CALIFORNIA SCRUB OAK (_Quercus dumosa_) has been a puzzle to botanists, and a hopeless enigma to laymen. Some would split the species into no fewer than three species and three varieties, basing distinctions on forms of leaves and acorns and other botanical differences; but Sudworth, after a prolonged study of this matter, recognized only one species and one variety, but admitted that “California scrub oak unquestionably varies more than all other oaks in the form and size of its leaves and acorns.” He thought it might possibly be equalled in that respect by _Quercus undulata_ of the Rocky Mountains. Some of the leaves of California scrub oak are three-fourths of an inch long and half an inch wide, while others may be four inches long. The edges of some leaves are as briery as the leaves of holly, others are comparatively smooth. The shapes and sizes of acorns vary as much as the leaves. Some are long and slender, others short and stocky. This peculiar oak is found only in California, but it shows a disposition to advance as far as possible into the sea, for it has gained a foothold on islands lying off the California coast, and it there finds its most acceptable habitat. It reaches its largest size in sheltered canyons on the islands, and attains a height of twenty or twenty-five feet, and a diameter of a foot or less. It is not large enough to win favor with lumbermen but in its scrubby form it is abundant in many localities. It is scattered over several thousand square miles, from nearly sea level up to 7,000 feet in the mountains of southern California. It is found scattered through the coast range and the Sierra Nevadas from Mendocino county to Lower California, 700 miles or more. It grows from sprouts and from acorns. The leaves adhere to the twigs thirteen months, and fall after the new crop has appeared. The wood is light brown, hard, and brittle. No use is made of it, except to a small extent for fuel. On the mountains it grows in thickets scarcely five feet high, but they cover the ground in dense jungles, and the roots go deep in the ground. The species is valuable chiefly for protection to steep slopes which would otherwise be without much growth of any kind. Being low on the ground, forest fires are particularly destructive to this oak; but its ability to send up sprouts repairs the damage to some extent.