Scolecostigmina yuccae

On living leaves of Yucca filamentosa, formerly known as Cercospora yuccae, causing circular to angular leaf spots, dark brown with violaceous tones, with a slightly paler and well-delimited growing margin.

Stromata minute, brown, rupturing the leaf tissue, only 20 to 50 µm in diameter.

Conidiophores cylindrical, straight to sinuous, simple to occasionally branched, 30 to 80 µm long and 4 to 10 µm wide.

Conidiogenous cells located at the tips of the conidiophores, occasionally arising directly from the base of the stroma, 15 to 30 µm long and identical in width to the conidiophores (4 to 10 µm).

Conidia subcylindrical, with a rounded apex and truncate base, pale brown under the microscope, 31 to 50 µm long (though according to literature reaching up to 120 µm), 5 to 6 µm wide, septate with one to four septa and slightly constricted at the septa.

Very similar to its congener Scolecostigmina concentrica, which occurs on the same substrate but with narrower conidia 3 to 5 µm wide.