The Big Sleep repeatedly mentions pepper trees, and the annotations in my copy explain why:
This is the second mention of a tree that was once as emblematic of Los Angeles as the palm. Like the palm, the eucalyptus, and most other trees in LA, it is not a native. First planted by the Spanish padres to shade the missions, pepper trees were enthusiastically adopted by Anglo Angelenos, who lined the boulevards with the graceful shade trees. Many of these were later replaced by palms when it was found that pepper trees hosted black scale, a pest fatal to citrus crops.
Pepper trees were some of the first arrivals in the young city of Hollywood: in 1896 Harvey Henderson Wilcox, the founder of Hollywood, planted them along a freshly laid road — today’s Hollywood Boulevard — and began selling lots to the brand-new subdivision. The trees were removed in the 1920s because they blocked store signs on the commercial strip, despite a storm of protests to save them, including a campaign led by the actress Mary Pickford.
The trees became known as California pepper trees:
The California pepper tree (Schinus molle) is a fast-growing, hardy evergreen. With an established root system, the pepper tree requires very little rainfall and is considered to be the largest of all Schinus species, growing up to five stories tall. Its wide canopy and drooping branches give it an appearance that closely resembles a willow tree, making the two species visually similar.
However, crushed leaves from the pepper tree release a distinct aroma close to that of commercial black pepper and easily sets the pepper tree apart from the willow. The leaves are narrow and cone-shaped, appearing feather-like from a distance.
Bright red and pink berries decorate the branches, hanging together in grape-like bunches. As the tree ages, its outer grey bark peels to reveal its deep-red inner wood.
The California pepper tree received its colloquial name from its high abundance, cultivation, and long history in California. However, contrary to its nickname as the “California” pepper tree, Schinus molle originates from the arid regions of northern South America and the Peruvian Andes.
It has made its way across the globe and can be found in mild to warm climates. In certain regions, it is considered to be an invasive species. In South Africa and Australia, the pepper tree has encroached onto grasslands and dry areas. It often out-grows native plant species, gradually increasing in abundance and changing the local ecosystem.
In the United States, it is found in southern to south-western states and tends to crowd out native vegetation. Interestingly, it is not officially an invasive species in California given its long-term presence, common planting, and relatively low risk in comparison to other invasive plants.