This worldwide collection features plants of documented wild origin from nearly every continent, with an emphasis on plants from mediterranean climates (California, Mediterranean Basin, Australia, South Africa, and Chile).
The arrangement of the outdoor collections is primarily geographic by continent of origin or by region including, , , , , , , , and .
The Garden holds one of the largest and most diverse collections in the United States:
19,300 accessions (each accession represents one or more plants in the Garden).
The five best-represented families are:
Cactus family (2,029 accessions; 1,198 taxa),
Sunflower family (1,002 accessions; 771 taxa),
family (1,030 accessions; 711 taxa),
Lily family (1,097 accessions; 675 taxa), and
Heath family (979 accessions; 614 taxa).
The remainder are distributed among other families in the collection, including approximately 690 accessions of ferns and fern allies.
Each genus is assigned to one plant family. These assignments are in a state of change due to research findings in plant relationships through the use of DNA techniques. The Garden uses the standard of, where applicable. A new edition of this manual is in progress, due out in 2010. The Garden will apply the names accepted in The Jepson Manual to the collection as resources allow. Names not addressed in The Jepson Manual will follow the standard set by the Angiosperm Phylogeny Group.
Detailed records are kept for each accession, including their place of origin, which enhances their scientific and educational value considerably. Each accession is accompanied by a public display label including accession number, family name, scientific name, and place of origin, and where appropriate, common name.
Voucher specimens for many of the collections are filed in the separately administered UC and Jepson Herbaria on campus. Vouchering of woody species and other long-lived perennials is on-going. Voucher/herbarium specimens are pressed, dried plant specimens that ideally include all morphological characters necessary for identification. They can last hundreds of years under careful storage conditions.
California native plants (over 2,900 accesssions) occupy approximately one-third of the area and are grouped by plant communities. These include nearly one-quarter of the state's native species (according to The Jepson Manual: Higher Plants of California, 1993) and 201 taxa on the California Native Plant Society's list of rare and endangered species.
Other outstanding collections in the native plant area include
Manzanitas (Arctostaphylos spp. with 202 accessions, 108 taxa),
California-Lilacs (Ceanothus spp. with 110 accessions, 78 taxa),
and an almost complete collection of California bulbous monocots in the Lily and Amaryllis families (Fritillaria, Calochortus, Lilium, Erythronium, Allium, Brodiaea with 219 accessions, 96 taxa).
California has a Mediterranean climate, with cool wet winters and warm dry summers. Species from other parts of the world with Mediterranean climates are featured in the Mediterranean, Australasian, Southern African, and South American geographic areas. These specimens illustrate important evolutionary, ecological, and biogeographic themes related to the distribution and evolution of Mediterranean floras and are of particular horticultural interest in the California landscape.
The Asian Area includes an outstanding Rhododendron collection (519 accessions, 330 taxa) including many mature tree rhododendrons that are too tender for most North American climates.
The New World Desert and indoor succulent collections (in the Arid House) include many specimens collected from South America during a series of six expeditions to the Andes sponsored by the garden between 1935 and mid-1960s. Many of these are type collections.
Special collections of orchids, ferns, carnivorous, and tropical plants are housed in greenhouses. The Cycad and Palm Garden features many interesting species in the vicinity of the Garden Conference Center.
Ethnobotanical collections include
The herbs in our Garden of Chinese Medicinal Plants are part of the everyday pharmacopeia in modern China and are widely used by Asians in the San Francisco Bay Area as well as a growing segment of the local non-Asian community. Development of this garden included participation of the American College of Traditional Chinese Medicine in San Francisco and the Guangzhou College of Traditional Chinese Medicine in Guangzhou, China.
We expanded our Mexico/Central American plant collection and anticipate increasing interest in this exhibit among members of our large Hispanic community, especially since ethnobotany and conservation will be emphasized as interpretive themes.
All our collections are on public display, with the exception of plants in propagation, research collections, and some indoor collections of ferns and epiphytes.
Each year we supply large quantities of plant material to other botanical gardens and research institutions. In addition to answering specific requests (research materials are shipped to over 50 individuals and institutions each year), we also publish a biennial seed list. The list includes wild-collected seed of California native plants and is shared with over 600 institutions world-wide. See “”
One of our principal collection policies is to limit acquisitions to wild-collected specimens of documented origin. We make exceptions in the case of plants for class material, plants of great taxonomic or morphological interest that are not otherwise obtainable, and plants for special collections (e.g. the Garden of Old Roses).
All 19,000-plus living accessions are in a computer data base (over 37,000 accessions including the “dead plant” records). Information recorded for each accession includes family, genus, species, accession number, collector and date of collection, original locality, habitat data, and location in the Garden.
All specimens are accessioned in the office as they arrive in the Garden. There are an average of 1500 new accessions each year. All specimens have permanent labels indicating (at the minimum) accession number, scientific name, family, and geographic origin. A red dot on the plant label marks rare or endangered species.
Curatorial volunteers collect information on flowering and fruiting dates for plants in the Garden, as well as assist with requests for research materials.