Lithops ID

[N.D.]

Dear Lithops Experts, I had a stupidity of sowing L. optica and L. marmorata in the same pot, and now I cannot tell the difference. What does the plant with the flower look like to you:
L. optica C288 MG1679, or
L. marmorata 'framesii' SB1097 MG1665.8?

The plant to the left is pretty obviously L. otzeniana.

[iann]

I would go with L. marmorata from what I can see. Some distinguishing features you might want to look for:
- L. marmorata tends to be 6-merous, L. optica 5;
- L. optica tends to have fairly closed fissures (although obviously open when flowering) and lopsided leaves, L. marmorata more even leaves and more divergent;
- L. marmorata tends to have marbled windows, L. optica smooth clear windows although sometime partly occluded (Maculate form);
- L. optica tends to greenish, L. marmorata (framesii) to slightly pinkish;
- L. marmorata is medium to large, L. optica (and its flowers) small.

[N.D.]

Many thanks Ian! Now I have to save these difference. This is a lot more informative than what I could find in Treasures of the Veld.