Sticta riparia Merc.- Diaz

Ossowska, Emilia Anna, Moncada, Bibiana, Luecking, Robert, Flakus, Adam, Rodriguez-Flakus, Pamela, Olszewska, Sandra & Kukwa, Martin, 2024, Additional new species and new records of the genus Sticta (lichenised Ascomycota, lobarioid Peltigeraceae) from Bolivia, MycoKeys 105, pp. 21-47 : 21

Sticta riparia Merc.- Diaz

Fig. 7

Description.

For the description, see Mercado-Díaz et al. (2020).

Habitat and distribution.

The record of S. riparia presented here is the first one from Bolivia and South America, as the species has been previously known only from Puerto Rico ( Mercado-Díaz et al. 2020). In Bolivia, the species was found on tree bark in semi-natural Sub-Andean Amazon forest in the Cochabamba Department.

Notes.

Sticta riparia has a strongly branched thallus, with undulate lobes, the margins of which are covered with branched, abundant, palmate, grey to dark brown phyllidia. The lower surface is greyish-brown, with the primary tomentum absent towards the margins. In addition, cyphellae are abundant, with a density of 41-60 per cm2 towards the centre and more than 100 per cm2 towards the margins ( Mercado-Díaz et al. 2020). It is similar to S. densiphyllidiata as, in both species, the lobe margins are abundantly covered by phyllidia, but in S. densiphyllidiata , these are dispersed, coralloid and darker than the thallus. Furthermore, the lower surface of the latter taxon is reddish with a dense tomentum. The abundance of the cyphellae towards the margins and centre is also a feature common to both taxa. However, in S. densiphyllidiata , the membrane reacts with K+ weakly pink, whereas in S. riparia , it is K+ pale yellow ( Mercado-Díaz et al. 2020). Both species belong to clade III of the Sticta tree (Fig. 1 ). Sticta densiphyllidiata is only known from Puerto Rico ( Mercado-Díaz et al. 2020).

Recently, a new phyllidiate species, S. cerradensis T.D. Barbosa, J.-M. Torres, Kitaura & A.P. Loren, phylogenetically similar to S. riparia , has been described. However, it has larger lobes and the lower surface is light brown to dark. Sticta cerradensis is only known from Brazil ( Torres et al. 2021).

Specimens examined.

Bolivia. Dept. Cochabamba; Prov. Chaparre, Parque Nacional Carrasco, Guacharos, 17°03'50"S, 65°28'31"W, elev. 445 m, semi-natural Sub-Andean Amazon forest , corticolous, 10 Nov 2016, M. Kukwa 18724 (LPB, UGDA) .

Figures

Figure 1. Best-scoring Maximum Likelihood tree of the Sticta target clade containing the new species from Bolivia (red) and the species new to Bolivia and phylogenetically confirmed from Bolivia (blue), based on the fungal ITS barcoding marker. Supported clades are thickened. For complete tree with individual support values, see Suppl. material 2.

Figure 7. Morphology of Sticta riparia (Kukwa 18724) A upper surface B lower surface with very sparse tomentum C, D marginal phyllidia. Scale bars: 1 mm.