Is the enigma a variation? Sagina boydii F. B. White (Caryophyllaceae), Boyd's pearlwort

Abstract

Sagina boydii F. B. White (Caryophyllaceae), Boyd's pearlwort, is an enigmatic taxon of unknown geographical origin which is only known in cultivation and is of uncertain taxonomic status. Morphological, cytological and geographical evidence suggests that it is most similar to S. procumbens L. and S. saginoides (L.) H. Karst., but it differs in its compact growth form. Genetically, AFLP analysis shows that it can be included as part of the variation in S. procumbens. In cultivation, it will grow true from seed. Other compact growth forms occur in S. procumbens but do not grow true from seed. As S. boydii is part of the variation in S. procumbens, is of uncertain geographical origin, is known only in cultivation, and grows true from seed, it is best treated as a new cultivar, Sagina procumbens 'Boydii'. A neotype and standard specimen is designated. © 2005 The Linnean Society of London.