Chaenothecopsis Vain.

Lichens A-Pac (2007) - Flora of New Zealand Lichens - Revised Second Edition A-Pac

CHAENOTHECOPSIS Vain., 1927

Type : Chaenothecopsis rubescens Vain.

Description : Saprobic or parasitic, lichenised thallus lacking. Ascomata apothecia, stalked or sessile, black to brownish black or with a paler stalk. Capitulum obovoid to lenticular. Mazedium not developed. Exciple ±well-developed, of dark-brown, periclinally arranged hyphae. Hymenium covered by a thin dark epithecium. Stalk formed of pale, intricately woven or of periclinally arranged, dark-brown hyphae. Asci formed singly from ascogenous hyphae with croziers, cylindrical to subclavate, 25–55 μm long, persisting until ascospores mature; apex strongly thickened and penetrated by a very fine canal or, in some species, with a short and wide canal or uniformly thickened and with no canal. Ascospores uniseriate, simple or 1-septate, dark-brown to pale-brown or with an aeruginose cast, ellipsoidal to dusiform; wall of medium thickness, smooth or minutely verrucose.

Key

Ascospores simple

Ascospores 1-septate

Stalk dark-red in incident light, especially below capitulum

Stalk dark-brown to black in incident light, or paler towards base

Apothecia large, 0.8–3.1 mm tall, stalk red or dark throughout; ascospores smooth or very minutely ornamented

haematopus

Apothecia smaller, 0.5–0.8 mm tall; stalk red in uppermost part or brownish, usually paler towards base; ascospores distinctly ornamented

nivea

Capitulum K−

Capitulum K+ green (squash preparation)

nivea

Ascospores with rounded ends, pale-brown or pale greenish, periclinallly arranged and not densely packed in ascus

Ascospores allantoid, dark-brown, densely and obliquely packed in ascus

nana

Lignicolous, often parasymbiontic or parasitic on species of Chaenotheca

savonica

On exudate on bark of living Schefflera

schefflerae

Stalk and/or exciple K+ strongly red or greenish (sometimes fugitive)

Stalk and/or exciple K− or slightly reddish or greenish brown

Stalk and exciple K+red (fading fast)

* lignicola

Stalk and exciple K+ green

viridireagens

Stalk in section (squash) red

Stalk in section brownish, greenish or pale

Stalk in section yellowish red, unchanged in H

sanguinea

Stalk in section pale violet, H+ grey-violet intensifying

debilis

Stalk short, 1–2 times as long as width of capitulum or shorter

Stalk 2–5 times as long as width of capitulum

Exciple red, largely of isodiametric cells; parasitic on Arthonia

* brevipes

Exciple brown, of elongated hyphae; parasitic on Sagenidium

* sagenidii

Ascospores with septum more heavily pigmented than wall

Ascospores with thin and poorly pigmented septum

Central part of stalk hyaline, of swollen, interwoven hyphae; ascospores 5.5–7 × 2–2.5 mm

* tasmanica

Central part of stalk with periclinally, thin hyphae; ascospores 4.5–5.5 × 1.5–2 μm

nigra

Stalk straight, of interwoven hyphae, strongly swelling in K (no colour reaction); ascospores 6–7 μm long, smooth

pusilla

Stalk flexuous, of thin, periclinally arranged hyphae, K+ yellow (dissolving), not swelling; ascospores 7–9.8 μm long, wrinkled longitudinally

nigropedata

Chaenothecopsis is a cosmopolitan genus of cool temperate to temperate regions, having some 56 described species (Tibell & Ryan 2004h), accommodated in the family Mycocaliciaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005). Species occur as saprobes, parasymbionts or parasites on various lichens, bark and lignum, with a few species occurring on rocks in shaded habitats. Many species are found on other calicioid lichens especially on species of Calicium and Chaenotheca. Other species grow as parasites on free-living algae or on the exudates of vascular plants. Fifteen species are known from New Zealand (Tibell 1987). For detailed information on the genus worldwide see Tibell (1982, 1984b, 1987, 1991, 1994, 1998a, 1999c), Tibell & Thor (2003), Tibell & Ryan (2004h) and Titov et al. (2004).

Chaenothecopsis Vain.

Key

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