Acarospora aquatica K. Knudsen, Kocourk. & Kondrysová, 2025

Acarospora aquatica K. Knudsen, Kocourk. & Kondrysová sp. nov.

Fig. 3 View Figure 3

Type.

U. S. A. • New York. Rockland Co., Harriman State Park, between Conklin Mountain and Wanaksink Lake, vicinity of Tuxedo Rock , 41.1883, -74.1247, alt. 366 m, on quartz crystals on granite dome between Sphagnum depressions, 9 March 2008, J. C. Lendemer 11525 (NY-holotype) GoogleMaps .

Diagnosis.

Differing from Sarcogyne cyclocarpa in having a wetlands ecology and forming compound apothecial structures by replication through division.

Etymology.

Named for its occurrence in swamps and wetlands, an unusual character in the family.

Description.

Thallus endolithic, algal layer usually visible at base of apothecia, algal cells 5–10 µm wide, often forming continuous layer below compound apothecia. Apothecia dispersed, becoming compound, ca. 0.2–0.4 mm wide, 0.2–0.3 mm thick, including the stipe, lower surface carbonized. Margin ca. 50 μm wide, outer layer carbonized, inner layer hyaline to light brownish color, widths variable, sometimes gobs of melanin build-up on the outer surface. Disc black with umbos and / or gyrose structures. Hymenium 100–125 µm tall, paraphyses 1–2 µm wide, apices barely expanded, hymenial gel IKI + blue to red, hemiamyloid. Asci 60–80 × 10–20 µm, ascospores 4–5 × 2 μm. Subhymenium 40–80 µm tall, IKI + blue. Hypothecium usually indistinct, continuous with endolithic thallus and margin of solitary apothecia or outer wall of compound apothecia. Pycnidia not observed. Not producing secondary metabolites.

Habitat and distribution.

On granite or quartz in granite, limestone, and Altamaha grit sandstone in wetlands in Connecticut, Georgia, New York, and West Virginia.

Additional specimens examined.

U. S. A. • Connecticut, Windham Co., Eastford, Natchaug State Park, Cat Den Swamp, red maple swamp, along Fayette Road , 41.8431, -72.0547, no alt., on granite, 19 Sept. 2009, R. C. Harris 55703 ( NY) GoogleMaps ; • Georgia, Coffee Co., Broxton. Broxton Rocks TNC Preserve, High Point Outcrop. loblolly pine, water and blackjack oaks , 31.7422, -82.8536, no alt., on Altamaha grit sandstone; 10 Jul. 2007, E. Lay s. n. ( NY) GoogleMaps ; • New York, Jefferson Co., Three Mile Creek Barrens, hardwood swamp forest , 44.13, - 76.1525. no alt, on adjacent alvar limestone pavements, 25 May 1997, R. C. Harris 40852 ( NY) ; • West Virgina, Tuckerco Co., Blackwater Falls State Park, open fields and wetlands 39.1158, -79.4808, alt. 945 m, on rock, 23 Apr. 2001, R. C. Harris 44925 ( NY) GoogleMaps .

Notes.

The species is probably occasionally submerged.

We first studied all specimens at NYBG in 2011 and published them as Polysporina cyclocarpa ( Knudsen et al. 2011) . We did limited dissection of specimens in 2023 and 2024 at BYU to preserve specimens. We base ascospore data on our previous study ( Knudsen et al. 2011). All the specimens were old, and sequences were only recovered from the holotype.