidium imberbe (0.7 mm, sd=0.21) is different from the average seta length in each of the seven Braunia species with short setae, all in the range of 2.0-2.3 mm. For the first time, the geographical distribution of Hedwigidium is documented and mapped. Literature records are verified for Europe (United Kingdom, Norway, France, Italy, and Spain), Africa (Cameroon, DR Congo, Malawi, Tanzania, Uganda, Zimbabwe, South Africa, Reunion Island, Kenya), and Southeast Asia (India, Sri Lanka, Indonesia). In the New World, Hedwigidium is confirmed for Mexico, Guatemala, El Salvador, Honduras, Costa Rica, Dominican Republic, and South America (Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, Argentina, and Brazil). 

Conclusions: The data and statistical analyses presented here refute the taxonomic conclusion proposing Hedwigidium is synonymous with Braunia. None of Braunia species has a seta as short as that of Hedwigidium. Therefore, still surviving unrefuted is the alternative hypothesis that Hedwigidium is a separate genus. Taxonomic characters important in distinguishing this genus from other genera in the Hedwigiaceae are discussed. 

 Key words: Braunia, Hedwigia, Hedwigiales, morphometrics, refutation.