Posted this in the Commonthroat thread, but this is pretty significant lore so here it is in the worlduilding thread.

qfBqg /huff, early falling weakening whine, huff, short low weak growl/ refers to the fruits of two distinct species of tree. The two species are almost impossible to distinguish visually. One species uses its juicy bright red fruit to attract animals in order to spread its seeds. It's a favorite of tree dwellers, and was likely so for pre-sapient yinrih as well.

The other species evolved to mimic the fruit of the first species, but uses its fruit in a much more sinister way. Instead of using its fruit to attract seed dispersers, this fruit contains an extremely fast acting deadly neurotoxin. Smaller animals die before they can even finish the fruit, and larger animals are dead within a few minutes. Their dead bodies drop to the forest floor at the base of the tree, and the tree feeds off of their decomposing corpses.

The dangerous tree is counting on animals to mistake its fruit for that of the innocuous species in order to lure them into a deadly trap. So it's risky to eat red fruit because it may be tasty or it may be deadly. From there the concept of risk evolved into misfortune, and that's how red came to be associated with bad luck.

These trees also helped yinrih to move from scent marking to written language. Whenever a yinrih would find a good red fruit tree, they would draw a specific ink pattern on the leaves to tell other yinrih that the tree was safe to eat.