Plectania lutea T.Bau & G.F.MOU, 2021

Mou, Guang-Fu & Bau, Tolgor, 2021, Plectania lutea (Sarcosomataceae), a new species from southwestern karst areas of China, Phytotaxa 509 (3), pp. 281-290 : 283-288

Plectania lutea T.Bau & G.F.MOU , sp. nov. ( Figure 3–6 )

Mycobank No:—FN570846

Diagnosis:—Ascomata cupulate, with short stalk. Hymenial light yellow when fresh, orange to deep orange when dry. Receptaculum with brown tomentum and vein-like ridges on surface. Medullary excipulum gelatinous, but not semifluid, of textura intricata. Ascospores very finely warted under light microscope (100×), warted under SEM, (24.5)27.0–30.0(32.0) × (12.2)13.0–15.0(16.0) μm.

a. Section of apothecium; b. Medullary excipulum; c. External hairs; d. Moniliform hair-like cells; e. Ectal excipulum.

Scale bar a=300μm; b=20μm; c, d, e=10μm. a. in pure water, b-e in 1% Congo Red solution. From Holotype. Photos by Guang-fu Mou

Etymology:—from Latin “ luteus, luteă , luteum ”, referring to its yellow hymenium when fresh. Type:— China, Guangxi Zhuang Autonomous Region, Hechi city, Mulun National Nature Reserve, 25˚3′14.90″

N, 107˚58′9.45″ E, elevation 497m., 22 April 2020, Guang-fu Mou HMJAU57091 (Holotype HMJAU!; isotype IBK!) .

GenBank from Holotype: ITS= MW 794210 ; LSU = MW 794212 .

a – c: Asci; e–h: Paraphyses; d, i–k: Ascospores.

Scale bar a–c=20μm; e–h=5μm; d=15μm; i–k=10μm.

a–c, e–k in 1% Congo Red solution, d in Melzer’s reagent (IKI). From Holotype. Photos by Guang-fu Mou

Description:—Ascomata 11.0–18.0 mm in diameter, cupulate, 3–5 mm in deep, with short stalk, 2–5 × 1.5–2 mm. Hymenium surface smooth, light yellow (4A4-4A5) when fresh, orange (5A7) to deep orange (5A8) when dry, margin with brown (6D8) tomentum ( FIG. 3 a–d ). Receptaculum brownish orange (6C7-6C8) or light brown to brown (6D6-6D7) when fresh, brown (6E8) when dry, with brown (6D8) tomentum and vein-like ridges on surface ( FIG. 3 b ). Medullary excipulum gelatinous but not semifluid, of textura intricata, 600–1000 μm thick ( FIG. 3 c , FIG. 4 a–b ). Ectal excipulum of textura angularis ( FIG. 4 e ), 20–30 μm thick, near the margin arranged in separable moniliform hair-like cells ( FIG. 4 d ). True hairs arising from outer cells of ectal excipulum, cylindrical, smooth-walled, septate, brown, 4.3–5 μm wide, with obtuse end ( FIG. 4 c ).

Asci 310–370 × 17.5–23.8 μm, cylindrical, 8-spored, rarely with 7 spores, thick-walled, inamyloid ( FIG. 5 a–d ). Paraphyses filiform, septate, branched, slightly enlarged or narrowed near apex, 2–3 × 350–450 μm ( FIG. 5 e–h ). Hymenial hairs (of Sarcosomataceae ) not found. Ascospores ellipsoid, equilateral, hyaline, very finely warted under light microscope (100×, FIG. 5 i–k ), warted under scanning electron microscope ( FIG. 6 a–d ), with 1–2 guttules, (24.5)27.0–30.0(32.0) × (12.2)13.0–15.0(16.0) μm, Q= (1.7)1.9–2.2(2.3), Qav=2.0.

Habitat: Lignicolous, growing on fallen angiosperm twigs.

Known distribution: so far known from Guangxi ( CHINA) only.

Additional material examined:— CHINA. Guangxi Zhuang Autonomous Region, Hechi city, Mulun National Nature Reserve , 25˚03′14.86″N, 107˚58′09.25″ E, elevation 501m., 22 April 2020, Guang-fu Mou, IBKM01 ( IBK!). GenBank from IBKM01 : ITS= MW 794211 ; LSU = MW 794213 .

Figures

FIGURE 3. Ascocarps of Plectania lutea. Scale bar a, d = 20 mm; b, c=10 mm. a–d from HMJAU57091 (Holotype!). Photos by Guang-fu Mou

FIGURE 4. Features of Plectania lutea.

FIGURE 5. Features of Plectania lutea.

FIGURE 6. SEM features of Ascospores. Scale bar a–d=2μm. From Holotype.