Flora of New Zealand Series

Holotype: New Zealand. North I., South Auckland, Otupae Ra., NW Ruahine, western slopes, c. 1100 m, on greywacke outcrops, 39º32's, 176º11'E, 11.xi.1983, J.K. Bartlett 27927a – AK. Isotype – BM.

Description : Thallus fruticulose, mat-forming, of small, crowded, erect to straggling, fragile, terete ramuli, dying at base. Ramuli simple, occasionally sparingly branched, (80–)100–140(–190) μm diam., 5–8(–10) mm tall, pale olive greenish, yellow-brown to red-brown at apices, dark red-brown to black in older parts and at base; in young, apical parts ramuli ±translucent when wet, with colonies of green photobiont clearly visible as minute maculae (×10 lens), surface matt to somewhat shining, without isidia, pseudocyphellae or soredia. Apothecia and pycnidia not seen. Anatomy : Comprising two kinds of hyphal arrangement, an outer paraplectenchymatous zone 10–35 μm thick, of thin-walled, round to somewhat irregular ±isodiametric cells 4.5–7 μm diam., outermost cells pigmented red-brown and forming a thin cortical layer often intermixed with photobiont cells, internally becoming paler to ±hyaline. Photobiont cells round to somewhat irregular, 4.5–7(–9) μm diam., chloroplast filling whole cell, clustered in groups (4–12) in a zone extending from outer surface of ramuli to central medullary strand, sometimes associated with outer paraplectenchymatous cells in forming an external cortical layer. Medulla of periclinally arranged septate hyphae in a central, fragile cord, 40–70 μm thick, cells 3–5 m diam, colourless to pale yellow-brown or dark red-brown in older parts, unchanged in K.

Chemistry : Thallus K−, C+ rose-red, KC+ rose-red, Pd−; containing gyrophoric acid.

N: Gisborne (Mt Hikurangi), Hawke's Bay (Kaweka Ra.) to Wellington (Tongariro National Park, Northern Ruahine Ra.). S: Otago (St Marys Ra., St Bathans Ra., Pisa Ra., Old Woman Ra., Old Man Ra.). In fellfield turf-moss communities on mountain summits, 1000–1840 m. Associating with species of Cladonia, Frutidella caesioatra, Hypogymnia lugubris, Lepraria neglecta, Pseudephebe pubescens, Stereocaulon caespitosum, S. colensoi, Umbilicaria cylindrica, U. hyberborea, U. vellea, Usnea subcapillaris, U. torulosa and the bryophytes Cephaloziella, Grimmia and Racomitrium. Still very poorly collected in high-alpine habitats. Known also from the Falkland Is (Alan Fryday pers. comm.).

Austral

Illustrations : Galloway & Jørgensen (1990: 6, figs 1, 2; 7, figs 3, 4; 9, fig. 6B, C).

All specimens of Bartletiella seen have a ±constant morphology with all specimens being extremely brittle and easily fragmented. Bartlettiella is reminiscent of certain fruticulose cyanobacterial genera such as Polychidium or Spilonema rather than any known lichen with Trebouxia as photobiont. However, there is no evidence that it is a photosymbiodeme since its structure is distinctively different from such cyanobacterial fruticulose genera whose morphology is largely determined by the arrangement of the cyanobacterial photobiont. Bartlettiella is distinguished from Pseudephebe pubescens both in anatomical and chemical characters (Galloway & Jørgensen 1990: 7).