Ascocarps intraepidermal. In vertical section upper stromatal layer up to 18-30 µm wide, cap of dense, black tissue around opening, otherwise comprising hyaline to brown, thin walled cells, 4-9 µm diam., paler near the outer edge of the ascocarp. Lower stromatal layer 20-30 µm wide, of 2-4 layers of dark brown, thick walled cells, 4-8 µm diam. Subhymenium seated on a 45-60 µm wide layer of gelatinised hyphae which also extends up the sides of the hymenium. Excipulum present, arising from the gelatinous layer at the sides of the hymenium, elements 2-2.5 µm diam., irregularly branching, septa about 10- 15 µm apart.

Paraphyses 1.5-2 µm diam., swollen to 4-6.5 µm at the fusoid to clavate apex, extending 15-25 µm beyond asci. Asci 119-137 x 6-7.5 µm, cylindric to subclavate, apex rounded, wall slightly thickened at apex, with small central pore, non-amyloid, 8-spored. Ascospores filiform, 62-77 x 1.2-1.5(-2) µm, tapering to basal end, 0-1 septate, more or less straight when released, surrounded by gelatinous sheath.

CHARACTERISTICS IN CULTURE: Ascospores of PDD 44674 and PDD 44676 germinated on agar plates after 3 days. Growth of colony slow, 0.5-1 cm diam. after 4 weeks, 3 cm diam. after 14 weeks; aerial mycelium cottony, white, sparse; agar brownish in reverse. Remaining sterile.

ETYMOLOGY: phyllocladi; refers to host plant.

NOTES: Many of the infected phylloclades have the appearance of being dissected by numerous zone lines. These zone lines however are not narrow and black as found in other species, but are formed by a darkening of the host tissue around the separate fungal lesions, and are brown, broad, and diffuse at the edges. They appear to be formed by the host as a reaction to infection, rather than by the fungus.

C. phyllocladi is similar to C. globosus in hymenial dimensions. The two species can be distinguished by host, absence of pycnidia in C. phyllocladi, and in C. globosus lacking the gelatinised layer lining the stromatal wall of C. phyllocladi. Cultural characteristics also differ.

See also notes under C. clavatus.