Ramularia grevilleana

(Tul. & C. Tul.) Jorst. emend. U. Braun var. grevilleana


LEAF SPOTS amphigenous, subcircular, angular to irregular, 1-8 mm diam, at first yellowish-ochraceous, sometimes reddish, later greyish white, with a narrow to broad, reddish, reddish brown to purplish violet margin.

 


CAESPITULI hypophyllous, punctiform to subeffuse, greyish white.


CONIDIOPHORES (cp) in small to moderately rich fascicles, loose to dense, arising from stromata, emerging through stomata, or erumpent, erect, subcylindric to geniculate-sinuous, straight, simple, aseptate to sparsely septate, hyaline, smooth, (5-)10-40(-60) x 1.5-5(-6) µm.

 


CONIDIA (c) catenate, sometimes in branched chains, narrowly ellipsoid-ovoid, subcylindric-fusiform, hyaline, almost smooth to verruculose, 0-2(-3)-septate, (8-)15-45(-55) x (1.5-)2.5-4.5(-5) µm; ends rounded or mostly slightly pointed; hila slightly thickened and darkened.

 


PLANT HOST AND DISTRIBUTION. Ramularia grevilleana var. grevilleana affects different plant species of the genera Duchesnea, Fragaria, Horkelia, Potentilla, and Waldsteinia (Rosaceae, Rosoideae, Potentilleae; Braun 1998).

According to Braun (1998), this fungus has an almost circuglobal distribution.


NOTES. The teleomorph of R. grevilleana var. grevilleana is Mycosphaerella fragariae (Tul.) Lindau. It has been recorded on Duchesnea indica (Andrz.) Focke and Potentilla supina L. from China (Braun 1998).


REFERENCE

Braun U. 1998. A monograph of Cercosporella, Ramularia and allied genera. Vol. 2. IHW-Verlag.