Fern houseplants lend a verdant, boreal feel to indoor spaces. They set off flowering plants nicely, add texture, and have interesting foliage. Ferns have flourished on earth in many shapes and forms for millions of years. Leaflings unfurl in an intriguing and mysterious shape not unlike a fetus that opens and shifts shape as it reaches for light. Ferns are perfect examples of nature at work in a calculated way. Known as "the Fibonacci sequence", nature has placed leaves quite specifically and mathematically along a stem, ensuring that each leaf has maximum access to sunlight and rain. The Fibonacci sequence relates directly to the golden ratio, nature’s perfect proportion. As you move through the Fibonacci sequence, you'll eventually find nature's golden ratio, 1.618.