An outstanding BLE (Broadleaf Evergreen) at JLBG this month is the amazing Prunus laurocerasus ‘Batumi Rubies’. This full-size form of the more commonly sold dwarf selections makes an amazing specimen. The fruit of this Black Sea native is typically black, but plantsman Todd Lasseigne made this amazing red-fruited collection in 2001, in the country of Georgia. Most people only know the species based on the numerous dwarf cultivars that are widely used for hedging, but we’ll take this full-size specimen any day. Our 18 year old plant is now 15′ tall x 15′ wide. Since we’ve grown it, we’ve also yet to see a seedling.
It’s widely written about the chemical toxicity of the fruit, but at the same time, the fruit is widely eaten by Black Sea inhabitants. Digging deeper, the species does indeed have very toxic fruit, that has been used for centuries for political assassinations as well as general murders. The fruit of English laurel, as it’s often called, contains cyanogenic glycoside, which when the cell walls are broken down (i.e. eaten), release the highly toxic Hydrogen cyanide. Cyanogenic glycosides are actually quite common in the plant world, being found commonly in members of the Euphorbia, Rose, Aster, Legume, Grass, and Passionflower families. So far, these chemicals have been documented from 1650 plants including 130 different plant families (Yamane, etal 2010). It’s byproduct, Hydrogen cyanide, however, has a much more nefarious track record. Anyone who studies history knows that Hydrogen cyanide has a long history of use by the Nazis and other such groups to exterminate humans.
According to people who study such things, the levels of cyanogenic glycoside is quite high when the fruits are developing, but disappear completely when the fruit fully ripens, making the fruit quite edible, hence its regional use fresh, in jams, pies, etc. This is most likely an evolutionary development to prevent dispersal before the seed is ripe. Supposedly, cooking, drying, or processing the fruit, also removes the toxins. Frankly, we’re not willing to be guinea pigs, and recommend that you don’t try it either, despite there being several named cultivars selected for edibility. Birds, on the other hand, seem not to care.