Apr 2, 1999 - Hymenium 80-100 um thick, diffuse yellow-brown in the upper part, elsewhere colourless, heavily gelatinized with the gel IKI+pale blue without ...
Lichenologist 31(6): 555-558 (1999) Article No. lich. 1999.0209 Available online at http://www.idealibrary.com on IDEKL
STEINIA AUSTRALIS, A NEW SPECIES IN THE LICHEN FAMILY APHANOPSIDACEAE G. KANTVILAS* and P. M. McCARTHYJ Abstract: Steinia australis Kantvilas & P. M. McCarthy is described, based on a specimen from Tasmania. The new species, the second in the genus and only the third in the family Aphanopsidaceae, differs from 5. geophana by its larger ascospores, well-developed exciple and scurfy, leprose thallus. £) 1999 The British Lichen Society
Introduction The lichen family Aphanopsidaceae was described recently by Printzen & Rambold (1995) to accommodate two unusual monospecific genera, Aphanopsis Nyl. ex Sydow and Steinia Korb. It is characterized by a crustose thallus with a green, coccal photobiont, apothecial ascomata, 8- or 16-spored asci with non-amyloid walls and a tholus with an amyloid plug, and by simple, colourless ascospores. Accounts of Aphanopsis and Steinia are provided by Coppins & James (1984) and Purvis (1992a), and by Purvis (19926), respectively. Both occur mainly on soil and stones in rather disturbed habitats such as along roadsides, and are considered transient and short-lived (Poelt & Vezda 1990). In this paper we describe a second species of Steinia, recently discovered in Tasmania. This remarkable lichen represents the first record for the Southern Hemisphere of an otherwise temperate, Northern Hemisphere family. Materials and Methods Observations and measurements are based on hand-cut sections mounted in water, Lugols iodine, 50% HNO3, 10% KOH, toluidine blue and ammoniacal erythrosin, and examined using standard light microscope techniques. Ranges of anatomical measurements are derived from ten apothecia sectioned and 100 ascospores.
Comparative material examined: Aphanopsis coenosa (Ach.) Coppins & P. James: Austria, Styria, Gleinalpe, Oswaldgraben prope Kainach, 850 m, 7 v 1989, J. Poelt & H. Pittoni (A. Vezda, Lich. Sel. Exs. 2347) (HO). Steinia geophana (Nyl.) B. Stein: Denmark, Zealand, Allerod, Nymollevej, 55°52'N, 12°22'E, 29 xi 1986, Th. Laessee & V. Alstrup (H. Hertel, Lecideaceae Exs. 177) (CANB); Czech Republic, Bohemia centralis, distr. Beroun, 420 m altitude, 13 ix 1989, J. Hordkovd (A. Vezda, Lich. Rariores Exs. 228) (CANB, HO); Austria, Burgenland, Lehmgrube und Mischwald SE DeutschBieling, nahe der Grenze, 200 m altitude, 5 iii 1989, J. Poelt & H. Pittoni (HO). *Tasmanian Herbarium, G.P.O. Box 252-04, Hobart, Tasmania 7001, Australia. ^Australian Biological Resources Study, G.P.O. Box 636, Canberra, A.C.T. 2601, Australia. 0024-2829/99/060555 + 04 $30-00/0
© 1999 The British Lichen Society
556
THE LICHENOLOGIST
Vol. 31
^
FIG. 1. Steinia austmlis habit, showing ascomata at various stages of development. Scale: 0-5 mm.
Steinia australis Kantvilas & P. M. McCarthy sp. nov. Species Steiniae geophanae similis sed ascosporis magnioribus, 8-12 urn longis et 7-11 um latis, excipulo cupulato, bene evoluto, et thallo furfuraceo-leproso differt. Typus: Australia, Tasmania, Native Plains Road, c. 4 km SW of Sassafras, 41°19'S, 146°28'E, on soil in ± dry underhang along roadside at edge of eucalypt forest and pasture, 70 m altitude, 7 October 1998, G. Kantvilas 193/98 (HO—holotypus).
(Figs 1-2) Thallus scurfy, leprose, pale green to greyish green, thin, rather patchy, not delimited; photobiont cells ± globose, 12-20 um diam. Apothecia black to brown-black, matt, scattered, solitary, superficial or embedded slightly in the substratum, 0-2-0-35 mm diam., up to c. 0-25 mm tall; margin not distinct; disc uneven, minutely roughened, plane at first, soon becoming strongly convex, at length eroding and leaving only the excavate, black, dish-like exciple. Exciple well developed, cupular, opaque black-brown, pigment unchanged in KOH and HNO 3 , 60-80 um thick beneath the hymenium, thinner and becoming excluded laterally. Hypothecium 70-90 um thick, pale yellow-brown to colourless. Hymenium 80-100 um thick, diffuse yellow-brown in the upper part, elsewhere colourless, heavily gelatinized with the gel IKI+pale blue without pretreatment in KOH; asci narrowly cylindrical, 80-100 x 14-20 um, with non-amyloid, 0-5-1 um thick wall and tholus with an amyloid plug or cap; paraphyses simple, flexuose and somewhat tangled, 0-5-1 um thick, typically shorter than the asci; septa indistinct. Ascospores globose or almost so, frequently rather deformed and angular when in the ascus, 8-12 x 7-11 um, typically with a large, central vacuole; wall 0-5-1 um. Pycnidia not seen.
1999
Steinia australis—Kantvilas & McCarthy
557
FIG. 2. Steinia australis: A, mature ascus and paraphyses, with amyloid parts stippled; B, immature ascus; C, ascospores; D, section through apothecium, showing heavily pigmented exciple and mature asci protruding out of a gelatinized hymenium. Scales: A-C= 10 urn; D= 100 urn.
Notes. The gross morphology of the new lichen, and its characteristic Aphanopsis-Xype (sensu Printzen & Rambold 1995) asci containing 16 hyaline, ± globose ascospores closely ally it to the widespread Northern Hemisphere species, S. geophana. It differs most notably by the prominent, leprose thallus and the disjunctly larger ascospores; in S1. geophana the thallus is rather film-like and inconspicuous and the ascospores are only 5-7 (am diam. Also noteworthy is the well-developed exciple, a character not found in either 5. geophana, where the exciple is reduced to a thin (c. 10 (am) layer of pigmented hyphae, or in Aphanopsis. In 5. australis, the exciple is a prominent, cupular structure, cradling the hymenium and hypothecium. It is typically continuous, although in some apothecia it is open in the centre (Fig. 2). In older apothecia, this tissue becomes rather excluded at the sides, but remains intact beneath the apothecia. Eventually, the hymenium becomes completely eroded but the blackish excipulum remains, rather like old excavate perithecia in some pyrenocarpous lichens (Fig. 1). The hymenium is heavily gelatinized, and mature asci typically protrude through the surface of the disc, making it uneven and lumpy. The amyloid plug or cap is evident in young asci, but is rapidly compressed and is visible sometimes only as a thin darker staining area
558
THE LICHENOLOGIST
Vol. 31
between the ascus wall and the ascus contents. In that respect, the new species appears to differ somewhat from S. geophana, where the amyloid structure is more obviously plug-like and more persistent as the asci mature. In both species, the paraphyses are often markedly shorter than the asci. Steinia australis is known only from the type locality where it was growing on relatively freshly disturbed, unconsolidated basaltic soil along a roadside at the boundary of open eucalypt forest and pasture. It formed an extensive patch of about 100 cm2, in a slightly overhanging, drier portion of a road cutting. The habitat of the new species is very similar to that of 5. geophana, which inhabits soil, stones and other substrata in similar, rather disturbed habitats (Purvis 19926). Although anatomically 5. australis is unique in the Tasmanian flora and cannot possibly be confused with any other lichens, there are several other, superficially similar taxa that inhabit soil in the same types of habitats. These lichens include some as yet unidentified species of Micarea and an unidentified member of the Lecidea hypnorum group. In addition, there is a species on soil at the margins of wet forests that superficially resembles Aphanopsis coenosa: it has a granular, goniocyst-type thallus, immarginate apothecia but with Trapeliopsis-type asci and small, hyaline simple spores, 12-14 x 6-8 urn. REFERENCES
Coppins, B. J. & James, P. W. (1984) New or interesting British lichens V. Lichenologist 16: 241-264. Poelt, J. & Vezda, A. (1990) Uber kurzlebige Flechten- (On shortliving lichens). Bibliotheca Lichenologica 38: 377-394. Printzen, C. & Rambold, G. (1995) Aphanopsidaceae- a new family of lichenized Ascomycetes. Lichenologist 27: 99-103. Purvis, O. W. (1992a) Aphanopsis Nyl. ex Sydow (1887). In The Lichen Flora of Great Britain and Ireland (O. W. Purvis, B.J. Coppins, D. L. Hawksworth, P.W.James & D. M. Moore, eds): 73. London: Natural History Museum Publications. Purvis, O. W. (19926) Steinia Korber (1873). In The Lichen Flora of Great Britain and Ireland (O. W. Purvis, B. J. Coppins, D. L. Hawksworth, P. W. James & D. M. Moore, eds): 575-576. London: Natural History Museum Publications. Accepted for publication 2 April 1999
