A MORPHOLOGICAL ASSESSMENT OF ADIANTUM-HISPIDULUM SWARTZ AND A-PUBESCENS SCHKUHR (ADIANTACEAE, FILICALES) IN NEW-ZEALAND

Two polymorphic members of the Adiantum hispidulum Swartz complex, A. hispidulum sensu stricto and A. pubescens Schkuhr, have been criticall y studied on a morphological basis, utilising frond and hair forms, pi nnule shape and size, soral features, number of sporangia per sorus, s porangial size, annulus position and number of indurated cells, spore shape and size, rhizome and stipe paleae. Separation of the two taxa i s traditionally based on frond form (A. hispidulum being described as pinnate and A. pubescens as pedate), and indumentum characteristics (A . hispidulum having medium to short stiff hairs, A. pubescens having l ong lax hairs). This study shows that only those characters associated with the pinnule hairs can be used to consistently separate the two t axa (A. hispidulum has short (63-815 mum), stiff, often pigmented hair s with enlarged basal cells, while A. pubescens has long (251-1003 mum ), soft, pale hairs with narrow basal cells). However, even these char acters showed a high degree of variability. Adiantum pubescens is give n varietal status as A. hispidulum var pubescens.