Flora of New Zealand Series

tuber sword-fern

Rhizomes small, erect, densely scaly, producing numerous far-creeping runners; runners scaly and usually bearing fleshy tubers. Stipes 5-25 cm long. Stipes and rachises pale brown, brittle, bearing pale brown hair-like scales. Laminae very narrowly elliptic, 40-100 × (4)-5-8 cm, pinnate, erect. Primary pinnae in > 50 pairs, overlapping in middle of frond, more widely spaced at base, the longest 2-4 × 0.4-1 cm, ± glabrous, oblong or narrowly oblong with a basal acroscopic lobe; apices obtuse; margins markedly crenate or serrate. Sori round, in single rows either side of midrib, protected by crescent-shaped indusia.

N.: sporadic lowland sites from N. Auckland to Waikato and Bay of Plenty, occasional further S.

Pantropic 1974

Banks, rock outcrops, track margins.

This is a commonly cultivated plant which frequently escapes in warmer parts of N.Z. It is part of a widespread polymorphic aggregate which, despite some detailed notes from Pichi Sermolli, R. E. G., Estrato Dagli Annali del Museo Civico di Storia Naturale di Genova 77 : 270-277 (1968), is still not clearly resolved into constituent elements. The naturalised plant in N.Z. differs from the native one, which has previously been known by the same name, by the presence of tubers on the stolons, and by the larger, more deeply incised pinnae (Fig. 2).