Looks like a leaf fungus......

are those affected.. some of the oldest leaves????

are the most recent.. newest leaves affected ????

are we talking a couple leaves on a big plant???

how about a pic of the whole ...

its getting late in the season in the northern hemisphere ... even mexico ...

i am usually leery of worrying about things.. as we roll into late september ....

knowledge is power.. but it doesnt mean we need to react ...

ken

Thanks ians_gardener and ken_adrian for your follow-ups. I just wanted to make sure. It was on most of the leaves of a medium plant, 2.5 ft. What I did was I pinched off most of them with my fingers and the plant responded very well. Now it is growing vigorous and popping out multiple blooms. I recently bought an organic fungicide made of postassium bicarbonate, so I am going to use it for prevention of future fungal diseases. Thanks.