Circumscription of the South American Moonwort Botrychium dusenii (Ophioglossaceae)

ESTEBAN MEZA TORRES; STENSVOLD, MARY; FARRAR, DONALD .R; MARÍA S. FERRUCCI

PLANT BIOSYSTEMS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2017 vol. 151 p. 258 - 268

1126-3504

The genus Botrychium (Ophioglossaceae) is comprised of about 30 widely distributed species. Because of their small size and few, yet variable, morphological characters, many questionable taxa have been described over the years. Since its description in 1906, B. dusenii has been treated as both a distinct species and as a variety of B. lunaria. It has also been variously divided into four taxa: B. lunaria var. dusenii, B. lunaria var. antarctica, B. ramosum var. patagonicum, and B. matricariifolium ssp. patagonica. The aims of this study are to evaluate validity of these taxa using characters of morphology, spore wall sculpture and size, and allelic composition using enzyme electrophoresis. We conclude that only one species of Botrychium occurs in the study area and recognize this as B. dusenii, a species distinct from B. lunaria. Enzyme electrophoresis and spore size suggest that B. dusenii is an allotetraploid derived through hybridization between a diploid member of B. lunaria complex and a diploid member of the B. campestre complex. We provide information about habitat, distribution, and full exsiccate citations.