Heterodermia comosa (Eschw.) Follmann & Redón, Willdenowia

Mongkolsuk, Pachara, Meesim, Sanya, Poengsungnoen, Vasun, Buaruang, Kawinnat, Schumm, Felix & Kalb, Klaus, 2015, The lichen family Physciaceae in Thailand-II. Contributions to the genus Heterodermia sensu lato, Phytotaxa 235 (1), pp. 448-450 : 448-450

2. Heterodermia comosa (Eschw.) Follmann & Redón, Willdenowia 6: 446 (1972) ( Figs. 1F , 4A, 4B )

Parmelia comosa Eschw. , in K.F.P. von Martius, Icon. Pl. Cryptog. 2: 26 (1828); Anaptychia comosa (Eschw.) A. Massal., Mem. Lichenogr. 39 (1853); Physcia comosa (Eschw.) Nyl., Syn. Meth. Lich. 1(2): 416 (1860). Type:— BRAZIL. Pará; near Porta de Môz, on branches of tree; not located but based on illustration tab. XII, fig. 1, fide S.Kurokawa, Beih. Nova Hedwigia 6: 103 (1962). Epitype (designated by Moberg & Nash, 1999: 4):— BRAZIL. Minas Gerais, Caldas, ad arbores, August 1873, H. Mosén (UPS!)

Thallus foliose to subfruticose, forming small rosettes or tufts of ascending lobes, 3–7 cm wide. Lobes 0.7–5.0 (–8.0) mm wide, sublinear, spathulate or paddle-shaped, convex, rarely branched, ascending or suberect, partially imbricate, with rounded apices when sterile, ciliate; cilia prominent, usually simple, marginal and laminal, whitish, 2–4 mm long. Upper surface white to grayish white, sorediate; soredia on the undersides of lobe tips; marginal rhizines whitish, mostly simple, sometimes furcate or irregularly ramified. Medulla white. Lower surface ecorticate, arachnoid, uniformly white (South American material, including the epitype, partly yellow-brown), apically sorediate when sterile, erhizinate. Apothecia subterminal to terminal on ascending lobes, substipitate, 1–5(–10) mm wide; margin crenate or lobulate, ciliate; disc dark brown, densely whitish gray pruinose. Ascospores Polyblastidia -type, narrowly ellipsoid to fusiform, with 2–3 sporoblastidia, 31–35 × 13–16 µm. Pycnidia not seen. Chemistry: Cortex K + yellow, C –, KC–, P + yellow; medulla K + yellow, C –, P –; pigmented lower surface K + violet; containing atranorin (major), zeorin (major), 6α-acetoxyhopane-16β,22-diol (minor), ± 7-chloroemodin (minor to trace) .

Distribution and habitat:—Occurs on the twigs or trees and shrubs in a garden situated in forest remnants at 750–800 m above sea level; also in Australia, North, Central and South America, Africa and Asia.

Remarks: — This lichen is characterized by spathulate or paddle-shaped lobes with cilia on the upper surface, and soralia beneath lobe apices. It is possible that the type race from South America, with the yellow-brown pigmented lower surface, is a different species to the Palaeotropical taxon. However, specimens lacking the anthraquinone (7-chloroemodin) are also known from the Neotropics. The anthraquinone is distinctly visible on the epitype, which was collected in 1873.

Material reported from Thailand:— Chiang Mai: Mushroom Research Centre along road to Pae , on bark in Camellia garden in forest remnants, 750–800 m, 19°07'11'' N, 98°44'01'' E, 1–3 July 2004, Aptroot 61359 ( ABL). ( Aptroot et al. 2007: 104) .

Selected specimens examined: BRAZIL. Minas Gerais: Serra da Mantiqueira; Vila Monte Verde, ca. 30 km E of Camanducaia , on a deciduous tree at the edge of in a light and ± dry forest, 1850 m, 22°50’ S, 46°00’W, 7–11 September 1978, K. Kalb & G. Plöbst (herb. Kalb 37798); Brazil . Minas Gerais: Serra do Espinhaço; Serra do Caraça , above the monastery Caraça, in an open cerrado, 1450 m, 20°10’ S, 43°30’ W, 8. July 1978, K. Kalb & G. Plöbst (herb. Kalb 37787) — PARAGUAY. Presidente Hayes: Gran Chaco; ca. 50 km NW of Filadelfia , at the edge of a dense forest with many cacti, 250 m, 22°07 S, 60°30' W, 6 June 1980, K. Kalb (herb. Kalb 37804) .

Figures

FIGURE 1. A. Heterodermia pseudospeciosa, longitudinal section through thallus showing the periclinal hyphae of the upper cortex forming a prosoplectenchyma characterizing Heterodermia s.lat. (scale 20 µm). B. Physcia erumpens, longitudinal section through thallus showing the anticlinal hyphae of the upper cortex forming a paraplectenchyma, characteristic for Physcia s.lat. C. Leucodermia leucomelos f. albociliata, lobes dichotomously branched, ribbon-like with conspicuous long marginal rhizines. D. Polyblastidium subneglectum (Elix) Kalb, comb. nov., Mycobank MB 813851, Basionym: Heterodermia subneglecta Elix, Australas. Lichenol. 68: 17 (2011), lobes irregularly to sympodially branched, appressed to the substrate not or only slightly ascending towards the tips. E. Heterodermia galactophylla, tufts of apically ascending lobes with white marginal rhizines. F. Heterodermia comosa, thallus subfruticose, lobes affixed mainly near the base, with paddle-shaped tips and white cilia.

FIGURE 4. A. Heterodermia comosa, cilia orginating from the upper surface (scale 2 mm). B. Heterodermia comosa, cilia orginating from the exciple of the apothecia (scale 1 mm). C. Heterodermia echinata, white marginal rhizines, some becoming dark at the tips (scale 5 mm). D. Leucodermia leucomelos f. albociliata, ± white, simple marginal rhizines (scale 5 mm). E. Leucodermia boryi, black branched marginal rhizines (scale 0.5 cm). F. Polyblastidium propaguliferum, black, branched, marginal rhizines (scale 1 mm).