Each living organism on Earth has its own abundance and diversification at different period of time. While a fraction of species faces extinction, some still maintain their lives and breed until today, such as cycads. Cycads are one of the ancient groups of seed plants, which have a high longevity. They are called “living fossils” because they have survived since 65 million years ago, according to the University of California, Berkeley. Cycads were the dominant plants during the Mesozoic Era, the age of the dinosaurs. Mesozoic Era is divided into 3 periods: The Triassic, the Jurassic, and the Cretaceous. Based on the article Cycads not so ancient after all by Genelle Weule on ABC Science News, the Jurassic period is the time of cycads’ greatest abundance and diversity, in which they made up 20% of the world flora. For this reason, the Jurassic Era is often referred to as the “Age of Cycads.”
According to the University of California Museum Paleontology, Berkeley, cycads originally emerged in Pennsylvanian roughly 300 million years ago, even before the presence of dinosaurs. Yet now they occupy a variety of habitats; some grow in wet rainforests while others grow at hot and desert-like places. In a Horticulture Information article from the Wisconsin Master Gardener, Susan Mahr stated that, “more than 70% of the world’s cycad species occur in hotspots of diversity there and in Australia, South Africa, Mexico, China and Vietnam, but they also occur in the Southeastern US, Asia, India, Polynesia, Micronesia and elsewhere.” Although they have existed for about 300 million years, with time, cycads have evolved to possess similar structures to some current trees. There are many cycad fossils that have been found throughout history, yet only fossils of cycad’s leaves were preserved in the fossil records. For example, one of the preserved impression of fossil cycad leaves, Nilsonia vancouverensis, was collected from Lower Upper Cretaceous rocks off of Vancouver Island. Cycad fossils contain different parts of cycads, which have been used to reconstruct the cycads’ composition. Unfortunately, despite their usefulness, a fair amount of cycad fossils in Black Hills of South Dakota were terminated. This incident was discussed in the Earth magazine, in which Sara Pratt claim the reason to be the U.S Congress’s dissolution of the Fossil Cycad National Monument on September 1st, 1957 (Vol. 59, p. 114 – 116).
Based on some general information in Biological Science textbook, cycads come from Phylum Cycadophyta of the plant Kingdom Plantae. Cycads are considered to be gymnosperms – naked seeds – because they do not bear their seeds in an enclosed fruit; they bear their seeds naked on their leaves (Freeman, Quillin, Allison, et.al, p. 606). Each characteristic of cycad has its own features and brings different benefit to people. According to 4 Characteristics of Cycads by Judith Evans, cycad leaves maximally sprout up to more than 7 meters and their fat stems can grow an astonishing height of over 15 meters. For instances, Encephalartos laurentianus is one of the largest cycads on the planet that its leaves achieve to 7.62 feet long. Interestingly, cycad leaves can live up to four years and after the leaves die, their bases dry out and form a protective capsule on the stem. Cycad leaves store water, so they can highly abide drought. The leaves are often as large as the size of the trunk and they are usually used in ceremony, ritual, and decoration. Additionally, cycads are widely distributed across the globe and have long been exploited by people as a source of food and medicine. According to The Cycad Pages by Audhali and Stevenson, while a large amount of starch come from the trunk or root of some cycads, which is usually eaten by native people during famines, some tribes can change cycad seeds into a nutritious flour after an extended processing before any part can be safely eaten. Cycads produce cones and some of the cones are ornamental. Mature cones are subsequently open up to reveal their seeds. These seeds tend to be very colorful and usually attract a variety of birds and mammals in order to spread the seeds. Last but not least, different parts of cycad, namely stems, seeds, and roots can be very useful as medicine; they have been used as treatment for many illnesses and diseases. For instance, in Chinese traditional medicine, cycad seeds are used to treat hypertension, musculoskeletal disorders, gastrointestinal distress, and cough. With the impressive history and advantage of cycads, this ancient plant is doubtless an asset to our ecosystem.
Mesozoic Era is divided into 3 main periods: The Triassic, the Jurassic, and the Cretaceous. Among these periods, the Jurassic captured some historical intrigued components. This period was referred as the “Age of Cycads” because it was the time cycads were prevalent and most flourished. Cycads were a component of the flora with a long “living fossil” history that popular and beneficial during ancient time as well as modern time. Cycads are not only valued as food sources, but also can be used as effective medicine for many illnesses. Cycads are invaluable resources for our environment that need to be conserved.