North Island: Hokianga Co., Trounson Kauri Park, 31.v.82, coll. GS, no. 43577 (TENN); PSF, Loop Track, 10.v.83, coll. KHP & GS, no. 43826 (TENN); OSF, Kauri Reserve, 8.v.83, coll. RHP, no. 43807 (TENN); WKR, Yakas Tree Track, 12.v.83, coll. GS, no. 44078 (TENN); WKR, Yakas Tree Track, 13.v.83, coll. RHP, no. 44122 (TENN); WKR, vic. Forestry Headquarters, 30.v.82, coll. GS, no. 43576 (TENN); Upper Hutt, Kaitoke Waterworks, 22.v.82, coll. RHP, no. 43575 (holotype, PDD; isotype TENN); same data, no. 43578 (TENN). South Island: PSR, Totara Track, 21.v.82, coll. RHP, no. 43579 (TENN); FGNP, Rd to Gillespie's Beach, 9.v.82, coll. RHP, no. 43588 (TENN).

Fruiting bodies up to 50 x 6 mm, clavate, simple clubs, often sulcate or weakly and irregularly undulate over the hymenium. Stipe up to 20 x 4 mm, solid, with no mycelial pad, bright yellow at base ("light cadmium"), brighter golden yellow upward ("primuline-yellow", '"apricot-yellow"), terete to subterete. Club pale yellow to cream ("maize-yellow", "baryta-yellow", "massicot-yellow", "cream-color") on hymenium, broadly to moderately rounded apically, fleshy; hymenium appearing waxy; flesh whitish within, brighter yellow than hymenium just below hymenial surface. Odour faintly fresh to negligible; taste negligible.
Macro chemical reaction: FCL = negative
Tramal hyphae of club generative, hyaline, clamped, thin-walled, of two types; (i) 4-9 µm diam., straight, somewhat inflated, of elongate barrel-shaped cells; and (ii) 1.5-2.5 µm diam., meandering, often anastomosed in "H''-connections. Subhymenium extensive, of tortuous hyphae 1.5-2.5 µm diam. Hymenium thickening; basidia 40-80 x 8-11 µm, clavate, clamped; contents scattered-multiguttulate when mature; sterigmata 4, up to 10 µm long, stout, straight, divergent.
Spores 5.0-5.8(6.5) x 5.0-5.4 µm (E = 1.00-1.20; E^m = 1.05; L^m= 5.58 µm), globose to subglobose, hyaline, thin-walled; contents homogeneous to massively uniguttulate, the guttule refringent under phase contrast; hilar appendix abrupt, narrow, papillate.

Receptacula ad 50 x 6 mm, clavata, sulcata, flava. Hyphis et basidiis fibulatis. Sporis globosis vel subglobosis, ut in oratione infra. Hymenio in FCL non-virescenti.

As explained in the introduction to subg. Clavulinopsis, Clavaria novo-zealandica is a member of a pair of taxa which produce inflated, clavate fruit bodies, reminiscent of highly reduced agarics, rather than the usual cylindrical or narrowly fusiform fruit bodies usually associated with the genus. The other member is Clavaria sulcata. From it, C. novo-zealandica is easily distinguished by its golden yellow stipe and creamy club.
Sterigmata, as in the other similar taxa, are very stout, straight and divergent, and basidia are persistent after spore discharge. Basidial length is extremely variable, but this may be a function of their time of production and/or elongation in the thickening hymenium.
The only taxon likely to be confused with Clavaria novo-zealandica is C. luteostirpata (q.v.), but although fruit body stature and colour are similar, there is no tendency toward fruit body inflation in C. luteostirpata. Moreover, the spores of the latter are elongate, and tramal hyphae are clampless.
Dried specimens are impossible to distinguish macroscopically from other similar taxa, for all become more or less fleshy ochre and resemble diminutive fruit bodies of Clavariadelphus pistillaris Linn.: Fr. Squash mounts in 2% KOH remain unchanged in colour, or are slightly greenish yellow, whereas mounts of C. amoena turn bright golden yellow, but the two taxa are also separable on spore shape.