English Youth-on-age Etymology From the way young plantlets sprout from the middle of older leaves. Noun youth-on-age (uncountable) A perennial plant native to North America and widely planted as an ornamental: Tolmiea menziesii 1972, Hazel Heckman, Island Year, page 132:Sometimes flowers of youth-on-age are white streaked with green instead of greenish streaked with purple. Synonyms (Tolmiea menziesii): hedge nettle, piggyback plant, thousand mothers References Tolmiea menziesii on Wikipedia.Wikipedia Tolmiea menziesii on Wikispecies.Wikispecies Tolmiea menziesii on Wikimedia Commons.Wikimedia Commons Wikiwand - on Seamless Wikipedia browsing. On steroids.