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Lichen: Caloplaca thallincola

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Caloplaca thallincola


Name: Caloplaca thallincola (Wedd.) Du Rietz

Pronunciation: Caloplaca thallincola

Conservation Evaluation: Least Concern

Body Type: Crustose

Description: Caloplaca thallincola is yellow-orange in colour and frequently forms circular or arc-shaped patterns on silica-rich rocks (HS). The fringe of the thallus has a finger-like or placodioid pattern. The finger-like shapes are well defined, long and convex with distinct furrows between them. The thallus is tightly bound or adpressed to the rocks. The central area of the thallus is lumpy or convex areolate. Jam tart-like apothecia normally populate the central area of the thallus. The rim of the apothecia is the same orange colour as the thallus. The disc is a brownish-orange colour and is flat in juvenile apothecia and convex in mature ones. Apothecia are up to 0.8mm diam. The spores are 2 celled, colourless with a thick septum giving a polarilocular effect. This is a distinguishing feature. The species can be confused with Caloplaca flavescens, however the paraphyses are forked towards the tips in C. thallincola only. The photobiont is the green algae Trebouxioid.

Chemical Tests: K+ crimson.

Nature Notes: Caloplaca thallincola is a seashore lichen, found in the mid region orange belt or supra littoral zone in sheltered locations (facing away from direct wave action). It needs exposure to sea salt spray and often grows over the black Verrucaria maura where its bright orange colour becomes even more striking. Some specimens can look rather shabby due to grazing by molluscs such as limpets, whelks and periwinkles. It is frequently found close to populations of Caloplaca flavesens (C. thallincola is brighter). It is rare on limestone, but common on sandstone and shales along the south and south-west coast. In general, it prefers rocks with a high silica content.

Vice County distribution map of Caloplaca thallincola: See Map

Link: Map this species on the Lichen Survey

Other species recorded In Ireland

  • Caloplaca alociza (A.Massal.) Mig.
  • Caloplaca arenaria (Pers.) Müll.Arg.
  • Caloplaca atroflava (Turner) Mong.
  • Caloplaca aurantia (Pers.) Hellb.
  • Caloplaca britannica R.Sant.
  • Caloplaca ceracea J.R.Laundon [3]
  • Caloplaca cerina (Ehrh. ex Hedw.) Th.Fr.
  • Caloplaca cerinella (Nyl.) Flagey
  • Caloplaca chalybaea (Fr.) Müll.Arg.
  • Caloplaca chlorina (Flot.) H.Olivier
  • Caloplaca cirrochroa (Ach.) Th.Fr.
  • Caloplaca citrina (Hoffm.) Th.Fr.
  • Caloplaca concilians (Nyl.) H.Olivier
  • Caloplaca crenularia (With.) J.R.Laundon
  • Caloplaca crenulatella (Nyl.) H.Olivier
  • Caloplaca dalmatica (A.Massal.) H.Olivier
  • Caloplaca decipiens (Arnold) Blomb. & Forssell
  • Caloplaca ferruginea (Huds.) Th.Fr. [4]
  • Caloplaca flavescens (Huds.) J.R.Laundon
  • Caloplaca flavocitrina (Nyl.) H.Olivier [5]
  • Caloplaca flavorubescens (Huds.) J.R.Laundon
  • Caloplaca flavovirescens (Wulfen) Dalla Torre & Sarnth.
  • Caloplaca holocarpa (Hoffm.) A.E.Wade
  • Caloplaca lactea (A.Massal.) Zahlbr.
  • Caloplaca littorea Tav.
  • Caloplaca luteoalba (Turner) Th.Fr.
  • Caloplaca marina (Wedd.) Zahlbr. ex Du Rietz
  • Caloplaca maritima de Lesd.
  • Caloplaca microthallina (Wedd.) Zahlbr.
  • Caloplaca obliterans (Nyl.) Blomb. & Forssell
  • Caloplaca obscurella (Lahm ex Körb.) Th.Fr.
  • Caloplaca ochracea (Schaer.) Flagey
  • Caloplaca polycarpa (A.Massal.) Zahlbr.
  • Caloplaca saxicola (Hoffm.) Nordin [7]
  • Caloplaca teicholyta (Ach.) J.Steiner
  • Caloplaca ulcerosa Coppins & P James
  • Caloplaca variabilis (Pers.) Müll.Arg.
  • Caloplaca verruculifera (Vain.) Zahlbr.

Text and images © Paul Whelan, 2009.