OAK 557 recent than that here adopted. The variable tree known in California as the scrub or ever- green oak is Q. agrifolia, which extends from the valley of the Sacramento to the Mexican California Evergreen Oak (Quercus agrifolia). border; it is, according to locality, a large shrub or a tree 30 or 40 ft. high ; its leaves, which are as variable as in the other species, are often sharply toothed, and the acorns elon gated, acute, and sometimes very narrow, like a cockspur. The European or British oak, or royal oak as it is often called, appears to vary quite as much as some of our species, different forms having been described as distinct species, and botanists are not agreed in regard to one of the commonest and most important European plants. Hooker and Bentham make but one species, Q. robur, and place what others call European Oak (Quercus robur). 1. Var. sessiliflora. 2. Var. pedunculate. Q. sessiliflora and Q. pedunculata as varieties of this, with the same names for the varieties as others give to the species. Q. robur is found over the whole of Europe except at the extreme north, and extends into Asia along the Cauca- sus ; it is the oak of poetry and history, and is one of the stateliest and longest-lived of the genus. It belongs to the same section with our white oaks, but has smaller leaves, which are not whitened beneath, and they are not deeply lobed ; the oblong acorn is over an inch long, in a short cup which is covered with short, obtuse, closely imbricated scales. In the variety sessiliflora the fruits are solitary or few in a cluster, nearly sessile in the axils of the leaves, which have petioles half an inch to an inch long, while in the variety pedunculata the fruits are clustered above the middle of a slender stalk, which varies from 1 to even 6 in. long ; the leaves vary from sessile to short- petioled. The first named is more abun- dant in North Wales and the hilly portions of northern England, while the other is the commonest over the greater part of England and the lowlands of Scotland. In durability the timber of the two varieties is regarded as equal ; but as that of the pedunculate oak shows more of the silver grain, it is more val- uable for cabinet work than the other. Each of these varieties has a dozen or more sub- varieties, marked by a distinct habit of growth or some striking form of foliage, which are made use of in ornamental planting. Some of the oaks now standing in England were old trees at the time of the conquest, and their re- mains so long as they retain any vitality are cherished with reverent care. This oak suc- ceeds remarkably in the United States, and to judge from the size of the older specimens now growing, it will after some centuries become even larger than in its native country. The Turkey oak (Q. cerris), a native of the south- ern parts of Europe, succeeds well in this country; its short-petioled leaves are deeply and unequally pinnated, and downy beneath ; the cup of the acorn is covered with bristly scales, on which account it is often called in England the mossy-cup oak. This has also produced several varieties, some of singular beauty; some are very spreading, and others are almost evergreen even in America, hold- ing their foliage nearly to Christmas. The timber of the Turkey oak is regarded as equal in value to that of the British oak. The com- mon evergreen species of Europe is the holm or holly oak (Q. ilex), abundant in the south- ern countries, especially in Italy and Spain, and extends to northern Africa and to Asia; it grows naturally on hilly ground near the sea, and in England has been found to grow upon the seashore where no other oak will live. It is a low or middle-sized tree, and is furnished with branches down to the ground, but if pruned may be made to grow much taller with a clean trunk; its leaves are thick, and either entire or toothed like those of the holly ; its wood is brown at the heart, fine-grained, hard, tough, elastic, and remarkably heavy, and greatly esteemed for ship building. It is a long-lived tree, and is the oak of Pliny and
