Flora of New Zealand Series

Polypodium pumilum (J. B. Armst.) Ckn. Rep. Bot. Surv. St. Id 1909, 47.

P. billardieri var. pumilum (J. B. Armst.) Cheesem. Man. N.Z. Fl. 1906, 1010.

Type locality: Armstrong merely gives "Canterbury and Otago Provincial Districts". Endemic.

Rhizome creeping, slender, branching, often densely arranged, the plant forming matted patches, up to 10 cm. long; clad when young in pale brown ovate to ovate-lanceolate to spathulate paleae up to 5 mm. long; fronds close-set along rhizome in about 3 series. Stipes hardly developed. Lamina coriac. to almost fleshy, dark green; spathulate to oblong- or linear-spathulate, gradually narrowed to base; glab. when old, ± pubescent below, and sts above, when young; veins hidden, sts the main vein evident; 5-12 × 3-5 mm.; rarely up to 3 cm. long; margins entire to faintly sinuate. Sporangia us. aggregated in a mass near apex of frond, 2-3 mm. diam., rarely as a pair of coenosori || and close to main vein and up to 1 cm. long; paraphyses few or absent.

DIST.: N., S., St., A., C. From about lat. 38° southwards; subalpine, but descending to montane areas and lowland in southern part of range; apparently rather rare in N.

Kirk (T.N.Z.I. 17, 1885, 232) described his Polypodium crassum (so spelt on type sheet, misspelt crassium when published) from "bare rocks on the highest peaks of Mount Anglem, 3,000 feet." The fronds are 4-12 mm. long, spathulate to narrow-spathulate or obovate (not as described by Kirk) narrowed to stipe-like base; paleae acute. Type: W, No. 204 (Kirk 1057).

POLYMORPHY

Intergrading forms from G. crassa to G. pumila are not uncommon; how far these are due to the influence of the habitat and altitude has not been determined, but the species appear to be at least to some extent plastic. G. pumila, at least, would repay cultural studies. A plant collected by Zotov at 1400 m. alt. on Mount Crawford, Tararua Range (BD 4388) has a creeping rhizome with ovate-lanceolate paleae; stipites up to 5 cm. long, laminae up to 4 × 1 cm.; ovate-oblong to spathulate, obtuse.