The answer is a Mushroom! (гриб) Mushrooms hunting (hodit' po griby) is quite important in Russia ... as food and social activity. It is even a bit of a sport among people, who compete for the best places to find tasty morsels. It is a real part of the culture, something almost every real Russian enjoys (well, except dearest Katja!) Don't worry dear, I didn't like picking fiddlehead ferns with my grandparents in Vermont too much either.
I happened upon this website devoted to the mushrooms in Russian culture and felt it was worth sharing.
From the website:
They (mushrooms) have played a tremendously important role during the wars that have plagued Russia's history. Many people have survived exclusively by supplementing their scarce diet with mushrooms. Mushrooms have even become part of Soviet ideology and of its notion of civil defense. I remember myself being told at school in Moscow that one had to be able to distinguish edible fungi from poisonous ones, so as to feed on the former and hence survive in the event of a war.With riddles, drawings, poems, and writings, the website author does a great job of plumbing the depths of Russian mushroom lore. They also provide information to inspire you to learn mushroom hunting yourself! (Although, if you poison yourself, don't blame me or the Mushroom Lore website - after all, even experienced hunters pick a bad one occasionally.)
In pre-Soviet times, the nutritious value of mushrooms was essential in yet another set of circumstances. The Orthodox Church exerted a profound influence on the eating habits of Russians in Tsarist Russia. Orthodox believers are required to fast between 178-200 days per year. As a result, Russian cuisine developed into a diet of opposites with frequent alternations between fasting and feasting.
Since meat and meat fat were prohibited during all fasting days, Russians took to mushrooms as a meat substitute. It is not surprising that mushrooms are referred to in a popular saying as Lenten Meat – postnoe myaso. In other words, this saying indicates that a Lenten meal was not a meal without the presence of mushrooms. Today, in modern Russia the problem of the supply and price of meat causes much grumbling among the Russian population. As a direct result ... in many areas of the country mushrooms are still a substitute for meat.