Pyrenomycetes Species Page

Lasiosphaeria ovina

Large separate ascomata
Phragmospore
(Pers.) Ces. & De Not., Comm. Soc. crittog. Ital. 1(4): 229 (1863)
Sphaeria ovina Pers., Syn. meth. fung. (Göttingen) (1801)
Sordariomycetidae
Sordariales, Lasiosphaeriaceae
Figure from multiple collections Type Specimen: SWITZERLAND (possibly). Hb. Pers., 910.269-84, L10261 No. 12 (as Sphaeria ovina Pers., L)
Genbank Accession: NG_013196 (SSU), AY436413 (LSU), AY587923 (ITS), AY600263 (Btub), AY600284 (RPB2)
Complete Description
Ascomata ampulliform to ovoid, rarely obpyriform, papillate, 360–620 µm diam, 380–680 µm high, numerous, scattered to gregarious, superficial; young ascomata tomentose, white, tomentum becoming tightly appressed, crust-like and cream to brownish-gray with age, occasionally areolate, tomentum then partially wearing away and forming a thin, waxy, grayish coating, finally tomentum completely worn away and ascomata appearing glabrous and black; neck conical, glabrous, black. – Ascomatal wall of textura angularis in surface view, commonly containing globular, refractive crystals in squash mounts, in longitudinal section 3-layered, 42.5–86 µm thick, inner layer pseudoparenchymatous, 8–9.5 µm thick, composed of 4–6 layers of elongate, flattened, hyaline to pale brown cells, middle layer pseudoparenchymatous, 16.5–35 µm thick, composed of 5–8 layers of polygonal to angular, pale brown cells, outer layer prosenchymatous, 18–41.5 µm thick, composed of several to few layers of hyphae depending on age of ascomata, hyphae 1–3 µm wide, hyaline to pale brown, septate, thin-walled. – Ascomatal apex with periphyses. – Centrum with yellow to yellowish-orange or rarely greenish-yellow pigments which quickly diffuse in water. – Paraphyses filiform, 1.5–5.5 µm wide, longer than asci, hyaline, numerous, septate, unbranched, persistent, contents rarely containing blue pigments in fresh specimens only. – Asci cylindrical, 140–250 X 12–23 µm, medium- to long-stipitate, stipe 30–85 (–120) X 3–6.5 µm, numerous, unitunicate, thin-walled, apex truncate; ring narrow, shallow, refractive; subapical globule large, 3.5–6 µm diam, smooth to verrucose, with 8, biseriate to tetraseriate ascospores. – Ascospores cylindrical, ends rounded, 35–55 (–60.5) X 3–6 µm [45.5 ± 4.5 X 4.5 ± 0.5], straight when first produced, hyaline, aseptate, bipolar appendages occasionally present, 5.5–12 µm, gelantinous, spike-like or awl-like, evanescent; becoming slightly sigmoid or geniculate, lower 1/3 to 1/4 bent 45° or less, appendages rarely present at this stage; after liberation from the ascus up to 7-septate or rarely 9-septate, each cell with a single globose, refractive oil droplet; finally becoming yellowish, yellowish-brown or pale brown with age, sometimes constricted at clamps and appearing worm-like, occasionally producing phialides directly from the ascospore. Colonies on WA moderately slow-growing, 21–40 mm diam in 21 d, moderately fast-growing on CMA and PDA, covering the CMA plate in 21 d and the PDA plate in 28 d, silky on WA and CMA, wooly on PDA, becoming hispid with long, erect, white hairs composed of agglutinated, thin-walled hyphae, mat appressed on WA and CMA, appressed to aerial on PDA, hyaline on all media, becoming whitish to grayish-yellow (4A1–4B4) on PDA; margin even in all media, appressed, hyaline; reverse same as the mat in all media; anamorph produced abundantly over entire mat on WA and CMA and sparsely at the margin on PDA within 14 d. Hyphae largely undifferentiated, 1–4 µm wide, thin-walled, hyaline. – Conidiogenous cells phialides, produced laterally or occasionally terminally, delimited by a basal septum, monophialidic or sometimes polyphialidic, obclavate to lageniform, 6.5–16.5 X 2.5–3.5 µm at widest part, hyaline to pale brown, constricted below the collarette, 0.5–1.5 µm below collarette; collarette minute, flaring, same color as phialide. – Conidia pyriform, truncate at base, 3–4 X 2–3 µm, hyaline, produced enteroblastically, aggregated in slimy heads; slightly larger blastoconidia also commonly produced directly from hyphae or branches, branches produced laterally, not delimited by a basal septum, extremely short to long, cylindrical, 1.5–24 X 1–3 µm at widest part, hyaline, collarette-less; blastoconidia subglobose to pyriform or occasionally obclavate, 3–4.5 (–6) X 2.5–3.5 µm, hyaline. (from Miller and Huhndorf 2004)
Occurrence
Found on dead, decorticated deciduous trees throughout the world including Canada, Costa Rica (as L. chrysentera Carroll & Munk), Denmark, England, France, Germany, New Zealand, Philippines, Russia, Switzerland, and USA.
Similar Taxa Comments
Lasiosphaeria ovina is recognized by its white, tomentose ascomata, asci with globose subapical globules, and ascospores which do not develop a swollen head at maturity and usually possess short, awl-like appendages in their early stage.
Reference
Miller, A.N. and S.M. Huhndorf. 2004. Using phylogenetic species recognition to delimit species boundaries and species relationships within Lasiosphaeria. Mycologia 96(5): 1106–1127.