According to the United States Census Bureau, the city has a total area of 498.3 square miles (1,290.6 km²)—469.1 square miles (1,214.9 km²) of it is land and 29.2 square miles (75.7 km²) of it is water. The total area is 5.86% water.
The extreme north-south distance is 44 miles (71 km), the extreme east-west distance is 29 miles (47 km), and the length of the city boundary is 342 miles (550 km). The land area is the 9th largest in the Continental United States (excluding Juneau, Alaska and Honolulu, Hawaii).The highest point in Los Angeles is Sister Elsie Peak (5,080 feet) at the far reaches of the northeastern San Fernando Valley, part of Mt. Lukens. The Los Angeles River is a short, largely seasonal river flowing through the city, with headwaters in the San Fernando Valley. Its length is almost entirely lined in concrete.The Los Angeles area is remarkably rich in native plant species. With its beaches, dunes, wetlands, hills, mountains, and rivers, the area contains a number of important biological communities. The largest area is coastal sage scrub, which covers the hillsides in combustible chaparral. Native plants include: California poppy, matilija poppy, toyon, coast live oak, giant wild rye grass, and hundreds of others. Unfortunately, many native species are so rare as to be endangered, such as the Los Angeles sunflower.There are many exotic flowers and flowering trees that are blooming year-round, with subtle colors, including the jacaranda, hibiscus, phlox, bougainvillea, coral tree blossoms and bird of paradise. If there were no city here, flower-growing could still flourish as an industry, as it does in Lompoc. Wisteria has been known to grow to house-lot size, and in Descanso Gardens there are forests of camellia trees. Orchids require special attention in this Mediterranean climate.