COCCOMYCES De Not. Rhytismataceae. 4 Ukrainian species on Pinus, Quercus and Vaccinium and occasionally other broadleaved trees. Several species of Coccomyces known from central Europe, but not yet from Ukraine, may be worth looking for. These include: Coccomyces arctostaphyli (on Arctostaphylos leaves), Coccomyces atactus (on wood of Picea), Coccomyces cembrae (on wood of Pinus), Coccomyces ledi (on stems of Ledum), Coccomyces strobilicola (on cones of Picea) and Coccomyces tumidus (on leaves of Quercus, Fagus and other broadleaved trees).

1	asci 4- or 8-spored; ascospores about 5 mm wide; paraphyses up to about 4 mm wide at the tips, straight, often with apical crystalline deposits; on twigs of Vaccinium	Coccomyces leptideus
	not this combination of characters	2
2 (1)	ascomata often crystalline deposits in the exciple; on twigs of Pinus	Coccomyces strobi
	not this combination of characters	3
3 (2)	ascomata ripe in spring, conidial stage and thin black zone lines conspicuous, on pale areas of otherwise structurally intact brown dead fallen leaves of Fagus or Quercus	Coccomyces dentatus
	ascomata ripe in autumn, conidial stage and zone lines inconspicuous or absent, on totally pale and fragile dead, fallen and often buried leaves of Fagus, Populus and Quercus	Coccomyces coronatus

Coccomyces coronatus (Schumach.) De Not. Status. Native; 13 records since 28 August 1927; probably widespread and overlooked. Months. April, June, July, August, October. Regions. Kiev, Lviv, Zakarpatska. Habitat. On pale, fragile, dead fallen leaves of Fagus sylvatica, Fagus sp., Populus sp., Quercus robur, Quercus sp. Notes. To distinguish this species from other members of the genus on the Fagaceae, see the notes under C. dentatus. Worldwide. Coccomyces coronatus is widely distributed on dead fallen leaves of the Fagaceae in Europe, with additional records from North America and north Africa. References. Minter & Dudka (1996) [Ukrainian records]; Morochovskii, Zerova, Lavitskaya & Smitskaya (1969) [Ukrainian records]; Sherwood (1980) [description, illustration].

Coccomyces dentatus (J.C. Schmidt & Kunze) Sacc. Status. Native; 12 records since 16 August 1901; apparently not very abundant, most records being of the pale areas typical of colonies rather than of the fruitbodies themselves. Months. May, July, August. Regions. Crimea, Ivano-Frankivsk, Zakarpatska. Habitat. On dead fallen leaves of Fagus sylvatica, Populus sp., Quercus petraea, Quercus robur and Quercus sp.; probably always fruiting within 12 months of leaf death. Notes. This species may be easily distinguished from Coccomyces coronatus and Coccomyces tumidus (not yet recorded from Ukraine) [click here for picture] because the colonies are on paler parts of otherwise brown, structually intact, dead fallen leaves, usually with a rather sudden change in colour between the pale colony area and the darker remaining part of the leaf; zone lines and conidiomata are usually abundantly produced; leaves colonized by Coccomyces dentatus tend to remain rather separate from adjacent fallen leaves, and the ascomata mature in spring and early summer; by comparison, Coccomyces coronatus and Coccomyces tumidus tend to occur on whitish, fragile dead fallen leaves which are often stuck to other adjacent dead leaves, they do not produce abundant zone lines or conidiomata, and their ascomata mature in late summer to autumn; ascospore length may also be used to distinguish Coccomyces coronatus (60-80 mm) from Coccomyces tumidus (30-45 mm), with which it is often confused. Worldwide. Coccomyces dentatus is widely distributed and locally abundant in Europe and North America, on dead fallen leaves, mainly but not exclusively of the Fagaceae; additional records exist from north Africa and, possibly of this fungus, from South America. References. Minter & Dudka (1996) [Ukrainian records]; Morochovskii, Zerova, Lavitskaya & Smitskaya (1969) [Ukrainian records]; Sherwood (1980) [description, illustration].

Coccomyces leptideus (Fr.) B. Erikss. [click here for picture]. Status. Native; 1 record on 19 July 1994, probably local and previously overlooked. Months. July. Regions. Zakarpatska. Habitat. Vaccinium myrtillus; fruiting on pale areas of dead, rather brittle, attached twigs and pale areas of dead bark on living twigs; probably always fruiting within 12 months of twig death. Notes. The only Coccomyces species known on Vaccinium twigs; most easily found where Vaccinium myrtillus has grown more than 30 cm high, but can be found even on very short stems in mountainous habitats. Worldwide. Widely distributed and locally common on Vaccinium, particularly Vaccinium myrtillus, in northern, western and central Europe; also recorded from North America. References. Minter (1997a) [description]; Minter & Dudka (1996) [Ukrainian records].

Coccomyces strobi J. Reid & Cain [click here for picture]. Status. Introduced; 3 records since 6 May 1950; very occasionally encountered in botanical gardens, arboreta and other collections. Months. May, June. Regions. Crimea, Ternopil. Habitat. Dead attached rather brittle twigs of Pinus strobus. Notes. Two subspecies exist; Ukrainian records are probably of the typical subspecies strobi; rather similar to species of Therrya in the field, but easily distinguished microscopically by its aseptate ascospores. Worldwide. A native of North America, on recently killed twigs of 5-needle pines, particularly Pinus strobus; a few records as an introduction in Europe. References. Minter (1997b) [description]; Minter & Dudka (1996) [Ukrainian records]; Morochovskii, Zerova, Lavitskaya & Smitskaya (1969) [Ukrainian records].