Asterinaceae Hansf., Mycol. Pap. 15: 188 (1946)
= Lembosiaceae Höhn., Annls mycol. 16(1/2): 146 (1918)

Epiphytes obligately biotrophic on the upper or lower surface of leaves, rarely on stalks or shoots of plants, often forming web-like circular structures containing superficial back thyriothecia. Superficial hyphae usually with appressoria, which later form haustoria to obtain nutrients from host. Sexual states: Thyriothecia superficial, forming below or sometimes lateral on surface of hyphae, blackened mycelia, flattened, roundish in outline, elongate or linear, opening by radiating star-like or longitudinal splits, interascal tissue usually absent in mature specimens. Upper wall comprising rows of cells, radiating from the central ostiole to the periphery, base poorly developed. Asci 8-spored, bitunicate, fissitunicate, globose or broadly saccate, usually lacking pedicel, sometimes with a short indistinct pedicel, usually with a thick hyaline apical region, lacking a distinct ocular chamber. Ascospores 2–5 seriate or fasciculate, conglobate, ellipsoidal, occasionally cylindrical, hyaline or brown, mostly 1-septate, mostly brown when mature, wall smooth or roughened. Asexual states: coelomycetous states with pycnidia or pycnothyria and hyphomycetous states without conidiomata or sporodochia then gelatinous, pale. Hyphae brown, superficial,
with appressoria. Conidiomata pycnothyria, flattened, dimidiate, radiate, orbicular, stellately dehisced at the centre. Conidiophores branched or unbranched, hyaline or brown. Conidiogenous cells monoblastic or percurrent, hyaline or brown. Conidia brown, ovate, pyriform, angular, or wall straight to sinuate (Hofmann et al. 2010; Hyde et al. 2013).

Type: Asterina Lév. (1845)

Notes: The Asterinaceae is a family of small, obligately biotrophic ascomycetes that are associated with living leaves
of a broad range of plants from tropical and subtropical regions (Kirk et al. 2001; Barr and Huhndorf 2001; Taylor
et al. 2005; Hofmann et al. 2010; Hyde et al. 2013). The important features of Asterinaceae are the superficial, black,
web-like colonies that form on the upper and lower surface of leaves, and hyphae with appressoria, forming haustoria that infect host tissue. The thyriothecia are closely attached to the host plant cuticle and comprise the scutellum, an upper dark wall, which is one cell layer thick and composed of radiating cells. The thyriothecia form below or sometimes lateral on surface of hyphae and have a concentrically ridged surface— albeit hard to observe under the light microscope (Eriksson 1981). The thyriothecia open at maturity with central star-like fissures, or with lateral slits (von Arx and Müller 1975; Kirk et al. 2001). The interascal hamathecium or pseudoparaphyses are often inconspicuous, deliquesce early, or are lacking (Hofmann et al. 2010). The globose bitunicate asci develop vertically in the thyriothecial cavity, positioned from the base to the dehiscent opening; this is the important character of the
family Asterinaceae which is different from the family Microthyriaceae, where asci grow horizontally to the host
surface and lie horizontally from the thyriothecia rim towards the central rounded ostiole. Ascospores are mostly conglobose, 2-celled, hyaline when young and become brown at maturity. The significance of the J+ascal coating as mentioned by Eriksson (1981) is unclear as we have never observed this.

Key to genera of Asterinaceae

1. Thyriothecia superficial, easily removed from the host
surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
1. Thyriothecia superficial to erumpent, not easily removed
fromthe host surface . . . . . . . . . . . . . . . . . . . . . . . Asterotexis
2.Outline of thyriothecia circular to subcircular . . . . . . . . . 3
2. Thyriothecia elongated or longitudinal with X- or Y-shape
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3. Thyriothecia with hyphae of different lengths at the
margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
3.Thyriotheciawith a neatmargin . . . . . . . . . . . . . . . . . . . . . . . 5
4. Thyriothecia opening with star-like fissures, or centre
ostiole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
4. Thyriothecium widely opening with irregular fissures
whenwet . . . . . . . . . . . . . . . . . . . . . . . . . . Parasterinopsis

5. Hyphae without appressoria, strongly constricted and dark
at the septa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vizellopsis
5. Hyphae with appressoria, not constricted at septa . . Meliolaster
6.Hyphaewithout setae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.Hyphaewith setae . . . . . . . . . . . . . . . . . . . . . Trichasterina
7.Hyphaewith appressoria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.Hyphaewithout appressoria . . . . . . . . . . . . . . . . . . . . . . . . . 13
8.Pseudoparaphyses present . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.Pseudoparaphyses not observed . . . . . . . . . . . . . . . . . . . 10
9. Acospores brown, 3-septate, with smaller ends
cells . . . . . . . . . . . . . . . . . . . . . . . Batistinula
9. Ascospores light-brown to hyaline, 1-septate, upper
cell with rough walls, lower cell with smoothwalled.
. . . . . . . . . . . . . . . . . . . . . . . Asterinella

10. Ascospores 1-septate, rough-walled . . . Trichopeltospora
10. Ascospores 1-septate, slightly smooth-walled . . . . . . 11
11. Ascospores ellipsoid to oval, 2–3-seriate in globose to
subglobose asci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
11. Apiosporous, uniseriate in clavate to cylindrical
asci . . . . . . . . . . . . . . . . . . . . . . . Platypeltella
12. Ascospores hyaline to brown . . . . . . . . . . . . . . . Asterina
12. Ascospores light brown to reddish . . . . . . . Prillieuxina
13. Asciwith ocular chamber . . . . . . . . . . . . . . . . . Schenckiella
13. Asci without ocular chamber . . . . . . . . . . . . . . . . . . . . . . . 14
14. Ascospores fusiform, 3–5 septate . . . . . . . . . . Halbania
14. Ascospores slightly curved, elongate or fusoid, 1-
septate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uleothyrium
15. Hyphaewith appressoria . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
15. Hyphae lacking appressoria . . . . . . . . . . . . . . Echidnodella
16. Hyphae with intercalary appressoria . . . . . . . . . Cirsosia
16. Hyphaewith lateral,mostly conical appressoria . . Lembosia