(Durieu & Mont.) Kohlm., 1963. Nova Hedwigia, 6: 9.


Dothideomycetes, Subclass Pleosporomycetidae






Halotthia Kohlm., Nova Hedwigia 6: 9 (1963)

Type species:

Halotthia posidoniae (Durieu & Mont.) Kohlm., 1963. Nova Hedwigia, 6: 9.

Index Fungorum number:                           Faceoffungi number:

Sexual morph: saprobic/parasitic stromata: 55-110 µm thick, black, sub-epidermal in cortex of the foliated rhizome of the host. Ascomata: 770-1075 µm high, 1.5-2.1 µm in diam., broadly conical or semi-globose, flattened at the base, enclosed in a stroma, at first immersed, then erumpent, ostiolate, epapillate, carbonaceous, thick-walled, black, solitary, gregarious or confluent. Peridium: 230-285 µm thick at the top. 165-275 µm thick in the sides, plectenchymatous, enclosing cells of the host. Necks: absent, ostiole 110-140 µm in diam. toward the outside; canal obconical, 90-110 µm in diam. near the cavity, filled with tips of entwined pseudoparaphyses. Pseudoparaphyses: 1.5-2 µm in diam., septate, numerous, persistent, ramose. Asci: 275-290 x 25-35 µm, 8-spored, cylindrical, attenuate at the base, short pedunculate, bitunicate, thick-walled, physoclastic, persistent, with a canal in the tip, developing in the angle between covering and basal wall of the ascomata. Ascospores: 37-70 x 16-26 µm, ellipsoidal, 1-septate, brown, thick-walled, septum with a central pore. Spermagonia: associated with ascomata, gregarious or confluent, scutellate, immersed, then erumpent, ostiolate, epapillate, carbonaceous, black, irregularly chambered. Spermatiophores: obclavate, simple. Spermatia: subglobose to ellipsoidal, 1-septate, hyaline (Description: Based on Kohlmeyer & Kohlmeyer (1979)).


Key references:

Borse BD, Bhat DJ, Borse KN, Tuwas AR, Pawar NS (2012) Marine Fungi of India. Broadway Book Centre, India.

 Hyde KD, Jones EBG, Ariyawansha H, Liu JK, Binder M, Jayawardene N, Boehm E, Boonmee S et al. (2013) Families of Dothideomycetes. Fungal Diversity 63: 1-313.

Jones EBG, Suetrong S, Sakayaroj J, Bahkali AH, Abdel-Wahab MA, Boekhout T, Pang KL (2015) Classification of marine Ascomycota, Basidiomycota, Blastocladiomycota and Chytridiomycota. Fungal Diversity 73: 1-72.

Kohlmeyer J (1963) Zwei neu Ascomyceten-Gattungen auf Posidonia-Rhizomen. Nova Hedwigia. 6:5-13.

Zhang Y, Fournier J, Phookamsak R, Bahkali AH, Hyde KD (2013) Halotthiaceae fam. nov. (Pleosporales) accommodates the new genus Phaeoseptum and several other aquatic genera. Mycologia. 105(3):603-609


Type & Location:
Other Specimens:
On marine phanerograms (Posidonia oceanica).
Algeria, France, Greece, Italy, Yugoslavia, Liberia, Spain.
Pertinent Literature:
NOTES: Records of H. posidoniae on mangrove wood and the tropics is considered a misidentification (Prasannarai et al. 1999) as the fungus is host specific to rhizomes of Posidonia oceanica (Borse et al. 2012, Kohlmeyer & Kohlmeyer 1963, 1979, Jones et al. 2015). Genus accepted in the Dothideomycetes by Hyde et al. (2013) and Pleosporales by Zhang et al (2013) and Jones et al. (2015). Zhanh et al. (2013) introduced the family Halotthiaceae to accommodate the genera Halotthiaceae, Phaeoseptum, Pontoporeia and Mauritiana.


Mushroom Research Foundation 
Chiang Rai 


Sueggestions for improvement of the webiste, corrections or additions should be send to:

Gareth Jones: Email:

Mark Calabon: Email: