Flora of New Zealand Series

Coenopteris flaccida Thunb. Nov. Act. Pet. 9, 1795, 158, t. D, f.l, 2.

C. novae-zelandiae Spreng. in Schrad. J. Bot. (1799) 2, 1799, 269.

Darea flaccida Willd., and

D. odontites Willd. Sp. Pl. 5, 1810, 245.

A. heterophyllum A. Rich. Essai Fl. N.Z. 1832, 74.

Rhizome short, stout, erect to shortly creeping, clad in brown linear-attenuate paleae c. 1 cm. long; stipites tufted to approximate, paleate at base, and with a few weaker paleae elsewhere when young. Rhachis winged, bearing scattered paleae. Laminae and pinnae diverse in size and shape, us. thick, long-pend. to short-erect; veins obscure, us. a single veinlet to each seg., sori oblong, us. submarginal; indusium pale, firm.

DIST.: K., N., S., St., Ch., A. Common in lowland to montane forests throughout; also, in distinct forms, coastal. Also in Australia, Tasmania, Pacific Islands, and reported from S. Africa.

Forster's description is: "frondibus pinnatis: foliolis alternis remotis pinnatifidis, segmentis linearibus strictis". The status of the numerous forms at present included under the name A. flaccidum remains uncertain. Hooker (Fl. N.Z. 2, 1855, 36) described, without naming or giving localities, 4 vars: "it would take many pages to enumerate half its protean forms". A rough grouping is here attempted - there are many linking forms:

1. Lamina pinnate, without secondary pinnae

(a) Pinnae pinnatifid, segs of oblong-triangular order

(i) Fronds pend.; plant epiphytic

Example: BD 72472, Wilton's Bush, Wellington. Lamina c. 30-40 cm. long, oblong-lanceolate, acuminate; pinnae distant, alt.; larger up to 12 × 1 cm., linear-lanceolate; barren sinuate-crenate; fertile pinnatifid, segs oblong-triangular, acute; sori near sinus, 2-4 mm. long, never confluent. Plants of this form are widespread.

(ii) Fronds erect or ascending; plant rupestral

Example: BD 2233, Titahi Bay, Wellington. Lamina c. 10-15 cm. long, narrow-ovate, acute to acuminate; pinnae approximate, alt. to subopp.; larger up to 3 × 1 cm., ovate-oblong; barren similar to fertile, pinnatifid; segs obovate-oblong to oblong-triangular, up to 5 mm. long; sori submarginal, up to 5 mm. long, often confluent. A form of coastal rocks.

(b) Pinnae pinnatisect; segs of linear order; plant epiphytic

Example: BD 76095, Hall's Arm, Doubtful Sound. Lamina c. 30-60 cm. long, lanceolate in outline; pinnae alt., distant; larger up to 15 × 2 cm., linear-lanceolate, attenuate; barren similar to fertile; segs linear, up to 2 cm. long; sori up to 10 mm. long, not reaching to sinus. Common form of southern fiords, may equal Forster's type.

2. Lamina pinnate, pinnae with single secondary basal pinnae; epiphytic

(a) Segs oblong, not over 1 cm. long

Example: BD 44654, Shag Creek, Little Barrier Island. Lamina c. 35 cm. long, ovate-oblong, acuminate, pend.; pinnae alt., distant, up to 8 × 3 cm., lanceolate, acuminate; barren pinnatifid, fertile pinnatisect; accessory pinna up to 4 cm. long, acuminate; sori up to 5 mm. long. A fairly widspread form.

(b) Segs linear, up to 25 mm. long

Example: BD 71264, Stillwater River, Caswell Sound. Lamina c. 50 cm. long, ovate-oblong, acuminate, pend.; pinnae alt., distant, linear-lanceolate, acuminate; barren similar to fertile; larger up to 25 × 6 cm., narrow-lanceolate, pinnatisect; segs distant; sori up to 10 cm. or more long; accessory pinna up to 20 cm. long. Known from southern fiords.

3. Lamina bipinnate

(a) Pinnae with a few basal secondary pinnae

Example: BD 8651, Noixette Islands, Hauraki Gulf. Plant rupestral, fronds ascending; lamina c. 20-25 cm. long, about ovate in outline; primary pinnae up to 8 × 3 cm., pinnatisect, barren and fertile similar; secondary pinnae few, up to 3 cm. long, pinnatisect; segs linear-oblong; sori up to 5 mm. long. A common coastal form of northern islets. Forms approaching that described by Dobbie (N.Z. Ferns 1951, p. 357) from Karewha Island, Bay of Plenty, occur. The Karewha form is tripinnate, with linear segs. The plant forms large clumps with fronds up to 60 × 15 cm., upright to spreading.

(b) Pinnae with numerous secondary pinnae

Example: BD 3919 Chatham Islands. Lamina c. 20-35 cm. long, ovate-oblong; pinnae distant, alt., barren and fertile similar, up to 12 × 6 cm., ovate-oblong, acute to acuminate; secondary pinnae alt., distant, up to 5 × 1·5 cm., ovate-lanceolate, acute to acuminate, pinnatisect: segs up to 1 cm. long; sori oblong, up to 5 mm. long. May be a hybrid bulbiferum × flaccidum.