Orbilia gambelii Baral & G. Marson

Quijada, Luis, Baral, Hans-Otto & Beltrán-Tejera, Esperanza, 2016, A revision of the genus Orbilia in the Canary Islands, Phytotaxa 284 (4), pp. 231-262 : 256

Orbilia gambelii Baral & G. Marson , in Karasch, Dämon, Jaklitsch & Baral, Öst. Z. Pilzk. 14: 286 (2005) ( Fig. 14 )

Apothecia 0.3–0.5 mm in diam., 0.1–0.2 mm high, scattered to gregarious, light orange (52. l. O) to medium orange (53. m. O), superficial, disc flat, margin smooth. Asci *(46.5)50–53(60) × (4.6)5–5.7 μm, †(39)44–50(54.5) × 3.5–5 μm; apex thin walled; cylindric-clavate, 8-spored, spores 1-seriate, with (1)3–4 lower spores inverted (sometimes mixed), pars sporifera *24–32.5 μm; with a long medium bifurcate base. Ascospores *5.2–6.5 × 2.2–3 μm, †4.3–6 × 2–2.5 μm; ellipsoid to obovoid (rarely fusoid), straight to inequilateral, apex obtuse to (sub)acute, base rounded to obtuse; SBs *(3.6)4–4.7(5.5) × 0.3–0.8 μm, filiform to subulate, strongly flexuose to curled. Paraphyses strongly clavate to capitate, 2–3-septate; terminal cell *(9)11.5–14(16) × (3.5)4–4.7(5.5) μm, cell below *(8.5)10.3–12.5(15.5) × 1.2–2 μm; not branched; exudate 0.2–1 μm thick, light yellow (86. l. Y), continuous and closely attached; light gray (264. l. Gray) globose SCBs usually present in apical cell, 0.8–1.6 μm diam., trapezoid SCBs present in cell bellow. Ectal excipulum at base and middle flanks of textura angularis to t. globosa, *40–76 μm thick; at margin and upper flank of t. angularis, *13–38 μm; hyaline, not gelatinized, without or with a thin and loosely attached, deep yellow (85. deep Y) layer of exudate at margin. Cells of ectal excipulum *(7.5)10–11.5(17) × (5.2)7.7–9(12) μm at base and lower flank, wall thickness *0.3–0.9 μm; *(5)7–8(11) × (3)4.7–5.5(7) μm at margin, with grayish yellow (90. gy. Y) annular SCBs 2–4 × 2–3.6 μm.

Specimens examined:— SPAIN. Canary Islands: Tenerife, La Laguna, Anaga Rural Park, Andén de la Cruz, 28°34’03’’N, 16°18’06’’W, 337 m, Euphorbia canariensis scrub, on Echium leucophaeum , 29 Dec 2013, L. Quijada & E. Rodríguez (TFC Mic. 24443!). Idem, on Rubia fruticosa , 29 Dec 2013, L. Quijada & E. Rodríguez (TFC Mic. 24447!). La Orotava, Teide National Park, Cañada de la Mareta, 28°13’36’’N, 16°36’43’’W, 2190 m, meso-oromediterranean summit broom scrub on Carlina xeranthemoides , 5 Nov 2012, L. Quijada & C. Quijada (TFC Mic. 23751!). Idem, Cuesta la Burra, 28°18’08’’N, 16°34’27’’W, 2075 m, meso-oromediterranean summit broom scrub, on wood of a detached branch of Adenocarpus viscosus , 30 Dec 2013, L. Quijada & C. Quijada (TFC Mic. 24371!).

Distribution and ecology:— The species has been reported in the northern hemisphere in the Canary Islands (La Palma), Europa [ Spain (Guadalajara), France], and North America. Growing in mediterranean regions on xeric wood and bark of various angiosperms (e.g., Chamaecytisus , Jasminum ). Occurring throughout the season, from autumn to summer (GBIF, Karasch et al. 2005).

Remarks:— All morphological characters fit well the original description ( Karasch et al. 2005), although the scope of ascospore length is wider than ours (*4.5–9 μm vs. *5.2–6.5 μm). In the protologue the species was only briefly described, and a full account will be found in the monograph (Baral et al. in prep.).

There exist some further unpublished species that resemble Orbilia gambelii . They differ either in having 16- spored asci, or if they have the same number of ascospores, they do not possess annular soluble cytoplasmic bodies, or differ in narrower or shorter ascospores (Baral et al. in prep.).

Figures

FIGURE 14. Morphological features of Orbilia gambelii. 1. Fresh apothecia. 2. Excipular tissues in median section.3.Asci. 4.Ascospores.