Nurseryman Gary Hammer "risked life and limb, literally, to find new plants and bring them back" to Southern California, said Lili Singer, a horticulturist with the Theodore Payne Foundation in Sun Valley.
Early on Aug. 7, a car accidentally struck and killed Hammer while he was crossing a street in the dark in Tempe, Ariz., said his mother, Florence. He was 57.
He was staying overnight in the city on his way to Mexico City after the first leg of his plane trip was delayed, causing him to miss a connecting flight in Phoenix.
"Gary was absolutely legendary as a nurseryman, not just locally but internationally," Singer said. "He was an amazing guy. He brought back things that were valued and loved by people and have persisted in gardens."
In the 1970s, Hammer opened the wholesale-only Glendale Paradise Nursery, moving it to Lake View Terrace in the mid-1980s and eventually renaming it Worldwide Exotics. Later that decade, he also started a retail outlet, Desert to Jungle, in Montebello.
"Where on Earth," a 1997 guide to specialty nurseries, called him "a prime mover in the new horticulture of California."
By emphasizing plants that appeared tailor-made for the region — such as cacti and other desert offerings, shade-loving subtropicals and herbaceous perennials — Hammer helped transform the look and feel of the region's gardens, said Susan Heeger, a longtime local garden writer.
With his help, gardeners moved away from "thirsty Englishy-type perennials" that once crowded nurseries to "all manner of Australian, South African and Mexican natives" that he imported — and which thrived in Southern California, Heeger said in an e-mail.
Especially popular in the 1990s were such drought-tolerant Hammer selections as the bushy African sage and the aromatic Mexican stachys shrub.
After discovering a bright orange succulent often used for hedges in South Africa, Hammer brought two snippets home in the late 1980s and dubbed it Sticks on Fire. The plant proved popular and drew raves a decade later when it was installed in the Central Garden at the Getty Center.
"Everybody just adored and respected what he was doing," Singer said. "He had the coolest and most beautifully grown things that you couldn't get anywhere else."
Gary Edwin Hammer was born July 31, 1954, in Glendale, the eldest of two children. His grandfather owned an African violet nursery in Lake View Terrace.
After earning a bachelor's degree in horticulture from Cal Poly San Luis Obispo in 1976, Hammer briefly worked in banking before opening his Glendale nursery.
"I would scour nurseries for oddball plants," Hammer told Sunset magazine in 1998. "But I was never satisfied, because there weren't enough unusual plants out there."
So he became a plant explorer and was soon focused on mainland Mexico, which had a wealth of undocumented plants.
On plant-finding missions, he also traveled to such destinations as Thailand, Greece, New Zealand and South Africa, another country he favored for its plant diversity.
He came to love Mexico, his mother said, and moved from Glendale to Orizaba in the state of Veracruz. He closed Desert to Jungle and sold Worldwide Exotics but periodically returned to the United States to sell plants, often at flea markets.
Unconcerned with bragging rights for his many finds, Hammer would "joke that he almost didn't care about what a plant was named or if it was spelled right," said Kathy Musial, curator of the plant collection at the Huntington Library, Art Collections and Botanical Gardens in San Marino.
"Gary seemed to draw people to him," his mother said. "He touched a lot of lives with his plants and his personality. He had friends all over the world."
In addition to his parents, Dale and Florence Hammer of Cambria, Hammer is survived by a sister, Karen Hammer Nessen of Altadena.
His family is planning a service Sept. 17 in Chatsworth.