Morphological and molecular evidences to segregation a disjunct species of Hymenophyllum ( Hymenophyllaceae ) from Southern South America

LARSEN, C.; GONZATTI, F.; ACOSTA, J. M.; PONCE, M. M.

SYSTEMATIC BOTANY

AMER SOC PLANT TAXONOMISTS

Lugar: Laramie; Año: 2020 vol. 45 p. 439 - 449

0363-6445

Morphological studies and molecular phylogenetic analyses were carried out to assess the taxonomic status of Hymenophyllum caudiculatum, a species with a disjunct distribution in South America. The species is found in tropical and subtropical forests of Brazil and in temperate forest of southern Argentina and Chile. Based on the results of morphological, molecular and species delimitation analyses, Hymenophyllum caudatum of the Valdivian forest of southern Chile and Argentina is proposed as a species separate from H. caudiculatum endemic to Brazil. The two taxa are delimited, respectively, as follows: 1?5 cm long non-alate stipes (vs. 0.3?1 cm long non-alate stipes in Brazilian H. caudiculatum); stipe wings gradually ending (vs. stipe wings abruptly ending very near the rhizome); margin entire to somewhat undulate (vs. margin undulate to crispate); soriferous segment alate, angostate or null (vs. soriferous segment with laminar constriction at apex); and widely obovoid receptacle with sessile sporangia (vs. flattened obovoid or globose receptacle with shortly pedunculated sporangia). Descriptions for the two species recognized here and a map of their geographical distribution are provided, along with nomenclatural revision, illustrations and conservation status assessments.