South America: COLOMBIA: Dpto. Antioquia, Medellin Pto.-Valdivia Rd., on unidentified fern, K. P. Dumont, S. E. Carpenter, M. A. Sherwood, 12.VIII.1976 (holotype - NY).

Ascocarps subepidermal. In vertical section upper stromatal layer poorly developed, 20-25 µm wide, not becoming wider around opening, composed of brown to very pale brown, thick walled, angular to globose cells, 3-6 µm diam. Inside of stromatal layer lined with periphyses when immature. Excipulum becoming well-developed as ascocarps mature, arising from inner layers of upper stroma, comprising hyaline, closely septate hyphae, which become swollen, and embedded in dark brown material at apices. Lower stromatal layer 5-15 µm wide, the outer 1-2 layers of cells dark brown and thick walled, with hyaline, globose cells to the inside.

Paraphyses 1-1.5 µm diam., branching several times near apices not or only slightly swollen. intermixed with crystals, extending 15-20 µm beyond asci. Asci cylindric to subclavate, (132-)150-195(-210) x 7.5-11 µm, tapering to an acute apex, wall not thickened at apex, non-amyloid, 8-spored. Ascospores filiform, (95-)110-125 x 1.8-2.5 µm, tapering slightly to both ends, 0-1 septate, often coiling when released, surrounded by poorly developed gelatinous sheath.

Pycnidia subepidermal. In vertical section lenticular in shape, wall 5-10 µm wide, of brown, angular cells, lined with hyaline, thin walled cells on which the conidiogenous layer is held. The lower wall is wider and darker than the upper. Conidiogenous cells lining both upper and lower walls, comprising flask-shaped, sympodial, solitary conidiogenous cells, often with two conidia held at the ends. Conidia short-cylindric, 3.5-5.5 x 1 µm, hyaline, non-septate.

The ascocarps of the type specimen of C. crystalligerus are larger, have a rounder, more regular-shaped opening, and better developed layer of crystals on the hymenium, compared with New Zealand collections. Pycnidia are not present on the type specimen, but were found on some, but not all, of the New Zealand collections. Otherwise the New Zealand collections of this fungus fit the description of the type specimen well, especially with regard to the host, the appearance and size of the hymenial elements, and the structure of the ascocarp margin.

The only other rhytismataceous taxon so far consistently found on ferns in New Zealand is a Hypoderma-like species on Gleichenia cunninghamii Heward ex Hook. C. radiatus was found once on Dicksonia squarrosa