Two Decades Later: A Bibliographic Revision of Menegazzia in Chile with New Identification Key and Phylogenetic Perspectives

Abstract

This study presents a bibliographic review of the genus Menegazzia in Chile, the first in over two decades, updating new records, the taxonomic placement of the genus, and the synonymization of species. Up to twenty species have been cited in the country, considering that M. albida, M. hollermayeri, and M. norstictca are synonyms of the valid species M. wilsonii, M. dispora, and M sanguinascens. A fully revised dichotomous key and color photographs are included to facilitate accurate identification, especially given the genus’s morphological convergence and sparse reproductive structures. For the first time, the divergence times of Menegazzia lineages are discussed in relation to major Southern Hemisphere geologic events, suggesting a dispersal-driven distribution with a crown age of approximately 21.2 Ma. This review consolidates fragmented data, integrates recent molecular findings, and emphasizes the genus’s value as an ecological and biogeographic indicator in Chilean temperate forests.

1. State of the Art

1.1. Menegazzia Genus

The genus Menegazzia A. Massal. was established by the Italian lichenologist Abramo Bartolommeo Massalongo in 1854, designating M. terebrata (Hoffm.) A. Massal as the type species [1]. The genus name honors the Italian naturalist Luigi Menegazzi [2]. Comprising approximately 70 accepted species of foliose lichens within the family Parmeliaceae, Menegazzia is distinguished by its unique perforated lobes—a morphological feature setting it apart from other genera in the family [3]. The thalli are typically dorsiventral, lobate, and often form rosette-like structures with a hollow and inflated appearance. The upper cortex is perforated, while the lower surface is blackened and lacks rhizines. Internally, the medulla is white and may contain various secondary metabolites, including depsides, depsidones, fatty acids, and pigments [4].

Although the Menegazzia genus exhibits a sub-cosmopolitan distribution, its species show a pronounced concentration in the Southern Hemisphere, particularly in Australasia (including Tasmania and New Zealand) and southern South America [5]. In South America, 20 species have been recognized, with 17 occurring in southern regions such as Chile and Argentina, and 3 in tropical areas [6]. In Australia, 39 species have been recorded, with 30 species identified in Tasmania alone [5]. The genus is less diverse in the Northern Hemisphere, where only a few species, such as M. terebrata and M. subsimilis (H. Magn.) R. Sant., are known to occur [7,8,9].

The taxonomy of Menegazzia is notably complex due to morphological similarities among species, which often render traditional morphological identification insufficient. Many species exhibit overlapping characteristics, and reproductive structures like apothecia are frequently absent or rare, complicating species delimitation [5]. Consequently, chemical characterizations like spot tests have become indispensable in distinguishing species within the genus. For instance, the presence of stictic acid, fumarprotocetraric acid, or norstictic acid can be diagnostic for certain species. Techniques such as thin-layer chromatography (TLC) have been widely employed to detect specific secondary metabolites, and high-performance liquid chromatography (HPLC) to a lesser degree [4].

Ecologically, Menegazzia species are predominantly epiphytic, colonizing the bark of trees in moist, cool habitats, although some species are saxicolous or terricolous [6]. Their sensitivity to environmental changes, particularly air quality and humidity levels, makes them valuable bioindicators. For example, M. terebrata has been identified as an indicator species of clean air in regions like Western Oregon and Washington [10,11]. The presence and abundance of Menegazzia species can thus provide insights into the ecological integrity of forest ecosystems and the impacts of atmospheric pollution [11,12,13].

The distinctive morphology of Menegazzia—notably its dorsiventral thalli with inflated, elevated lobes and characteristic perforations—enhances water retention and gas exchange, facilitating survival in moist, cool habitats [10]. These structural adaptations align with the genus’s preference for high-humidity, low-temperature microclimates, such as temperate rainforests [11]. Consequently, Menegazzia species serve as reliable bioindicators for such environments. Their decline or absence may signal ecological shifts driven by climate change, underscoring their importance in monitoring ecosystem health [10,14].

1.2. Phylogenetic Framework of Menegazzia

Globally, the genus Menegazzia is recognized as a well-supported monophyletic lineage within the family Parmeliaceae. However, its precise phylogenetic position remains under discussion. The earlier hypothesis placing Menegazzia within the Hypogymnioid clade—due to morphological similarities with Hypogymnia Nyl., such as elevated lobes forming rosette-like structures—was refuted by molecular phylogenetic studies [15,16,17]. Subsequent analyses positioned Menegazzia as a sister clade to Coelopogon Brusse & Kärnefelt within the Usneoid clade [18]; this placement was maintained in further studies [19].

The evolutionary history of Menegazzia provides significant insights into Southern Hemisphere biogeography. The estimated crown age of the genus is approximately 21.2 million years (Ma), which postdates the separation of the Antarctic and South American landmasses (~31 Ma). However, its divergence from the nearest common ancestor within Parmeliaceae is dated at around 44.8 Ma. This discrepancy supports the hypothesis that the current distribution of Menegazzia may be shaped more by long-distance dispersal than by ancient vicariant events, although the extinction of ancestral lineages remains a possibility [18].

1.3. Menegazzia Research in Chile

Chile presents a unique biogeographical context characterized by a pronounced latitudinal gradient, the orographic barrier of the Andes, and the longitudinal interruption known as the arid diagonal. This natural barrier plays a central role in the geographic and ecological segmentation of mesic forest habitats and has contributed significantly to the isolation and diversification of forest-dwelling organisms, including lichenized fungi [6].

In the context of South American lichenology, taxonomic studies of Menegazzia gained momentum in the 20th century, beginning in the 1940s with the work of Rolf Santesson [20]. Quilhot and collaborators’ extensive floristic works in Isla Mocha, Aisén and Laguna San Rafael [21,22,23,24] significantly enriched the institutional lichen herbarium of Valparaiso University which facilitated multiple taxonomic advances. In the early 2000s, the Norwegian J. W. Bjerke, mentored by Arve Elvebakk, arrived in Chile to work with Wanda Quilhot, and their combined efforts resulted in the discovery and formal description of several new taxa and also the synonymization of other species [25,26,27]. The naming of Menegazzia wandae commemorated her pioneering contributions to Chilean lichenology, which is reflected in the consolidation of the herbarium with the highest number of Chilean lichen samples, the lichen herbarium of Valparaiso University [25].

In Chile, Menegazzia comprises around 20 species with a markedly disjunct distribution—ranging from the subantarctic forests of the XII Region to isolated relict forests in Fray Jorge National Park (IV Region), where it survives in fog-fed temperate remnants [26,28]. The genus is absent in the hyper-arid and semi-arid zones but reappears south of the VI Region, tracking the continuity of Andean and coastal temperate forests [26,27], with the Conguillio National Park being the area with the highest diversity of Menegazzia species, accounting for a total of 16 [29].

Menegazzia species prefer cold-temperate, humid environments, especially in montane and subantarctic bioclimatic zones, such as the Andean foothills and Patagonia. These areas offer stable humidity and a low thermal amplitude. Species richness and abundance increase with precipitation and decrease with high summer temperatures. Ecologically, Menegazzia shows a strong preference for Nothofagus Blume phorophytes—N. pumilio (Poepp. et Endl.) Krasser, N. antarctica (Forst.f.) Oerst, and N. betuloides (Mirb.) Oerst—which dominate much of its range [6]. These trees offer favorable bark properties and stable microclimates as suggested by the work of Villagra et al. analyzing the distribution of lichens in relation to the microclimate and bark pH, where Menegazzia species were detected in N. antarctica but not in A. araucana [30]. The biogeographic overlap of Nothofagus and Menegazzia suggests a shared ecological history, likely shaped by glacial refugia, dispersal barriers, and climate-induced forest dynamics [6].

The most comprehensive synthesis to date remains the revision of South American Menegazzia species by Bjerke in 2005 [26], which is now updated after 20 years to clarify and complete this work, also including color pictures of almost all the Chilean species of Menegazzia.

2. Distribution and Habitat Preferences of Menegazzia Species

The genus Menegazzia exhibits notable reproductive diversity, with species reproducing either sexually (via ascospores) or asexually (via soredia). This variation in reproductive strategy is associated with distinct geographic and ecological patterns across its range. Fertile, esorediate species (sexually reproducing)—defined as “primary species”—are considered more ancestral and are typically associated with pioneer habitats. Their reproduction depends on the dispersal of fungal spores and re-lichenization, a complex and environmentally sensitive process. As such, fertile species are usually less frequent, more narrowly distributed, and confined to transitional habitats, often being displaced by other species as the habitat becomes either degraded or more stable. In contrast, species that reproduce asexually through soredia—referred to as “secondary species”—are generally more abundant in stable and undisturbed habitats, such as canopy gaps, forest edges, or areas affected by blowdowns and landslides. Their capacity for rapid colonization and vegetative propagation gives them a competitive advantage. These species tend to exhibit broader ecological amplitudes, tolerating a wide range of light, moisture, and temperature conditions [9,26].

In Chile, the ecological niches of Menegazzia species vary significantly in response to microclimatic conditions and forest structure [26]. Observational data and floristic inventories indicate that some species are strongly associated with cold environments, such as those experiencing frequent winter frosts and abbreviated growing seasons, while others are more prevalent in consistently humid, low- to mid-elevation temperate forests. These patterns suggest adaptive specialization to specific thermal and moisture regimes, leading to altitudinal and latitudinal partitioning among co-occurring species. In a preliminary ecological study, Bjerke and Elvebakk [6] examined the habitat preferences of sorediate Menegazzia species in Chile, emphasizing their niche differentiation and adaptability across varied forest types. These investigations underscored how reproductive strategies influence colonization and persistence in heterogeneous environments.

In addition to reproductive differences, Menegazzia species also exhibit ecological preferences related to thallus coloration, which correlates with their chemical composition [31]. Some species display a pale white to greyish thallus, while others appear yellowish to green. The latter group typically contains higher concentrations of usnic acid, a secondary metabolite known to provide protection against solar radiation. This chemical adaptation enables these yellow-green species to thrive in more exposed environments, such as forest edges and canopy gaps, where light intensity is higher. In contrast, whitish-grey species, which generally lack significant amounts of usnic acid, are more commonly found in shaded interior forest habitats where light exposure is limited. This divergence in coloration and chemistry reflects different strategies for coping with environmental stressors and further highlights the ecological diversity within the genus.

Climatic patterns further distinguish the ecological roles of these groups: sorediate species show greater resilience to temperature fluctuations and intermittent moisture stress, while fertile species are usually confined to perennially moist, stable microhabitats. This divergence aligns with successional theory and reflects differing colonization strategies. Thallus coloration also reinforces these ecological trends—yellow-green species, rich in usnic acid, thrive in exposed habitats like forest edges, whereas pale greyish species are more common in shaded interior forests. These combined differences in reproduction, chemistry, and color underscore key adaptive strategies that shape Menegazzia diversity and distribution in Chilean forest ecosystems.

3. Methodology

As the aim of this work was to review all available knowledge on Menegazzia in Chile, a comprehensive bibliographic search was conducted to gather all documents in which Menegazzia lichens were identified or sequenced. This included studies by J.W. Bjerke specifically focused on the genus, as well as articles describing species occurring in Chile and works with floristic or phylogenetic aims that included Chilean Menegazzia species.

For the species descriptions, the main source was Bjerke’s work [7,26,27], complemented with descriptions from Australia, New Zealand, and Tasmania [2,3,5]. The content was simplified and stylistically homogenized by the author.

Most photographs were taken by the author using an iPhone 16 Pro. Three exceptions were included due to the unavailability of samples:

M. megalospora (Räsänen) R. Sant., a rare species endemic to the southernmost regions of Chile and Argentina, was illustrated using an image from the Consortium of Lichen Herbaria; M. confusa P. James and M. pertransita (Stirt.) R. Sant., both reported by Pereira et al., were illustrated with images taken from the original publication [18].

Close-up images were obtained using a USB-CMOS DC.5000 camera coupled to a Stereo Blue 1903-CMEX stereomicroscope. All specimens were morphologically identified based on stereomicroscopic and microscopic examination following published descriptions and identification keys, including a spot test with reactive K, C, KC, and P [7,26,27]. In late 2024, I received a visit from J.W. Bjerke, whose advice significantly improved my identification skills for Menegazzia. A few difficult specimens were confirmed by amplifying the ITS region under the conditions described in [32] and comparing the sequences to the GenBank database using nBLAST [33], in order to validate the morphological identifications (data not shown).

4. Description of Species Distributed in Chile

1. Menegazzia cincinnata (Ach.) Bitter, Hedwigia 40: 172 (1901)

Thallus: Closely attached, forming irregular rosettes, 2–10 cm wide.

Lobes: 1.2–2.0 mm wide, convex, contiguous to imbricate, irregularly branched.

Upper surface: Dull, slightly corrugate, pale yellow to greyish-yellow with black patches towards center; pale brown at apices; slightly maculate.

Perforations: Sparse to numerous, 0.2–0.7 mm wide, rounded or irregular; rims often blackened.

Soralia: Absent.

Lower surface: Black centrally, brown and glossy apically, eperforate.

Medullary cavity: Cottony; white above, yellow-brown toward tips, black below.

Apothecia: Numerous, laminal, to 7 mm wide, short-pedicellate.

Disc: Concave to flat, epruinose, red-brown.

Thalline exciple: Pale brown to concolorous, crenulate to entire (Figure 1), 0.1–0.5 mm.

Ascospores: 8/ascus, 19–28 × 12–18 µm, wall 1.3–2.5 µm.

Pycnidia: Numerous; ostiole brownish.

Chemistry: Usnic acid (major–minor), lecanoric acid (trace in apothecia), thamnolic acid (absent-trace).

Spot tests: K+ yellow (variable), P–, C–.

Distribution and ecology: From 46° S (Laguna San Rafael) to Tierra del Fuego. In humid Nothofagus forests.

2. Menegazzia dispora (Nyl.) R. Sant., Ark. Bot. 30A (no. 11): 13 (1942) Synonymized with M. hollermayeri (Räsänen) R. Sant., by J.W. Bjerke [26]

Thallus: Loosely attached, radiating rosettes, 4–15 cm wide.

Lobes: 1.5–3.5 mm wide, convex, widely branched, often with open gaps (Figure 2).

Upper surface: Smooth, dull centrally, glossy at apices; greenish-grey to brownish.

Perforations: Sparse, 0.3–1.5 mm, rounded/ovoid, gaping; rim plane or slightly elevated.

Soralia: Absent.

Lower surface: Black and scrobiculate centrally; brown-glossy apically, sometimes perforate.

Medullary cavity: White above, pale yellow in apices, black below.

Apothecia: Numerous, laminal, up to 10 mm wide, short-pedicellate.

Disc: Concave to plane, epruinose, red-brown.

Thalline exciple: Concolorous, crenulate in youth, entire in age, 0.1–0.4 mm wide.

Ascospores: 2/ascus, 38–56 × 25–36 µm, wall 1.8–4.5 µm.

Pycnidia: Abundant; ostiole dark brown-black.

Chemistry: Hypoconstictic acid (major), hypostictic acid (minor), acetylhypoconstictic acid, yellow pigments.

Spot tests: K+ yellow, C–.

Distribution and ecology: From 38° S (Conguillío) to 53° S (Magallanes). Frequent in Valdivian and Patagonian forests.

The synonymization of M. dispora and M. hollermayeri by J.W. Bjerke [26] was based on the inconsistency of the differential character which was crenulated thalline exciple in M. dispora and thin thalline exciple in M. hollermayeri. Molecular analyses should confirm this synonymization.

3. Menegazzia megalospora (Räsänen) R. Sant., Ark. Bot. 30A(no. 11): 21 (1942)

Thallus: Firmly attached, compact rosettes, 2–5 cm wide.

Lobes: 0.5–1.5 mm wide, short, imbricate, subdichotomous.

Upper surface: Glossy, grey or greenish-grey; blackened centrally, pale brown apically; occasionally pruinose (ice-blue/white).

Perforations: Sparse or absent, small (0.1–0.5 mm), rim plane or slightly rolled.

Soralia: Absent.

Lower surface: Glossy, black centrally, brown apically.

Medullary cavity: White or black above, black below.

Apothecia: Numerous, small (0.8–1.5 mm), sessile or shortly pedicellate.

Disc: Concave, red-brown, epruinose.

Thalline exciple: Grey to black, crenulate, incurved, 0.2–0.3 mm.

Ascospores: 2/ascus, 60–98 × 32–60 µm, wall 5–12 µm.

Pycnidia: Numerous; ostiole dark.

Chemistry: Stictic acid, constictic acid, cryptostictic acid, menegazzic acid.

Spot tests: K+ yellow, C–.

Distribution and ecology: 42°20′ (Chiloé) to 54°30′ (Isla Grande). Epiphyte in lush Nothofagus betuloides rainforest. This species is particularly rare and no fresh material was available for the picture (Figure 3).

4. Menegazzia opuntioides (Müll. Arg.) R. Sant., Ark. Bot. 30A(no. 11): 25 (1942)

Thallus: Loosely to firmly attached, irregular rosettes, 3–7 cm wide.

Lobes: 0.5–4.0 mm wide, 0.5–5.5 mm long; inflated, bud-like; segments ellipsoid with narrow articulations (Figure 4).

Upper surface: Glossy on young segments, dull on older; lead-grey to black; pale brown apically; black at joints.

Perforations: 0–2 per lobe, laminal or marginal, rounded or conical, 0.1–0.5 mm.

Soralia: Absent.

Lower surface: Scrobiculate, black centrally, brown at tips.

Medullary cavity: White or black above, black below and at articulations.

Apothecia: 1.2–2.5 mm, central, short-pedicellate.

Disc: Concave to flat, epruinose, dark brown.

Thalline exciple: 0.2–0.3 mm, black or concolorous, crenulate, slightly incurved.

Ascospores: 2/ascus, 62–95 × 34–55 µm.

Pycnidia: Sparse; ostiole dark.

Chemistry: Barbatic acid (major), demethylbarbatic acid (minor), other unidentifieds.

Spot tests: K+ yellow, C–.

Distribution and ecology: 40°30′ to 54°30′ (Isla Grande). Epiphyte in temperate rainforest.

5. Menegazzia valdiviensis (Räsänen) R. Sant., Ark. Bot. 30A(no. 11): 25 (1942)

Thallus: Firmly attached, irregular rosettes, 5–10 cm wide.

Lobes: 1.5–3.0 mm wide, convex, crowded, irregularly branched.

Upper surface: Glossy in parts, greenish-grey to pale yellow-green, pale brown apices, black margins.

Perforations: Sparse to many, small (0.05–0.7 mm), oval or round, rim plane.

Soralia: Absent.

Lower surface: Black centrally, brown and glossy at tips, perforate.

Medullary cavity: White above, black below.

Apothecia: Sparse to numerous, rounded, short-pedicellate; hymenial medulla often yellow-orange.

Disc: Concave to flat, red-brown, epruinose.

Thalline exciple: 0.1–0.2 mm, entire, glossy, cracks in age (Figure 5).

Ascospores: 0–8/ascus, irregular in shape when poorly developed; 19–29.5 × 11–18 µm when mature.

Pycnidia: Numerous; ostiole brownish.

Chemistry: Lecanoric acid (major), thamnolic acid (variable), usnic acid (trace).

Spot tests: K+ yellow (in medulla under apothecia), C–.

Distribution and ecology: 37°40′ (Conguillío/Nahuelbuta) to southernmost Chile. Common in Valdivian rainforest.

6. Menegazzia wilsonii (Vain. ex Räsänen) Bjerke, Mycotaxon 91: 439 (2005)

(formerly Pannoparmelia wilsonii) synonym M. albida (Zahlbr.) R. Sant.

Thallus: Firmly attached, orbicular rosettes 2–15 cm wide (Figure 6).

Lobes: 0.8–2.0 mm wide, flat to slightly concave, crowded, flabellate, partly overlapping; often with toe-like lateral branches.

Upper surface: Smooth; glossy at apices, dull centrally; grey-white to pale green, turning brown-black with age; pale brown tips, blackened margins.

Perforations: Numerous, per lobe, narrowly to broadly oval, smaller at apices (0.1–0.9 mm); rim flat or inrolled.

Soralia/Isidia: Absent.

Lower surface: Black centrally, pale brown and glossy near apices, eperforate.

Medullary cavity: White above, black below.

Apothecia: Sessile to short-pedicellate, 0.6–1.5 mm wide; usually numerous, laminal.

Disc: Plane in maturity, concave when young, brown, epruinose, often degraded.

Thalline exciple: Concolorous to slightly blackened; entire, glossy, smooth with cracks, 0.1–0.2 mm.

Ascospores: 8/ascus, hyaline, 19–29 × 12–18 µm.

Pycnidia: Numerous; ostiole dark brown.

Chemistry: Atranorin and chloratranorin (trace–major); lichesterinic and protolichesterinic acids (major).

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: 36°50′ (Termas de Chillán) to southern Tierra del Fuego. Found in Andean Nothofagus forests, typically epiphytic.

7. Menegazzia chrysogaster Bjerke & Elvebakk [27]

Thallus: Firmly attached; lobes wide, slightly convex and partly glossy.

Lobes: Pale grey-green, often pruinose at tips; blackened margins toward center.

Upper surface: Smooth to slightly maculate; often with ochre tint on upper medullary cavity (Figure 7); UV–.

Perforations: Present, sparse to frequent, small to moderate in size, rounded, often black-rimmed.

Soralia: Crateriform or slightly convex; white to pale yellow; laminal, frequently well-defined.

Lower surface: Black toward center, brown apically, often glossy.

Apothecia: Rare or absent.

Chemistry: Atranorin, stictic acid, constictic acid, cryptostictic acid; ochre-yellow pigments.

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: 36°50′ (Termas de Chillán) to 53°22′ (Región de Magallanes). Epiphyte in montane forest and temperate rainforest.

8. Menegazzia fumarprotocetrarica Calvelo & Adler (1996)

Thallus: Thin, closely attached; greenish-grey; glossy upper surface. (Figure 8)

Lobes: Narrow (<1.5 mm); upper cortex glossy; lobes undulate to slightly convex.

Perforations: Small, sparse, rim flat or slightly raised.

Soralia: Prominent, on pustules 1–2 mm tall; lacerate or rupturing; mostly laminal.

Lower surface: Black or dark brown; eperforate.

Apothecia: Rare.

Chemistry: Fumarprotocetraric acid (major).

Spot tests: K–, C–, KC–, P+ orange-red (confirmatory).

Distribution and ecology: 37°49′ (Nahuelbuta) to 53°22′ (Península Brunswick). Rare; grows in humid Nothofagus forests and wet temperate zones.

9. Menegazzia globulifera R. Sant., Ark. Bot. 30A(no. 11): 30 (1942)

Thallus: Closely attached to loosely attached; often forming broad rosettes.

Lobes: ~1–3 mm, smooth, slightly convex, pale greenish-yellow when fresh.

Upper surface: Shining, yellow-green with scattered vesicular soralia; UV–.

Perforations: Sparse; small, rounded.

Soralia: Vesicular, helmet-shaped, pale yellow-green; not pustulate; laminal. (Figure 9)

Lower surface: Brown to black, glossy.

Apothecia: Rare.

Chemistry: Usnic acid (in cortex), lecanoric acid (in medulla).

Spot tests: K–, C–, KC–.

Distribution and ecology: 36°50′ (Termas de Chillán) to 55°05′ (Navarino Island). Pan-austral; on bark or shrubs in cool-temperate forests.

10. Menegazzia kawesqarica Bjerke & Elvebakk, Mycotaxon 78: 376 (2001)

Thallus: Closely attached; forms irregular rosettes.

Lobes: Broad (up to 4 mm), convex, conspicuously maculate (Figure 10); often corrugated; greyish and patchily blackened.

Upper surface: Smooth to corrugate; sorediate; margins entire to slightly crenulate.

Perforations: Present, small and sparse.

Soralia: Large, convex, sometimes confluent; granular to pustulate; laminal.

Lower surface: Black to brown, glossy near apices.

Apothecia: Rare.

Chemistry: Atranorin, stictic acid, menegazziaic acid, cryptostictic acid, constictic acid.

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: 37°49′ (Nahuelbuta) to 53°22′ (XII Region); endemic to southern South America; found in Valdivian and Patagonian rainforest on bark.

11. Menegazzia magellanica R. Sant., Ark. Bot. 30A(no. 11): 23 (1942)

Thallus: Closely attached, forming small to medium rosettes; entire thallus often appearing smooth and emaculate.

Lobes: Convex, 1.5–3 mm wide, sometimes pruinose; margins slightly crenulate; emaculate and greyish-green to pale green.

Upper surface: Smooth, slightly pruinose, especially at lobe tips; UV–; maculae occasional.

Perforations: Sparse, 0.2–0.8 mm, rounded, rim not elevated.

Soralia: Maniciform (depression or cavity-like), connected to the internal medullary cavity via an open duct; white or pale yellow, K+ yellow (Figure 11).

Lower surface: Black centrally, brown near apices; shiny and often perforate at margins.

Apothecia: Occasionally produced; 2-spored asci are typical.

Chemistry: Atranorin, stictic acid, constictic acid, cryptostictic acid, menegazziaic acid.

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: Strictly endemic to southernmost South America (50°50′ to 55°30′, XII Region). Occurs on bark and wood in subantarctic forests.

12. Menegazzia neozelandica (Zahlbr.) P. James, in James & Galloway, Flora of Australia, Vol. 54. Lichens—Introduction, Lecanorales 1 (Canberra): 313 (1992)

Thallus: Closely attached, lobes moderately broad, forming rosettes 4–10 cm.

Lobes: ~1–3 mm wide, convex, irregularly branched, sometimes overlapping.

Upper surface: Glossy, pale green to greyish-green; maculate or epruinose; UV–.

Perforations: Numerous, gaping, often surrounded by elevated rims; up to 1.5 mm wide (Figure 12).

Soralia: Generally marginal and laminal; develop around perforations, forming collars or rings.

Lower surface: Brown to black, perforate in older thalli.

Apothecia: Rare or absent.

Chemistry: Atranorin, stictic acid, cryptostictic acid, constictic acid, menegazziaic acid.

Spot tests: K+ yellow, C–.

Distribution and ecology: Widely distributed in southern Chile from 30°30′ (Fray Jorge) and Juan Fernández Islands to 52°40′ (Isla Riesco). Occurs on bark, twigs, and occasionally rock; prefers open areas in humid montane or oceanic climates. Widespread pan-austral species.

13. Menegazzia sanguinascens (Räsänen) R. Sant., Ark. Bot. 30A(no. 11): 28 (1942)

Synonymized with M. norsorediata Adler & Calvelo by Bjerke [26]

Thallus: Loosely to closely attached; forms irregular patches (Figure 13).

Lobes: Broad (2–3 mm), smooth, shining, emaculate, with toe-like lateral lobules.

Upper surface: Pale green to greenish-grey, more vivid green when moist; UV+ white.

Perforations: Small (~0.2–0.8 mm), numerous, gaping, slightly elevated margins.

Soralia: Neat, convex, laminal; evenly dispersed or clustered; white to pale.

Lower surface: Black to brown; glossy at apices.

Apothecia: Rare; occasionally present in mature thalli.

Chemistry: Atranorin, thamnolic acid, hypothamnolic acid.

Spot tests: K+ yellow, C–, P+ yellow to orange (confirmatory), KC–.

Distribution and ecology: 37°49′ (Nahuelbuta) to 55°30′ (Isla Hose); common in southern Argentina and Chilean Patagonia; epiphytic in cool temperate forests.

14. Menegazzia subpertusa P. James & D.J. Galloway 1983

Thallus: Closely attached, forming compact to irregular rosettes (Figure 14).

Lobes: Convex, irregularly branched, often imbricate, 1–2 mm wide.

Upper surface: Smooth, pale grey with slightly shining apices; minutely pruinose in parts.

Perforations: Small (<0.5 mm), rounded, rim flat.

Soralia: Laminal, convex, often grouped; usually <0.5 mm wide; white, granular.

Lower surface: Black centrally, brown to black apically.

Apothecia: Common; laminal, contain 2-spored asci; up to 2 mm wide.

Chemistry: Atranorin, stictic acid, cryptostictic acid, menegazziaic acid, constictic acid.

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: 36°50′ (Las Trancas) to 54°49′ (Isla de los Estados, Argentina). Widespread in cool humid forests of the southern Andes.

15. Menegazzia tenuis R. Sant., Ark. Bot. 30A(no. 11): 27 (1942)

Thallus: Closely attached, forming irregular, often small rosettes (Figure 15).

Lobes: Very narrow (0.3–0.8 mm), sinuous, sometimes branched or intertwined, appearing delicate.

Upper surface: Smooth, pale grey to greyish-green, slightly pruinose near apices; UV–.

Perforations: Numerous, small (0.1–0.3 mm), rounded to ellipsoid, with flat rims.

Soralia: Small, laminal to submarginal, maniciform (depressed, cavity-like), containing only a few granules; usually <0.3 mm wide.

Lower surface: Black to dark brown, eperforate, slightly glossy apically.

Apothecia: Rare or absent.

Chemistry: Atranorin, lichesterinic acid, protolichesterinic acid.

Spot tests: K+ yellow, C–, KC–.

Distribution and ecology: Restricted to southernmost Chile and Argentina south of 52°40′ S. Occurs in hyper humid temperate forest zones, mostly on Nothofagus bark and twigs.

16. Menegazzia violascens Bjerke, Mycotaxon 91: 448 (2005)

Thallus: Loosely attached, forming irregular rosettes or spreading patches.

Lobes: Broad (up to 3.5 mm), convex, smooth, shiny, emaculate; with occasional toe-like lateral lobes.

Upper surface: Grey-green to greenish-grey, UV+ white; shining and slightly pruinose at tips.

Perforations: Sparse, small (~0.2–0.4 mm), with flat rims.

Soralia: Neat, convex, laminal; soredia coarse-granular, white to pale grey.

Lower surface: Dark brown to black, slightly wrinkled; eperforate.

Apothecia: Not observed.

Chemistry: Atranorin (minor–major), hypotamnolic acid (major), thamnolic acid (trace–minor).

Spot tests: K+ violet (medulla and soralia), C–, P+ pale orange (Figure 16).

Distribution and ecology: Endemic to Chile, from the Juan Fernández Islands south to 37°40′. Found in humid montane forests, often on Myrtaceae or Nothofagus bark.

17. Menegazzia wandae Bjerke, Lichenologist 33(2): 117 (2001)

Thallus: Corticolous, loosely to closely attached, forming irregular patches up to 10 cm wide.

Lobes: Sinuous, 0.6–2.0 mm wide, inflated, pale grey to grey-brown; terminal branches wide-angled, emaculate (Figure 17).

Upper surface: Smooth to finely corrugated, often shiny at apices; black margins common near the center.

Perforations: Sparse to scattered, small (0.05–0.5 mm), rounded or irregular; may be associated with pustules.

Soralia: Laminal, formed on low pustules (≤1.5 mm); lacerate, irregular, often contiguous; up to 2.5 mm wide.

Lower surface: Dark brown to black, shiny near margins, with longitudinal wrinkles.

Apothecia: Not observed.

Pycnidia: Rare; ostiole black. Conidia ~5–7 × 0.5 µm.

Chemistry: Atranorin (trace–minor), thamnolic acid (major), three unidentified accessory compounds.

Spot tests: K+ yellow, C–, P+ pale orange (medulla, weak).

Distribution and ecology: Endemic to Chile; 38°30′ (Malleco) to 46°40′ (Laguna San Rafael). In Valdivian rainforest on Nothofagus alpina, usually in shaded microhabitats.

18. Menegazzia pertransita (Stirt.) R. Sant., Ark. Bot. 30A(no. 11): 12 (1942)

Thallus: Foliose, loosely attached, forming irregular rosettes up to 10 cm in diameter.

Lobes: Broad (2–4 mm wide), convex, overlapping, with rounded apices (Figure 18).

Upper surface: Smooth to slightly wrinkled, pale grey to greenish-grey, often with a dull sheen.

Perforations: Numerous, large (up to 2 mm), laminal, with inrolled margins.

Lower surface: Black, shiny, eperforate.

Medullary cavity: White, cottony.

Apothecia: Common, laminal, pedicellate; discs concave to flat, pale red-brown; thalline exciple smooth, entire.

Ascospores: 2 per ascus, 40–52 × 26–31 µm; wall 2.5–4.5 µm thick.

Pycnidia: Numerous, immersed, blackish around ostiole.

Conidia: 6–7 × 0.5 µm.

Chemistry: Cortex K+ yellow (atranorin); medulla K–, C–, KC–, P– (caperatic acid).

Distribution: Reported from New Zealand and Australia. In Chile, it has been recorded only once in the Bío-Bío Region (Termas de Chillán and Las Trancas).

Ecology: Corticolous, growing on bark and dead wood in humid forest environments.

19. Menegazzia confusa P. James 1987

Thallus: Closely appressed, forming rosettes up to 5 cm in diameter (Figure 19).

Lobes: Short (1.5–3.5 mm wide), inflated, contiguous, irregularly dichotomously branched; central lobes congested, folded, convex.

Upper surface: Rugose, matte, shining and smoother towards tips, pale grey to grey, rarely blackened laterally.

Perforations: Frequent, evenly distributed, up to 2 mm wide, laminal; margins depressed.

Lower surface: Black, eperforate.

Medullary cavity: Coarsely tomentose, purplish brown-black.

Apothecia: Frequent, 4–5 mm wide, laminal, sessile to subpedicellate; disc concave to flat, pale red-brown; exciple smooth, entire, becoming uneven and sparingly lacerate.

Ascospores: 2 per ascus, 40–52 × 26–31 µm; wall 2.5–4.5 µm thick.

Pycnidia: Numerous, immersed, blackish around ostiole, sometimes coalescing and blackening upper surface.

Conidia: 6–7 × 0.5 µm.

Chemistry: Cortex K+ yellow (atranorin); medulla K–, C–, KC–, P– (caperatic acid).

Distribution: Endemic to southeastern Australia, including New South Wales, Victoria, and Tasmania. In Chile, it has been recorded only once in the Bío-Bío Region (Termas de Chillán and Las Trancas).

Ecology: Occurs in dry sclerophyllous open country and forest margins, on bark and dead wood of various trees and shrubs.

20. Menegazzia terebrata (Hoffm.) A. Massal., Neagenea Lich: 1 (1854)

Neagenea Lichenum: 1, 1854. Basionym: Lobaria terebrata Hoffm.—Deutschl. Fl.: 151, 1796.

Thallus: foliose, dorsiventral, forming up to 10 cm wide, regular rosettes, but often dying in central parts.

Lobes: closely adnate, up to 2 (–2.5) mm wide, rounded at apices, contiguous for much of their length, swollen and hollow inside.

Upper surface: grey to greenish grey, often brownish at the ends and along margins, smooth and glossy.

Perforations: dark round to oval, mostly <1 mm wide.

Soralia: whitish, rounded, more or less stalked, capitate, to 1.5 mm wide, not marginally proliferating soralia which later often become ring-shaped (maniciform) with a central opening to the medulla, but never lacerate (Figure 20).

Apothecia: extremely rare, lecanorine, with a brown disc and a persistent thalline margin

Ascospores: asci 2-spored, ellipsoid, 50–70 × 30–36 µm, thick-walled.

Chemistry: upper cortex with atranorin, medulla with stictic, constictic, menegazziaic acids, with or without low amounts of norstictic acid. upper cortex K+ yellow, C–, KC–, P–; medulla K+ yellow, C–, KC–, P+ yellow-orange, UV–.

5. Discussion

This study presents the first update on the genus Menegazzia in Chile in over two decades, integrating floristic inventories not focused on but including Menegazzia species with recent phylogenetic and molecular data on the Parmeliaceae family with valuable insights on the Menegazzia genus including its taxonomic placement, as well as the radiation time of the genus and divergence time from the sister genus Coelopogon [18,19]. It also includes an updated dichotomous key and color photographic documentation to support accurate species identification—especially useful given the morphological convergence and reduced reproductive structures in the genus.

There are also critical taxonomic uncertainties requiring resolution. For example, some authors registered M. hollermayeri, M. albida, and M. norstictica [22,23,29], while J.W. Bjerke considered these as synonyms of the valid names M. dispora, M. wilsonii, and M. sanguinascens [26]. Some species reported from Chile—such as Menegazzia pertransita, M. confusa, and M. terebrata—have been documented only once and their identifications should be re-evaluated. The records of M. pertransita and M. confusa, published by Iris Pereira and collaborators [28] with accompanying photographs, raise doubts: the specimen identified as M. confusa closely resembles M. globulifera, while the image labeled as M. pertransita is morphologically consistent with M. valdiviensis. The record of M. terebrata, listed in the GBIF database, lacks photographic evidence and an associated herbarium voucher, making its confirmation currently impossible. These cases highlight the importance of rigorous morphological and molecular verification in future fieldwork and taxonomic studies. Given their high ecological specificity, Menegazzia species also offer considerable potential as bioindicators. Their sensitivity to air quality and climatic variables—especially humidity and temperature—makes them valuable tools for monitoring environmental change [6]. Future research should prioritize the systematic use of these species in biomonitoring programs.

The divergence time between Menegazzia and its sister genus Coelopogon—estimated at ~44.8 Ma [18]—predates the final separation of Southern Hemisphere landmasses at ~34 Ma [34], indicating that vicariance alone cannot account for the current species distributions. This supports the hypothesis of long-distance dispersal in shaping the genus’s biogeography, including the presence of Northern Hemisphere species such as M. terebrata and M. subsimilis. Menegazzia remains an exemplary group for addressing broader questions in southern temperate ecology, including evolutionary radiation, biogeographic disjunction, and ecological adaptation. However, the limited application of molecular tools to Chilean taxa has left significant gaps in our understanding of species boundaries, cryptic diversity, and phylogeographic structure. Likewise, ecological differentiation between sorediate and fertile species—particularly in the context of habitat fragmentation, forest succession, and climate variability—remains insufficiently studied. Moving forward, integrative approaches that combine morphological taxonomy, chemotaxonomy, molecular phylogenetics, and ecological modeling will be essential to reassessing species diversity, clarifying evolutionary relationships, and informing conservation strategies for this emblematic genus across Chile and the Southern Hemisphere.

6. Dichotomous Identification Key

1. Thallus without soralia; apothecia common.	2
Thallus with soralia; apothecia rare.	8
2. Lobes multiply segmented with numerous, globose to broadly ellipsoid lobe segments; barbatic acid in medulla (K+ yellow).	M. opuntioides
Lobes not segmented; lobe width even, fatty acids or other depsides than barbatic acid present in medulla.	3
3. Asci 2-spored; spores large, longer than 35 μm, often up to 95 μm long.	4
Asci 8-spored, or with variable numbers of spores from 1 to 8 and then often associated with underdeveloped asci; spores small, shorter than 30 μm.	7
4. Lobes wide, 1.5–3.5 mm, convex, greyish, loosely attached; apothecia large (3–9 mm); hypostictic acid complex in medulla.	M. dispora (synonym M hollermayeri)
Lobes narrow, 0.5–1.8 mm, flat or slightly concave, greyish or brownish, firmly attached; apothecia small, to 2.0 mm; stictic acid (K+ yellow, P+ orange-red) complex in medulla.	5
5. Lobes often dark brownish, especially towards tips; lobe tips dull, often slightly pruinose; perforations few, sometimes almost absent; southern South America, 2 spores per ascus and high size.	M. megalospora
Lobes grey-green, occasionally pale brown towards tips; lobe tips shining, epruinose; perforations few to numerous.	6
6. Lobes grey to greyish-green, sometimes dark brown towards center, short, imbricate; perforations oval to elongate; medulla in apothecia white; lichesterinic and protolichesterinic acids in medulla.	M. wilsonii
Lobes greenish, yellowish-green or distinctly yellow, not very greyish; not brownish towards center, long, radiating; perforations rounded to broadly ellipsoid; medulla in apothecia yellow-orange or white; lecanoric acid in medulla.	7
7. Thalline exciples of apothecia crenulate and slightly corrugate; lobes distinctly yellow or yellow-green (paler in shade forms); asci well-developed, 8-spored.	M. cincinnata
Thalline exciples of apothecia thin, smooth and not crenulate; lobes greenish or yellow-green; asci often underdeveloped, with 0–8 spores.	M. valdiviensis
8. Soralia derived from inflated vesicles or in helmet-shaped extensions of the lobes; lobes yellow-green; usnic acid in upper cortex.	M. globulifera
Soralia not vesicular in origin; lobes greyish or greyish-green; atranorin in upper cortex.	9
9. Soralia predominantly associated with perforations; stictic acid complex (K+ yellow) in medulla.	M. neozelandica
Soralia not, or only in exceptional cases, associated with perforations; stictic acid complex present or absent.	10
10. Soralia maniciform or derived from pustules, normally showing an open duct to the medullary cavity.	11
Soralia convex to subcapitate, only rarely with an open duct to the medullary cavity.	16
11. Soralia formed on 1–3 mm tall pustules; tip of pustules lacerate or convex.	12
Soralia not raised substantially above the upper surface; lobes not pustulate.	13
12. Pustules with a well-defined, convex, sorediate apex; fumarprotocetraric acid in medulla (C–, K+ brown).	M. fumarprotocetrarica
Pustules lacerate, not convex; stictic acid (K+ yellow) complex or norstictic acid (K+ red) in medulla.	M. magellanica
13. Lobes flat to slightly convex; soralia laminal; fumarprotocetraric acid in medulla; apothecia very rare.	M. pertransita
Soralia small; few soredia in each soralium; perforations mostly oval-ellipsoid; apothecia not known; protolichesterinic and lichesterinic acids (C–, K–) in medulla.	M. tenuis
14. Soralia variable; soredia numerous; perforations ± rounded; occasionally fertile; stictic acid complex in medulla.	15
15. Upper surface of medullary cavity yellow-orange and UV+ pale orange.	M. chrysogaster
Upper surface of medullary cavity white or brown-black, with or without orange patches.	16
16. Lobes greyish to salad-green on fresh material, emaculate, often with toe-like laterals; soralia scattered, not very confluent; soralia and medulla UV+ sky blue and K+ violet due to hypothamnolic acid.	M. violascens
Lobes greyish, slightly to prominently maculate, without toe-like laterals; soralia and medulla UV–, not K+ violet; stictic acid complex or norstictic acid in medulla.	17
17. Soralia small (0.2–0.6 mm), not confluent, occasionally in groups; apothecia rare or common; stictic acid complex in medulla.	18
Soralia variable, chemistry indistinct or weakly reactive (K± yellow, P–); species often confused with others.	M. confusa
18. Soralia mostly protruding from lobe tips, occasionally laminal; lobes epruinose, glossy, ± flat; apothecia rare; the Neotropics.	M. terebrata
Soralia mostly laminal; lobes slightly pruinose, faintly glossy, often convex; apothecia common; southern South America.	M. subpertusa
19. Lobes only slightly maculate; soralia and medulla occasionally with orange patches due to norstictic acid (K+ red).	M. sanguinascens
Lobes reticulately maculate; medulla greyish-white, without orange patches; stictic acid (K+ yellow) complex in medulla.	M. kawesqarica