Flora of New Zealand Series

Polypodium punctatum Thunb. Fl. jap. 1784, 337.

H. petrieana Carse in T.N.Z.I. 50, 1918, 64.

Rhizome slender to rather stout, 2-4 mm. diam., creeping, densely clad in ferruginous hairs; stipites distributed. Stipes 10-15 × 2-3 cm., rather rigid, yellowish, shining, except towards darker base, glab. but ± tuberculate. Rhachis pale, ± hairy and muricate. Lamina broadly deltoid-ovate, subcoriac., 2-pinnate, 30-40 × 20-25 cm.; pinnae alt. to subopp., diverging at wide angle to rhachis, often arcuate. Primary pinnae up to 15 × 8 cm., distant, narrow-ovate, acuminate. Secondary pinnae in subopp. pairs up to 4 × 1 cm., narrow-ovate to oblong, subacute to obtuse; pinnatisect to nearly pinnate. Segs up to 5 × 2 mm., oblong, obtuse, entire or obtusely toothed. Sori 1-4 per seg., hardly or not at all protected, 1-1·5 mm. diam.

DIST.: N. Lowland from lat. 35º to lat. 38º 30'.

HYBRIDISM

A series of forms may be collected linking up the spp. as at present delimited. Part of the polymorphy found appears due to the occurrence of microspecies, part to modifications induced by habitat conditions, e.g. in the degree of development of hairs. There is good field evidence that hybridism plays a prominent part. Carse (T.N.Z.I. 60, 1930, 305), who had long studied northern forms, listed the following groups: distans × millefolium : distans × rugosula; punctata × rugosula; punctata × tenuifolia; rugosula × tenuifolia. Forms suggestive of the origin millefolium × rugosula have also been met with.

Whether the N.Z. plant is really conspecific with P. punctatum Thunb. remains uncertain. The original localities of H. petrieana Carse are given as: "Vicinity of Otorohanga, Waipa County, and Port Charles, Coromandel County. D. Petrie." Type: CM 124/5. H. punctata (Thunb.) Mett. Otorohanga, S. Auckd. Dec. 1917, D. Petrie. No Carse specimen in CM now bears the name H. petrieana.