Science

CVE: Part 2

	11. Date palm (Phoenix dactylifera). The date palm is extensively cultivated for its edible fruit. However, this particular example is a male and bears no fruit. These medium-sized trees often clump together with several trunks from a single root system or growing singly. We eat the seed or dates.
	12. Vines growing up trees. These vines are a good example of the strategy they use to get themselves up high enough to get sunlight.
	13. Black walnut (Juglans nigra). The black walnut or American walnut is a native of eastern North America. They are large deciduous trees with grey-black, deeply furrowed bark. The wood is of very high quality and used for furniture making. The leaves are pinnate with 15–23 leaflets. The largest leaflets are in the center of the leaf. The nuts are contained in a green husk that turns brown before it falls. The husk will stain your clothes or hands so be careful.
	14. Elm (Ulmus sp.). Elms are deciduous trees found throughout the Northern Hemisphere. They have simple, single- or double-serrate leaves. The flowers are pollinated by the wind. The wood of the elm has an interlocking grain and resists splitting. It is used for wheels and chair seats. Because the wood resists decay when wet, it was used for water pipes in mediaeval Europe.
	15. Washington thorn (Crataegus phaenopyrum). This deciduous broadleaf tree is in the hawthorn family. It has white flowers with yellowish pink anthers. The light brown bark is thin and smooth on young branches, but later becomes scaly. The leaves start out as bronze and quickly turn green and finally burgundy in the fall.
	16. Black spruce (Picea mariana). The black spruce is a common conifer tree in North America. It is a slow-growing, small tree. Its grayish brown bark is thin and scaly. The dark bluish green needles are ½ inches long and have four sides. The cones are the smallest of any spruce (0.5 to 1.2 inches) and are dark purple. They stay on the tree for several years.
	17. Adobe wall. The wall between the school and the Adobe Center is probably 150 years old. Adobe is clay that is allowed to dry in the sun. It was used by many people around the world as a convenient and useful building material.
	18. Mulberry (Morus sp.). Although this tree is a fruitless mulberry, other types produce a delicious dark berry. Mulberries grow fast when they are young and slow down later. They are usually less than 50 feet tall. The leaves are simple and often more lobed on juvenile than the mature branches. our in several species. Mulberry leaves, particularly those of the white mulberry, are eaten by the silkworm, whose cocoons are collected to make silk.
	19. Tree roots. Visible on the ground below are roots running in every direction. Tree roots cover a lot of area. The roots of Southern magnolias spread out nearly four times the diameter of the leaf crown. On average, tree roots spread about three times further than the dripline (a line enclosing all of the branches). In other words, a tree with a 10-foot spread of branches would have a root area 30 feet in diameter. Every tree species has its own type of root system. For instance, some oaks frequently develop tap roots; maples often do not. The arrangement of roots for any specific tree, however, will be determined by a variety of factors, such as the type and compaction of the soil and availability of water.
	20. Redwood (Sequoia sempervirens). The redwood is the world’s tallest tree. The tallest known specimen is 368 feet, but typically, they reach 200 feet or so. The trunk is reddish brown and much tapers from a very thick bottom to a thinner top. Sprouts grow from stumps, and in redwood forests, you can usually find circles of redwoods that that have grown up from the remains of the original tree. This is a very important tree for lumber.
	21. Cedar (Cedrus sp.). Cedars are closely related to the firs and have very similar cones. The trees grow to about 150 feet tall and have spicy-resinous scented wood. A layer of wax protects the evergreen leaves from water loss and causes their color to vary from bright grass-green to dark green to pale blue-green. The cones are barrel-shaped and 2-5 inches long and take a year to mature.