Hypocenomyce
Type : Hypocenomyce scalaris (Ach. ex Lilj.) M.Choisy [=Lichen scalaris Ach. ex Lilj.]
Description : Flora (1985: 188–189). See also Timdal (1984a: 93; 2002a: 223).
Hypocenomyce is a cosmopolitan genus of 13 species (Timdal 1984a, 2001) included in the family Lecideaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005), though Timdal (2001: 452) regards its familial position in the Lecanorales as still unsettled. The genus can be divided into four species groups (the H. anthracophila group, the H. friesii group, the H. scalaris group and the H. xanthococca group) on the basis of apothecial and conidial characters, type of pigment in the epithecium and pycnidial wall, and chemical properties of the thallus. Timdal (1984a: 92) lists the following characters as being important for delimiting species of Hypocenomyce from species of Lecidea sens lat.: (1) squamulose thallus, (2) black, plane, marginate apothecia, (3) weakly conglutinated paraphyses, (4) ±fusiform, partly septate ascospores, (5) sessile pycnidia, (6) lignicolous or corticolous habit, (7) a preference for burned wood as a substratum. Further, he states "... The characters delimiting Hypocenomyce against Lecidea s. lat., are partly morphological and ecological, whereas the characters which separate the groups within Hypocenomyce are mainly anatomical and chemical. It is therefore probable that the genus is polyphyletic and that some, or all, of the four groups have evolved independently from crustose lignicolous species of Lecidea s. lat. It is possible that some groups, especially the H. friesii and H. xanthococca groups, are rather closely related, whereas the H. anthracophila group appears to be only remotely related to the other groups" (Timdal 1984a: 93). Two species are recorded from New Zealand, but the genus is still poorly collected and understood here.
