Hypoderma De Not.

Hypoderma De Not., G. bot. ital. 2 (2): 13. 1847. Type. Hypoderma rubi (Pers.) DC., in Lamarck & de Candolle, Fl. franç., Edn 3 (Paris) 2: 304. 1805. Sexual morph. Ascomata elliptical to elongated elliptical, black, opening by a longitudinal split, usually subcuticular. Covering stroma formed by mostly dark brown, thick-walled, angular cells, in still closed ascomata with a row of thin-walled, paler cells in the inner half of the wall, along the preformed line of dehiscence. Basal Covering stroma formed prior to the development of the covering stroma or of differentiated asci or paraphyses, comprising several layers of brown, thick-walled, angular cells. Subhymenium consisting of small cells or textura porrecta. Paraphyses filiform, branched or not branched, sometimes with swollen tips, usually coiled at the tips. Asci ripening sequentially, cylindrical to clavate, thin-walled, J –, 8 - spored. Ascospores 0–1 septate, variable in shape, hyaline, usually covered by a gelatinous sheath. Asexual morph. Conidiomata, when present, small, subcuticular, circular in outline when viewed from above, lenticular when viewed in vertical section. Upper wall present or not. Lower wall lined with cylindric, solitary conidiogenous cells which proliferate either sympodially or percurrently. Conidia small, not septate, hyaline (Description based on Johnston 1990 a). Notes. Hypoderma is a large genus in Rhytismataceae and shares many morphological features with Lophodermium. De Notaris (1847) distinguished Hypoderma and Lophodermium by the shape of the ascospores, placing species with cylindrical to elliptical spores in the former, and those with filiform spores in the latter genus. Johnston (1990 a) redefined Hypoderma primarily based on features associated with the pattern of development in the sterile tissues of the ascomata rather than the shape of ascospores. Two species of Hypoderma are known growing on twigs of conifers, Hypoderma abietinum Ellis & Everh. and H. shimanense Y. Suto.