Micarea flagellispora
Description : Thallus effuse, of scattered to usually confluent areolae, often with a blackish prothallus forming a background to areolae. Areolae (80–)100–400 μm diam., convex to ±globose, whitish, greenish white, sometimes with a dull-yellowish tinge, usually rather bright green when fresh, sometimes upper parts of areolae tinged grey (because of cortical pigment) or dicoloured brown, matt; cortex or necral layer to 8 μm thick, hyaline or pale- to dark-green, K−, N+ red. Prothallus of dark-green hyphae (rarely purplish), N+ red, 2–3.5 μm wide. Photobiont cells micareoid, 4–7 μm diam. Cephalodia present, occasionally visible externally and resembling dark-brown areolae, but mostly buried beneath areolae or apothecia, c. 100–300 μm diam., containing disrupted filaments of Scytonema with cells 7–13 μm wide. Apothecia numerous, (0.1–)0.3–1 mm diam., scattered to confluent, at first plane and weakly marginate, later becoming immarginate and convex–hemispherical, black or rarely brown-black, matt. Hymenium 65–85 μm high, pale greenish slate-grey (K+ green intensifying), but commonly appearing darker because of dense vertical streaks of slate-black pigment (K+ green-black) coating sides of asci and paraphyses; occasionally greenish pigment is replaced wholly or in lower hymenium by purplish pigments (K+ green or K+ purple intensifying). Paraphyses numerous, branched, rather coherent in K when heavily pigmented, (1–)1.5–2 μm wide, apices swollen to 2.5 μm. Hypothecium 170–360 μm thick, blackish green (K+ green intensifying) or partly (rarely completely) purplish brown-black (K+ green or partly or completely K+ purple intensifying). Exciple well-developed, concolorous with hypothecium, of radiating branched hyphae, 1.5–2.5(–3.5) μm wide, rather coherent in K. Asci cylindrical, 63–83 × 9–12 μm, ascospores spirally arranged, in K/I with an outer amyloid layer and an amyloid apical dome, which is penetrated by a shallowly conical ocular chamber and a narrow apical cushion that ± reaches the upper wall. Ascospores narrowly acicular, sigmoid or flexuous, indistinctly 3–7-septate, 60–85 × 1.5–1.7 μm. Pycnidia rare, immersed in areolae to ±sessile, 80–200 μm diam., black, ±globose, ostiole eventually gaping; wall dark-greenish or in part purplish (K+ green). Macroconidia filiform, flexuous, simple, 60–77 × 1 μm.
Chemistry : Thallus K−, C−, KC−, Pd−; containing perlatolic acid.
S: Canterbury (Lewis Pass). On soil, litter, rotting wood and at bases of low shrubs in subalpine habitats. Known also from Tasmania (Coppins & Kantvilas 1990: 284; McCarthy 2003c, 2006).
Australasian
Illustrations : Coppins & Kantvilas (1990: 282, fig. 3).
Micarea flagellispora is characterised by: the terricolous habit; the effuse, whitish, green-white to dull-yellowish areolate thallus; the scattered to confluent, black or brown-black, convex apothecia; the 3–7-septate, acicular, sigmoid or flexuous ascospores, 60–85 × 1.5–1.7 μm; and the filiform, flexuous conidia, 60–77 × 1 μm.
