Orbilia flavidorosella Rehm

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 : 237-238

Orbilia flavidorosella Rehm , in Sydow, Hedwigia 33 (Beibl.): 31 (1894). ( Fig. 4 )

Apothecia 0.2–0.7 mm in diam., up to 0.2 mm high, scattered, brownish pink (33. br Pink) to light grayish yellow brown (79. l. gy. y Br), disc concave to flat, not erumpent from substrate, margin distinct, slightly hairy. Asci *44–52.5(62.5) × (3.7)4–4.5 μm, †38–44 × 3.2–3.7 μm; thin apex; cylindric-clavate, 8-spored, spores 2-seriate, with 3–4 lower spores inverted, pars sporifera *16–33 μm; with a short to long bifurcate base. Ascospores *8–9.5(10) × 1.5–1.9 μm, †7–9 × 1.2–1.5 μm; fusoid to fusiform-clavate, straight to slightly curved, with acute to acuminate apex and slightly to medium tapered base, rarely like tail with or without bulbous extreme; SBs *(3.5)4–5 × 0.5–0.7 μm, subulate to vermiform, apically attached by a narrow point. Paraphyses sublageniform to lageniform, 2–3-septate; terminal cell *17–21(22) × 2.6–3.5 μm, cell below *6.8–9 × 1.5–2.8 μm; not branched; exudate over paraphyses lacking or like scarcely granular, with yellow gray (93. y Gray) filiform and trapezoid (1.3–2.4 × 0.3–0.7 μm) SCBs. Ectal excipulum at base and middle flanks of textura angularis to t. globosa, *29–42 μm thick; at margin and upper flank of t. angularis to t. prismatica *20–32 μm thick; hyaline, not gelatinized, without exudate. Cells of ectal excipulum *(10)12–16(18) × (8.3)9.5–12.5(13.5) μm at base and lower flank, wall thickness *0.4–0.8 μm; *(7)8–12(13) × 4–6 μm at margin, cortical cells like hairs (13–22 × 2.2–5 μm), with abundant yellow gray (93. y Gray) filiform, trapezoid and lasso-shaped (3–5 × 2–3.6 μm) SCBs.

Specimens examined:— SPAIN. Canary Islands: Tenerife, 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 bark of Spartocytisus supranubius , 5 November 2012, L. Quijada & C. Quijada (TFC Mic. 23738!). Adeje, Lomo el Dornajito, 28°11’33’’N, 16°40’05’’W, 2081 m, Canary pine woodland with summit brooms, on bark of Spartocytisus supranubius , 9 March 2013, L. Quijada & C. Quijada (TFC Mic. 23925!).

Distribution and ecology:— The species has been reported in the northern hemisphere in Europe ( Germany, Czech Republic). Growing on herbaceous stems of Vincetoxicum . Occurring in spring ( Saccardo 1895, Sydow 1894, Svrček 1955). In Macaronesia, it was found in autumn and spring on xeric branchs of Spartocytisus supranubius , in the transition between pine woodland and summit broom scrubs above 2000 m.

Remarks:— Orbilia flavidorosella was orginally described with asci 45 × 5 μm, straight or slightly curved subfusiform ascospores 7–9 × 2 μm, and filiform paraphyses with a widened apex (Rehm, in Sydow 1894). In 1955, Svrček combined the species in the genus Hyalinia as ‘ H. flavide-roseola ’ and provided a detailed description of the species, including lageniform paraphysis apices. However, Spooner (1987: 196) doubted placement in Hyalinia because the hairs are described as simple, non-glassy, and suggested that the species might belong in Habrostictis . With the exception of slightly narrower spores, our sample fits quite well the literature (where the characteristic spore body was overlooked), and also with the re-examination of the holotype by one of us, which showed the paraphyses to be lanceolate (H.B., Baral et al. in prep.).

Orbilia flavidorosella resembles O. carpoboloides. The latter was recently described and illustrated by Friebes (2011), and differs in ascospore (*8.5–12.3 × 2–2.3 μm) and ascus measurements (*74–83 × 5.5–6.2 μm), both being bigger than in O. flavidorosella .

Figures

FIGURE 4. Morphological features of Orbilia flavidorosella. 1. Rehydrated apothecia. 2. Living excipular tissues in median section. 3. Living asci. 4. Living paraphyses. 5. Living ascospores. 500 μm= 1a; 100 μm= 1b; 50 μm= 2a; 10 μm= 2b–c, 3, 4a–c, 5a–b. Mounted in: CRB= 2b, 4a; H2O= 2a–c, 3, 4b–c, 5a–b. Photos: TFC Mic. 23738= 1a, 2a–b, 3, 4a–c, 5b; TFC Mic. 23925= 1b, 2c, 5a.