Peridium depressed globose or sub-turbinate, to 3 cm. tall, 4 cm: diameter, apex bluntly rounded, base abruptly truncated, slightly excavated ; exterior at first white, in dried plants ochraceous, smooth, slightly viscid, irregularly areolate, base finely pubescent and somewhat papillate ; composed of two layers, the outer about 100 µ thick, composed of septate hyphae partly gelatinized and arranged in a vertical palisade absent from the truncate base, the inner of hyaline pseudoparenchyma to 800 µ thick, firm and compact. Stem at first white, becoming greyish or ochraceous, to 2 cm. long, 1 cm. thick, tapering, smooth, dull, hollow, attenuated abruptly at the glebal margin to a narrowly cylindrical columella 2-3 mm. thick and white. Gleba closely oppressed to the columella, ferruginous, cells lenticular, to 1 mm. long; tramal plates 30-60 µ thick, pseudoparenchymatous ; basidia 4-spored. Spores ovate-elliptical or ovate-fusiform, 10-16 x 6-8 µ (occasionally attaining a length of 20 µ), irregular in size and shape, bluntly acuminate or rounded, base bluntly pointed, apiculate, epispore pallid ferruginous, smooth, 1 µ thick.

Peridium depressum globosum vel sub-turbinatum, ad 3 cm. altum, 4 cm. diam., spice habatatum rotundatum, basi truncatum, superficie album, siccitate ochraeeum, leve, irregulariter areolatum, hyphis 2-lamellatia. Hyphae lamellae eateriorae palum densum formantes, interiorse hyaline pseudoparenchymatae. Caulis albus, siccitate griseus, apicem versus regulariter angustatus, levis, cavus. Gleba cellularis, ferrugineus, cellulis ad 1 mm. longis, lenticulatus ; laminis tramarum pseudoparenchymatis. Sporae ovato-ellipticae vel ovato-fusiformes, 10-16 x 6-8 µ, episporium pallide ferrugineum, levae 1 µ crassum.

The species is separated from S. viresens and S. erythrocephalum principally by the peculiar structure, areolated appearance, and different colour of the peridium. It is composed of two layers, the outer being so constructed of hyphae arranged in a palisade that it ruptures readily, exposing the tough pseudoparenchymatous inner layer and giving to plants their areolated appearance. Spores resemble those of S. erythrocephalum in shape.

Distribution : Auckland, Swanson, Miss J. Dingley, type collection.