168 THE ESSEX NATURALIST.
Several trees are to be seen in Woodford and Snaresbrook
gardens, where one of the Red-woods is about 40 feet high.
Sequoias have cones with shield-shaped bracts, each bearing
many ovules. S. gigantea has stiff, pointed, scale-like foliage,
while S. sempervirens has foliage like the Yew. In both species,
the red-brown felt-like bark is very thick. To give an idea of
the stupendous size the Mammoth Trees attain, figures seem to
convey but an imperfect impression. One of the trees felled
in the Yosemite Valley had a girth of 93 feet near the base, a
height of 363 feet, and the bark was a foot and a half thick; the
age, calculated by the number of annual rings, was over 3,000
years.
Taxodium distichum, the Swamp, Bald or Deciduous Cypress,
is remarkable amongst conifers in shedding its leaf-shoots every
year. The bright-green feathery foliage appears about the begin-
ning of May. The ripe cone is about the size of a pigeon's egg,
and consists of hard shield-shaped bracts, each bearing two seeds.
When growing in wet ground, curious hollow knee-like branches
grow up from the roots, which are thought to have an aerating
function. The Bald Cypress inhabits swampy land in the
Southern States of North America, where it is a large and valua-
able tree. Mention has already been made of its remains having
been found in the Bovey Tracey beds, associated with Sequoia.
It has long been cultivated in England, having been introduced
in the time of Charles I. It may be seen in several gardens in
this neighbourhood; one tree at Snaresbrook is especially
well grown and is about 50 feet high.
We now come to the Cypress group, many species of which
are not easy to distinguish without their cones.
Libocedrus decurrens (syn. Thuya gigantea Nutt.), the
Incense Cedar, is a noble tree in its home in the Sierra Nevada
("Snowy Mountains ) of California. Old trees have a straight
trunk from 40 to 140 feet high, crowned with an umbrella-shaped
top. The pointed compressed scale-like foliage is arranged
in four rows, in two opposite pairs, two median, two marginal;
but the pairs are so nearly on a level as almost to form a whorl
of four, which gives a jointed aspect to the stiff ascending branch-
lets. Cones are very rarely produced in England. A small
tree about 18 feet high grows in a Snaresbrook garden.
The genus Thuya, or Arbor-Vitae, differs from Libocedrus