Fig. 5.

Reproduction of the original drawings by Sopp (1912) illustrating Acaulium albonigrescens (original numbers are maintained to indicate the different structures). A. Asexual morph: 40. Germinating conidia. 41–44. Conidiophores, conidiogenous cells and conidia. 45. Synnematal conidiophores. 46–51. Diverse phases of perithecial development, the first stages are seen in 46a and b. B. Sexual morph: 52. Sections of perithecia showing the ostiole development. 53. Horizontal section of perithecia embedded in the mycelium. 54. Mature perithecium. 55. Cross section of an immature perithecium. 56. Cross section of a fully mature perithecium, completely emptied through the ostiole. 57. Cross section of an empty perithecial ostiole. 58. Cross section of a perithecial ostiole during the liberation of ascospores. 59–60. Free ascospore masses. 61. Asci. 62. Ascospores. 63–65. Macroscopic features.