Russian origin. In Russia the Trifele varieties of tomatoes (of which there are several colors) are highly prized and command big prices. This short potato leaf plant yields prolific quantities of 6 oz. fruit that looks like a beautiful mahogany-colored Bartlett pear with greenish shoulders. Very tasty flesh with a meaty core that produces luscious fruit all summer long. Black Trifele seems to have a very low tolerance to Fusarium wilts. All the so-called Russian black tomatoes seem to have the sam issue. Optimum growing conditions for these cultivars is unquestionably needed. Readily available calcium and nuetral PH is helpful.