Cycad & Palm Garden
This collection echoes the environment of a prehistoric forest—where cycads and palms offer a critical link to the earliest of the ancient seed plants.
These plants flourished when dinosaurs roamed the Earth and reached their peak in the Mesozoic Era—from 66 to 252 million years ago. However, while palms and cycads may share certain physical resemblances, they’re not closely related. Victorian-era botanists mistakenly grouped these two plant types together and created palm and cycad gardens similar to the one here.
Regions
Some of these species share similar habitats in tropical, subtropical, and warm-temperate regions of the world. This collection focuses on those found in warm-temperate regions of the Americas, Africa, Asia, and Australia, showcasing the wide variety of cycad and palm species that can be successfully grown in the San Francisco Bay Area’s Mediterranean climate. Some of these plants are also found in the Garden’s geographic collections.
Collection Highlights
Cycads
Cycads are cone-bearing plants, more closely related to conifers than to flowering plants. They have thick leaves, a squat trunk (called a caudex), and special roots that host nitrogen-fixing bacteria. All species are dioecious, meaning that each plant is either male or female. Seeds formed in the female cone have brightly colored fleshy covering that may attract the attention of birds, rodents, and bats. These animals eat the outer covering and deposit the inedible seed within, thereby dispersing the plant.
Most cycads are slow-growing and limited in distribution, often due to poaching and habitat loss. This garden is one of four cycad collections accredited by the Plant Collections Network (PCN—a program of the USDA Agricultural Research Service and the American Public Gardens Association). It is also a member of the Global Conservation Consortium for cycads, a global network dedicated to the conservation of cycad diversity.
The collection is very broad, containing all the recognized genera of cycads worldwide, with particular strength of the genus Encephalartos from southern Africa. Many of these are critically endangered species, with some being extinct in the wild. The Garden is focused on this collection’s conservation importance and is working to establish a breeding program for these plants in collaboration with fellow PCN gardens and collaborators in South Africa.
Palms
Palms are flowering plants belonging to the family Arecaceae. While we refer to them as trees, they are in fact monocots, making them more closely related to grasses than to pines or oaks. A palm’s trunk has vessels called xylem and phloem that move water and nutrients through the plant. In a palm these are arranged in bundles throughout the interior of the trunk; woody trees, in contrast, have these vessels arranged in a circle on the outside of the trunk, separated by a layer of tissue called cambium. The growth of cambium accounts for the rings we see in a cut tree. Because palms do not have this, the tree does not grow in girth in the typical way, and if you cut a palm you wouldn’t see such rings.
There are more than 2,000 species of palms in the world, living in climates from very wet to very dry. They can differ in the number of trunks they produce, the attachment of their leaves, and many other morphological features. Palms are one of the most economically important crops of the world, with different species producing dates, coconuts, fibers, and oils. They’ve been used in horticulture for millennia, with the earliest depiction of Egyptian tomb gardens featuring two rows of date palms (Phoenix dactylifera).
Banner photo: A variety of palms in this collection.