Cladonia mollis Ahti & Sipman, 2013

Ahti, Teuvo & Sipman, Harrie J. M., 2013, Ten new species of Cladonia (Cladoniaceae, Lichenized Fungi) from the Guianas and Venezuela, South America, Phytotaxa 93 (1), pp. 25-39 : 30-32

Cladonia mollis Ahti & Sipman , sp. nov. ( Fig. 5)

Mycobank # MB 475357

Thallus primarius laciniatus, viridis. Podetia 1–2(3) cm alta, pallide vel viride flavescentia, semper scyphosa, scyphis 1– 4 mm latis. Superficie fere toto granuloso-sorediata et microsquamulosa, toto vel fere ecorticata. Disci hymeniales coccinei. Acidum usnicum, acidum thamnolicum et acidum rhodocladonicum continens.

Type:— GUYANA. Demerara-Mahaica Region: on Linden Highway, km 7 from Soesdyke, by end of trail to Marudi Creek Resort, 06º31’N, 58º12’W, 10 m elev., on burnt stump in secondary woodland with savanna patches on white sand, 1996, T . Ahti, R. Lücking & H. Sipman 52910 (holotype BRG!, isotypes B!, H!, US!, VEN!) .

Primary thallus squamulose, consisting of green, flattish squamules with convex lobes and necrotic bases turning orange. Podetia 1–2(–3) cm tall, of determinate growth, whitish to greenish yellow, always forming scyphi; scyphi 1–4 mm wide, usually single but with age proliferating from the margins and sometimes forming a second scyphus at the end of the proliferations, just below the short-stalked apothecia. Podetial surface totally ecorticate or little corticate at the very base, otherwise very rough due to coarse granules and often very densely beset with microsquamules, all of which dissolve into a thick layer of loose, finely granulose soredia towards the tops. Podetial wall not measured. Conidiomata formed on margins of young scyphi, typically black, cylindrical, shortly stipitate; with purple slime inside. Hymenial discs unusual, at margins of scyphi, forming 1–2 mm wide purple disks. Chemistry: K+ yellow, PD + yellow, containing usnic and thamnolic acids, as well as the purple pigment rhodocladonic acid in hymenial discs and conidiomata.

Distribution and ecology:— Cladonia mollis is known from the Guianas and northern Brazil, but is expected to be more widespread in Amazonia. It was observed on rotten wood and white sand in forest clearings and savannas, from 10 to 500 m elev.

Additional specimens examined (paratypes):— GUYANA. Demerara-Mahaica Region: type locality, Ahti 52900 (B!, BRG!, H!, US!), 52912 ( BRG!, H!, US!); Cuyuni-Mazaruni Region, Bartica , Linder 810 ( FH!, TUR-V 14099 !, W!, as “ Cladonia Guiana Vain.” in herb.); Potaro-Siparuni Region , Kaieteur Falls National Park , DePriest 9316 ( BRG!, H!, US!); Tukeit , DePriest 9361 ( BRG!, H!, US!); Basin of Essequibo R., Kurupukari, A.C. Smith 2178 (NY!); Upper Demerara-Berbice Region, Mabura Hill, along logging road WS 1200, Waraputa compartment, DePriest 9179 ( BRG!, H!, US!); Upper Mazaruni Region, Makwaima savanna near Mayaropai, at Kako R., wet savanna on white sand, Sipman & Aptroot 18538 (H!, L!) . FRENCH GUIANA. Inselberg de Montagne de la Trinité , NE summit, on dead wood in rock savanna, de Granville et al. 6252 (B!, L!) . SURINAME. No locality, [1827–28] C. Weigelt in Herb. Schweinitz (PH!); Sabanpasi savanna complex, Nature Reserve Brinckheuvel , summit of Brinckheuvel , on coarse, white sand, Teunissen & Wildschut LBB 11933 (H!, L!); Jodensavanne , Benjamins (L!), Stahel (L!, REN!) . BRAZIL. Amazonas: Manaus-Itacoatiara road km 18, under 100 m elev., in secondary campina forest, Richards 6949 ( BM!) ; Pará: Serra do Cachimbo, Base Aérea do Cachimbo , ca. 20 km N of the border with Mato Grosso on Cuiabá- Santarém highway (RB-163), ca. 09º 22’S, 54º 54’W, broad, sandy, level riverine plain, Brako & Dibben 5810 (H!, INPA, NY!) .

Remarks:— The species is distinguished from the very similar C. corallifera ( Kunze 1827 -1828) Nylander (1874: 70) by the production of distinct soredia almost throughout the surface of the podetia. However, it may be difficult to distinguish from granulose morphs of C. corallifera . In Guiana we encountered the two species growing together in some places, where they appeared to be distinct. Also E. A. Vainio recognized the species under an unpublished herbarium name (see above). All the specimens of C. mollis that were chemically studied contained thamnolic acid, while in C. corallifera the chemistry is more variable (Ahti 2000).

Cladonia mollis is also closely related to C. prancei Ahti (2000: 223) , another sorediate derivative of C. corallifera , which in addition has podetia forming narrow scyphi, sometimes becoming subulate, with a low content of usnic acid often giving the podetia a pale grey colour without yellowish tinge.

Sorediate squamules have been found only in the specimen Sipman & Aptroot 18538.