They had recommended me a good place to buy dried chiles Oaxaqueño in the Central de Abastos. Have fun finding it - I only found it de puro milagro. Central de Abastos is huge, few visual cues that can be used as reference because everything looks alike, and all businesses have similar names (Oaxaca, Oaxaqueño, la Güera, ...).
Chile de onza is another traditional variety from Oaxaca. Its story is very similar to that of chile tabiche: I selected the best looking peppers, isolated their seeds and threw some seeds on a bit of dirt. Germination was quick (6 d) and I stored a good amount of seeds in the fridge. I transplanted four seedlings yesterday, hoping to end up with at least one or two plants.
I bought quite some dried peppers from that vendor... enough for the owner to ask me whether I was a professional chef . Off course... I bought 100 g of dried "chiltepín", which clearly contained a mixture of phenotypes. The vendor sources most of the peppers from the Sierra de Oaxaca.
I selected two types for growing. The first type is more rounded, with a blunt apex. Seeds were isolated from six chiltepines and a few were germinated. The first seedlings popped up after 10d. I transplanted two seedlings, hoping to end up with at least one plant. I nickname this type "Sierra de Oaxaca" (after their alledged origen) to differentiate it from two other chiltepines I'm currently growing.
I also selected a second type, but I haven't made the time yet to process and germinate its seeds.
Chile costeño can refer to various Mexican chiles. In Oaxaca, they have a costeño rojo (red) and amarillo (yellow). The chile from this post is costeño amarillo, although the dried peppers look pretty red... I used them in several preparation and the salsa colour always was yellow-orange - as should be the case with this pepper.
Again, I selected a few healthy-looking peppers and isolated the seeds. Their germination rate seems to be good enough I transplanted four seedlings, hoping to end up with one or two plants. I still haven't germinated the red version though...