Having regard to the value of Redwood timber exported from America, and the rapidity with which it is developed, this species is well worth attention from any person or corporation planting on a large scale in a sufficiently humid climate, for it is to be noted that it is very impatient of drought. The Redwood Belt, extending from Sonoma County to Del Norte County, enjoys an average annual rainfall of 50 inches. Much less than that will serve the tree in the British Isles, owing to the sun being far less powerful over here than it is in California. Propagation is done from suckers, for, as is the case with some other trees—the English elm, for instance—the production of fertile seed is diminished or disappears with the acquirement of the suckering habit.
It has been claimed for the Redwood that it is the tallest growth in the world; but Australians dispute its title to that distinction on behalf of Eucalyptus amygdalina. The data for a verdict are as follows: In 1896 Professor Sargent measured a Redwood felled on the Eel River, and found it to be 340 feet high and 31 feet 3 inches in girth at 6½ feet from the ground. The rings of annual growth numbered 662. On the other hand, the height of two fallen eucalyptus have been recorded as 420 and 471 feet (the dome of St. Paul's Cathedral is 404 feet high); but Mr. Malden, Director of Sydney Botanic Garden, has declined to receive these measurements as trustworthy. It is very much to be desired that the truth should be ascertained before it be too late.
Not far in kin from the Redwood is the Western Hemlock (Tsuga albertiana), not to be confused (as it often has been by nurserymen and planters) with the Canadian Hemlock (T. canadensis), which is a tree of very inferior beauty and merit to the other. The Western Hemlock forms splendid forests in British Columbia, Washington and Oregon, attaining its greatest dimensions near the sea-coast, where Professor Sargent has recorded specimens 200 feet high and 20 or 30 feet in girth. Introduced to Great Britain by Jeffrey in 1851, it has proved itself contented with our climate, and is certainly one of the loveliest of exotic conifers. There are now many specimens in the United Kingdom measuring from 70 to 100 feet high. It is frost-hardy; but, to develop its true grace, must have shelter from wind exposure. Sargent reports very favourably of the timber, which is said to be disliked by rats and mice; but it does not seem to have been imported into Europe. Seed is plentifully produced, wherefore there is no excuse for the nefarious trick of reproduction by cuttings.
GINGKO BILOBA
At the Grove, Watford
The Gingko
The Gingko or Maidenhair-tree (Gingko biloba) is among the most interesting of trees, owing to its being, like the Araucaria, a survival of the vegetation prevailing when the aspect of our globe was very different from that which it bears now. Both Gingko and Araucaria were classed as conifers by the older botanists; but certain archaic features in each have been recognised as justifying their rearrangement in two separate natural orders.
The gingko has not been found anywhere in a wild state, and owes its preservation from an extremely remote past to the care which the Chinese have always shown to preserve part of the natural forest round their temples. It is in such situations that it is now found in China, Corea, and Japan; but Dr. Henry suggests that it may not improbably exist in the unexplored forests of central China.