Leaves and Stems. All sorts of leaves and stems are
used as food by various cultures, including such unusual offerings as young fern fronds
(fiddleheads) and "weeds" such as dandelions and lamb’s quarters.In general, leaves and stems provide relatively little energy
value, or calories, compared with other plant parts. However they do contain many
vitamins, minerals, and trace materials that are essential to a healthful diet.
Leaves we use as food include chard, spinach, collards,
kale, lettuce, and cabbage; also many herbs such as parsley, thyme, rosemary, and sage.
We eat the stems (shoots) of asparagus, and the leaf
petioles of rhubarb and celery.
Fruits. Similar to leaves and stems, many
fruits are relatively low in energy value, but are important sources of vitamins and
mineras. They are usually more perishable than roots or stems, and are therefore more
difficult to store and ship. Because of this, the juice is often extracted from fruits and
bottled for shipment.
A fruit, you’ll recall, is a matured ovary.
We’ve already mentioned some types of fruits, such as snap beans, in the previous
categories.
More than any of the other categories of food we’ve
discussed, fruits vary widely in their taste, size, shape, and nutritional value. Many
fruits contain large amounts of water and few calories; others, like the date, avocado,
banana, and fig are quite concentrated sources of energy.
Fruits can be categorized by the type of plants they come
from. For example, peppers, tomatoes, and squash—which we often refer to as
vegetables—are all technically fruits harvested from herbaceous annual plants.
If you think of fruits, however, some of the first
you’re likely to think of include perennial fruits of temperate climates. These
include peach, cherry, apricot, and plum (stone fruits, whose fruit is a drupe); pear and
apple (pome fruits); grape, blueberry, and persimmon (true berries); and raspberry and
strawberry (aggregate or accessory fruits).
Tropical fruits include banana, the various citrus fruits,
pineapple, avocado, guava, papaya, mango, breadfruit, date, kumquat, loquat, medlar, and
tamarind.
There are many other types of fruits, too numerous to
mention here. We'll talk a little more about fruits over the next two weeks as we explore
plant reproduction.
Let’s wrap up our discussion of food by imagining
your favorite fruit, picked at the peak of flavor, and waiting for you to savor its taste
and aroma.....
