Trimmatothelopsis californica K. Knudsen, Dart, Kocourk. & Hodkova, 2023

Knudsen, Kerry, Kocourkova, Jana, Hodkova, Eva, Dart, Jason, Huereca, Alejandro & Malicek, Jiri, 2023, Three new species of Trimmatothelopsis (Acarosporales, Acarosporaceae) from southwestern North America, MycoKeys 99, pp. 251-268 : 251

Trimmatothelopsis californica K. Knudsen, Dart, Kocourk. & Hodkova sp. nov.

Fig. 2

Type.

U.S.A. Monterey Co.: Cholame Hills , along Cholame Creek, annual grassland, 35.8318; -120.3573, alt. 390 m, on granite, 12 Feb. 2016, Jason Dart 577 (holotype-BYU-C, isotype-OBI) .

Diagnosis.

Similar to Trimmatothelopsis oreophila but differing in having regularly elevated apothecia mostly 0.5 mm wide in a dark brown crown, in having areoles with an elevated mycelial base instead of being squamulose with a stipe, and in having short conidia (1.8-)2.0-2.26-2.5(-2.8) × (0.8-)0.82-0.98-1.1(-1.3) µm, l/b 2.3.

Etymology.

The name refers to the region in which the species occurs.

Description.

Thallus of dispersed or contiguous bullate to irregular areoles, 0.5-1.0 mm wide and ca 0.4 mm high, replicating by division, forming clusters up to 5 mm wide and 1.5 mm high, broadly attached, but subsquamulose with lobes and becoming elevated on a mycelial base. Upper surface epruinose, light or dark brown to reddish brown, smooth or rough, glossy or dull. Lower surface of lobes white. Epicortex 10-25 µm thick. Cortex 40-60 µm thick, of disarticulated hyphae, mostly cells 3-4 µm, upper layer one cell thick, ends of hyphae in brown pigment caps 5-7 µm wide. Algal layer continuous, 60-100 µm thick, some hyphal bundles interrupting the algal layer but may not be seen in every section, algal cells not dense, the lower layer tending to be uneven, extending below apothecia, algal cells mostly 5-12 µm. Medulla obscured with crystals and gelatinization, hyphae intricate 3-5 µm wide. Apothecia usually 1-6 per areole, 0.2-0.6 mm wide, disc black, rough, epruinose. Margin elevated, slightly higher than the disc, color of thallus. Parathecium 40-70 µm wide, hyphae thin 1.4-2.0 µm wide, IKI-, merging with cortex and pushing it up to form the margin. Hymenium 110-170 µm high, epihymenium 15-20 µm thick, light brown, paraphyses 1.5-2.0 µm wide, apices unexpanded, equator up to 400 µm wide, hymenial gel IKI+ hemiamyloid, blue turning red. Asci 90-140 × 15-22 µm, Acarospora -type ascus stain, ascospores (4-)4.5-5.13-5.8(-6.2) × (2.1-)2.3-2.45-2.6(-2.8) µm (n = 20), l/b 2.1. Subhymenium 30-50 µm thick, IKI+ blue, euamyloid. Hypothecium 10-17 µm thick, IKI-. Pycnidia 165-244 × 77-140 µm, multi-chambered, conidiogenous cells 6-14 × 1.5-3.0 µm, conidia (1.8)-2.0-2.26-2.5(-2.8) × (0.8-)0.82-0.98-1.1(-1.3) µm (n = 20), l/b 2.3.

Habitat and distribution.

Trimmatothelopsis californica is so far only known from California. It occurs from sea level to 2330 m on granite, volcanic rock, and schist, in central and south California (Monterey Co., Santa Cruz Island, Santa Monica Mountains, San Bernardino Mountains, San Jacinto Mountains).

Additional specimens examined.

U.S.A. California: Los Angeles Co., Santa Monica Mountains, Malibu State Park , Lost Cabin Trail , 34.0933, -118.7405, alt. 240 m, on volcanic rock, 10 Aug. 2009, K. Knudsen 11731 & T. Sagar (SBBG), Riverside, San Jacinto Mountains , Cedar Springs Trail, southwest-facing slope, 33.6644, -116.5766, alt. 1890 m, on schist in underhang, 13 Aug. 2005, K. Knudsen 3493 (NY, SBBG), Devil’s Slide, sunny open area on west-facing slope, 33.7752, -116.6780, alt. 2330 m, on granite with Aspicilia species, 15 Sept. 2006, K. Knudsen 7194 (SBBG), near trail to Round Valley , 33.8075, -116.6522, alt. 2670 m, frequent on granite, 17 Nov. 2006, K. Knudsen 7889 (SBBG); San Bernardino Co. , San Bernardino Mountains , pebble plain along Polique Canyon Road, 34.305, -116.85083, alt. 2280 m, on small granite pebbles, 25 Aug. 2010, K. Knudsen 13676.1 & S. Eliason (SBBG); Santa Barbara Co. , Santa Cruz Island , High Mount, 34.0314, -119.5824, alt. 410 m, on volcanic rock, 19 July 2012, K. Knudsen 14985 & J. Kocourková (SBBG); Ventura Co. , Santa Monica Mountains , Point Mugu State Park , base cliffs above normal high tide level, 34.0986, -119.0763, 3 m, on volcanic rock, 10 Oct. 2005, K. Knudsen 4067.2 & M. Knudsen (SBBG) .

Notes.

Trimmatothelopsis californica differs from other species in the genus in having short conidia. It can easily be confused with Acarospora elevata H. Magn., a species often on granite at high elevations from California to the Rockies ( Knudsen 2007). Acarospora elevata has an elevated parathecial crown but has usually a lower hymenium than T. californica (ca 60-120 µm) as well as dark blue euamyloid hymenial gel vs. IKI+ hemiamyloid hymenial gel.

Specimens of Trimmatothelopsis can be misidentified as Myriospora . Myriospora differs in having shorter conidia usually less 3 µm long. Both are well-supported as separate genera (Fig. 1 ; Westberg et al. 2011; Knudsen et al. 2021c). Because of the height of hymenium and a poor understanding of Myriospora taxonomy at that time in North American lichenology, T. californica was identified as Acarospora scabrida Hedl. ex H. Magn. ( Knudsen 2005, 2007). The circumscription of A. scabrida is heterogenous in Knudsen (2007). We do not recognize Myriospora scabrida (Hedl. ex H. Magn.) K. Knudsen & L. Arcadia as occurring in California.

Figures

Figure 1. Bayesian inference tree obtained by phylogenetic analysis using a combined data set of ITS, mtSSU and nLSU sequences of 27 members of Acarosporaceae. Bayesian posterior probability (BPP ≥ 0.95) and maximum likelihood bootstrap values (ML ≥ 70 %) are indicated above branches (BPP / ML). Pycnora sorophora was used as outgroup. In bold are species with IKI + blue asci. The remaining species of Trimmathelopsis not in bold have IKI- asci.

Figure 2. Trimmatothelopsis californica, Jason Dart 577, Holotype A areolate thallus with apothecia B thallus areoles with pycnidia C vertical section of apothecium D apothecial crown E hemiamyloid reaction of hymenium and amyloid reaction of subhymenium and bleeding into hypothecium turning it a lighter blue F young ascus G young ascus in IKI H paraphyses in IKI I cortex above interrupted algal layer J mostly biguttulate ascospores K vertical section of the thallus with pycnidia L hyphal tissue below pycnidium M long ampulliform conidiogenous cells producing conidia N mass of conidia in pycnidial gel. Scale bars: 500 µm (A, B); 100 µm (C); 50 µm (D, E, K); 20 µm (F-I, L); 10 µm (M); 5 µm (J, N).