Flora of New Zealand Series

Thallus crustose, thin, effuse, granular, powdery or continuous, ± coriaceous, matt or shining, whitish or pale glaucous grey to olivaceous, sometimes white-arachnoid towards margins, spreading in irregular patches or ± orbicular, corticolous. Photobiont green, Trebouxioid. Apothecia immersed to sessile, ± urceolate, rounded to irregular, lecanorine, disc concave to plane, pale yellowish-brown to red-brown or blackened, with or without a whitish pruina, margins entire, or split and fractured and somewhat gyalectiform, with or without farinose soredia. Hymenium 130-200(-250) µm tall, colourless. Epithecium granular, brown-black. Paraphyses slender, septate, densely conglutinate, anastomosing, apices swollen, suffused yellowish-brown. Hypothecium colourless or straw-yellow to dark brown. Ascospores (1-)4-8 per ascus, fusiform, and slightly curved to oblong-ellipsoid, colourless, 3-13(-23)-septate, cells lenticular.

Phlyctella is a genus of corticolous lichens containing c. 9 species found in India, Australia, South America and New Zealand. It was first described by Krempelhuber [ Verhandl. zool.-bot. Ges. Wien 26: 452-453 (1876)] to accommodate two New Zealand taxa and is included in the family Lecanoraceae although the exact relationships of the genus are not yet certain. Six species are here recorded from New Zealand although the genus is still much in need of collection and study and at least one undescribed species is known. All species are thin in texture and spread over bark, forming whitish or pale greenish-grey patches like daubs of white paint on smooth-barked trees and shrubs in moderate to dense shade. The shape of the thallus surface is much influenced by the configuration and texture of the surface on which the lichen is epiphytic. All species have a well-defined chemistry producing one or more of the following depsidones; stictic, constictic, norstictic and hypostictic acids and also psoromic and fumarprotocetraric acids. Species now included in Phlyctella were first described as Platygrapha [Nylander J. Linn. Soc. Lond. Bot. 9: 258 (1866)] and as Phlyctis [Stirton J. Linn. Soc. Lond. Bot. 14: 464 (1875)]; Knight T.N.Z.I. 7: 356 (1875); Trans. Linn. Soc. Lond. ser. 2, Bot. 1: 281 (1878); T.N.Z.I. 15: 349-350 (1883)]. Five species appear to be endemic.