The sago palm (Cycas revoluta) is a popular pick of residential gardeners and commercial landscapers in Solano County.
Drought tolerant, it survives temperature extremes from 15 to 110 degrees and grows in sun or shade. With dark semi-glossy green leaves and shaggy trunk, this plant grows slowly reaching a height of only 20 feet in 50 to 100 years. But few people realize that the sago palm is a relative of the most primitive of seed-bearing plants, the Cycad (cycadeoids), which is now extinct.
More than 150 million years ago during the Mesozoic era, cycads stood their ground against the dinosaurs. Providing plentiful food for the humongous herbivorous Stegosaurus, this plant flourished in abundance during the Jurassic period when ancient oceans distributed more of the sun’s heat from the equatorial regions to the polar areas resulting in a more uniform world climate without high latitude glaciers. (Source: www.fossilnews.com/1996/livingfossils.html)
Geologists the world over have discovered petrified cycads next to dinosaur bones. In 1994, juvenile remains of a Stegosaurus were found in Wyoming measuring 15 feet long and 7 feet high with a weight estimate when alive of 2.6 tons. A large fossil forest of cycads once existed in the Black Hills of South Dakota near Minnekahta and was designated “Fossil Cycad National Monument” before the find was depleted by vandals and collectors, and the area closed.
Here are some fascinating facts about cycads and sagos:
Cycads are called “living fossils” because they have remained unchanged through millions of years. Its habitat varies from tropical, to temperate and subtropical regions and includes dense forests and semidesert areas on several continents. These particular cycads are endangered, protected by global import and export regulations. True cycads comprise approximately 185 species in three families — Cycadaceae, Stangeriaceae and Zamiaceae. The sago palm (Cycas revoluta) is the only genus recognized in the Cycadaceae family.
The reason cycads and sagos are often confused with tree ferns or palm trees is that the whorl of leaves without side branches perched atop this plant’s central trunk resembles a fern or palm. Yet the cone-bearing Cycad is not related to the spore-bearing fern or the flower-producing palm. This gymnosperm’s closest cousins are conifers – firs, pines and spruce trees — along with the Chinese gingko. Research suggests a cycad’s relationship to these other living gymnosperms remains unclear. Gymnosperm means “naked seed” producing no fruit and no true flower.
Cycad pollination is via insects, small animals or wind. Seed sizes vary from as small as a pea to as large as a goose egg. Cycads form seed cones whereas the male sago palm forms a pollen cone. The female sago palm does not form a seed cone but instead megaporophylls, a group of leaf-like structures containing seeds. Pollination occurs through air movement.
The stiff narrow feather-like leaves of sago palms are often used in funeral wreaths or floral arrangements. They remain green long after cutting. Its Latin name revoluta means “curled back,” a specific reference to the leaves which grow outward in a circular pattern with new leaves emerging all at once periodically.
Italy’s Etruscan civilization placed fossilized cycad trunks atop their tombs as funeral monuments. In the United States, coal miners who found fossilized trunks took them home for doorstops.
This summer, if you’re looking for historically fascinating, drought-tolerant, long-lived plants for your garden, consider sago palms.
Five years ago I purchased one in a quart-sized pot for $10 at a local big box store and the plant is now over 4 feet tall and almost 4 feet wide. In no time at all, I was imagining the perilous life of the ancient cycads in the real “Jurassic Park.”
Launa Herrmann is a Master Gardener with the University of California Cooperative Extension office in Fairfield. If you have gardening questions, call the Master Gardener’s office at 784-1322.