Genus Rickia Cavara

MB#4752

Malpighia 13: 182 (Cavara 1899). –

Type species: R. wasmannii Cavara

Distichomyces Thaxt., Proceedings of the American Academy of Arts and Sciences 41: 308 (Thaxter 1905) [MB#1673]

Brief description

Monoecious. Receptacle laminate, flattened, multiseriate, consisting of three vertical rows of cells known as anterior (ventral), posterior (dorsal) and median (axial) series. Sometimes the median series is missing. Anterior and posterior series bear secondary one-celled appendages and flask-shaped antheridia. In most species, the perithecium seems to be borne from the anterior series. Perithecium with four cells in each vertical row of outer wall cells.

Remarks

Rickia is one of the largest genera in Laboulbeniales consisting of 156 species, of which 16 in Europe, five in Denmark. The most recently described species is R. cifoneae (Rossi & Bernardi 2018) . For more details on the morphology of the genus Rickia see Santamaria et al. (2016).

Key to the Danish species (partially following Majewski 1994b and Santamaria et al. 2016)

1. Anterior series consisting of 2–5 cells.............................................................................................. 2

– Anterior series consisting of more than 16 cells. On Scaphisoma Leach, 1815 (Col. Staphylinidae Scaphidiinae) ................................................................................................. R. peyerimhoffii Maire

2. Anterior series consisting of two cells. Uppermost cell of posterior series (p 6) forming a conspicuous free pedicel that serves of base for the primary appendage. On Cylindroiulus Verhoeff, 1894 ( Diplopoda Julidae).................................................................................................. R. laboulbenioides De Kesel

– Anterior series consisting of 3–5 cells. Other characters not as above ............................................ 3

3. Antheridia numerous. Thallus more than 190 µm long. On Unciger Brandt, 1841 ( Diplopoda Julidae). ........................................................................................................... R. uncigeri Scheloske

– One to a few antheridia. Thallus less than 190 µm long. On Col. Staphylinidae ............................. 4

4. Perithecium with a narrow and fairly long neck. Antheridia on both, anterior and posterior series. On Proteinus Latreille, 1796 (Col. Staphylinidae).............................................. R. proteini T.Majewski

– Perithecial neck not as above. One or two antheridia on the anterior series. On Omalium Gravenhorst, 1802 (Col. Staphylinidae).................................................................................. R. huggertii Balazuc