Observation 166070: Leptogium lichenoides (L.) Zahlbr.
When: 2014-05-28
Who: zaca
No herbarium specimen

Notes: The overall appearance of this specimen is that of Leptogium gelatinosum. In fact, this specimen has :
- Convoluted rounded lobes forming a compact tuft of ~2.5 cm, +/- erected;
- Upper surface dark-brown with a shade of grey, wrinkled;
- The apothecia are smooth, flat or slightly concave, with true exciple raised.
However some of its features does not correspond to that species:
- Grew in a siliceous rock habitat, among mosses;
- Has only a few hidden apothecia;
- The upper/lower surface of thallus has a layer of composed by one/several cells;
- The spores are of the biggest in the genus,
in average: Me = 42.3 × 16.3 um ; Qe = 2.6 (N=32), in the ranges: 35.8-48.6 × 14.9 – 18.2 um.

Having a quite recent reference of the Leptogium existing here, I started with a search of the species with muriform spores, which are (with its dimensions in brackets):
Leptogium biatorinum [20–25 × 10–12 μm]
Leptogium burgessii [25–45 × (10)15–20 μm]
Leptogium coralloideum [25–35 × 12–18 μm]
Leptogium cyanescens [22–28 × 10–12.5 μm]
Leptogium gelatinosum [27–40 × (10)15–20 μm]
Leptogium lichenoides [37–47 × 17–22 μm]
Leptogium palmatum [35–45 × 16–18 μm]
Leptogium rivale [25–30 × 10–12.5 μm]
Leptogium schraderi [32.5–37.5 × 15 μm]
Leptogium subtile [20–25 × 9–10 μm]
Leptogium tenuissimum [16–28(30) × 7.5–10(12) μm]

One can immediatly exclude most of the species above only on the basis of the dimensions of the spores, including L. gelatinosum, since the average lenght obtained is greater than the maximum of the lenght of its spores. Only two remain: L. lichenoides and L. palmatum. Recall that the latter species is very common here and I already devoted to it observation 166019, being completely different. Therefore, only L. lichenoides can be. It is known that this species is very similar to L. gelatinosum, but usually has conspicuous isidia and apothecia are rare. After all, I think that this is the correct choice.

Images

422899
422900
Hidden apothecia;
422901
Microscopy 1: Section of thallus;
422902
Microscopy 2: Apothecial section
422903
Microscopy 3: Apothecial section (pressing the cover slip);
422904
Microscopy 3: Asci;
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Microscopy 4: Asci;
422906
Microscopy 5: Spores;
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Microscopy 6: Spores.

Proposed Names

58% (1)
Eye3 Eyes3
Used references: López de Silanes et al., Leptogium in mainland Portugal, Sydowia 64(1): 67-102, 2012.
Based on microscopic features

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Created: 2014-05-29 06:12:52 AEST (+1000)
Last modified: 2014-05-29 06:14:38 AEST (+1000)
Viewed: 45 times, last viewed: 2017-06-18 21:17:50 AEST (+1000)
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