The term PLANT WITH TRIANGULAR FRONDS can be solved by the four-letter word FERN. Ferns are a type of plant that have fronds, or leaves, that are divided into leaflets and arranged in a triangular pattern. They are found in many different climates and habitats, from tropical rainforests to temperate woodlands. Ferns reproduce by spores, rather than seeds, and are an important part of many ecosystems.