"The seed is the matured ovule, containing the small plant (an embryo) with enough food to start its development," said
Linnaueus, considered one of the parents of botany. But that may be okay for birds, many of which have special ways to digest seeds; the question is whether it's any good for us. The answer is a resounding "yes," but let's take a look at just what makes seeds such good food for people.The botany stuff with the big confusing words (like endocarp and epicotyl) is all about distinguishing which part will grow into which part, and whether the part came from the mother, the father, or is new and came from the embryo. (It helps me to think of mammals: sperm from the father, placenta from the mother, and umbilical cord from the baby.)
The seed protects the young plant and gets it off to the right start, by providing the infant plants with nourishment. Angiosperms experience dormancy, when and if needed. The seeds don't all sprout and form new plants instantly, which has allowed humans to collect them, store them, cross them, study them and (if I may be so bold) develop agricultural societies.
The fleshy covering of a seed may be what we mere mortals think of as "the fruit," but in some seeds (sunflower seeds, cumin and coriander seeds, to name a few) the fruit is dried and actually is fed to humans as seeds. Many structures commonly referred to as "seeds" are actually dry fruits. The sunflower "shell" is the botanical equivalent of the yummy green stuff of an avocado, but dried into a hard outer "hull." Commercial sunflower seeds are sold both still enclosed within the hard wall of the fruit or "shelled," with the inner edible part exposed.
With many seeds like beans and sunflower, where what we eat is part of the embryo, the developing seed has already consumed the endosperm. In "stone fruits" (peach, plum, and other drupes), the endocarp is the fruit itself, and it surrounds the actual seed--the pit. Tree nuts are the one-seeded, hard-shelled fruit of some plants with an indehiscent seed (dry, not juicy), such as an acorn or hazelnut.
Most plant foods are seeds, when you think about it. We eat many different parts of plants for food, from roots to bark to leaves, but far and away the most important plant part for human nutrition, from the dawn of pre-history through the present day, are the seeds. From fruits and vegetables containing seeds, the coconut (a giant seed) to bananas (those tiny dark dots running lengthwise down the center of the banana are the seeds, and the banana is a giant berry), we rely on seeds for food. Even when we're not eating foods directly containg seeds, or made from seeds (like white flour--processed wheat seeds--or modified food starch, or high fructose corn syrup allegedly made from corn), we're eating meat that ate seeds (cattle, pork, poultry and other meat is fed food made from mostly seeds--wheat, corn, and other stuff).
Nuts are seeds, corn kernels are seeds, beans are seeds, grains of wheat, rye, barley, or oats are seeds, a coconut is a giant seed, tree nuts are all seeds, peanuts and peas and other legumes are all seeds.Sometimes seeds have a thin, non-edible endocarp (peanuts) and sometimes we eat the endocarp too (skin of peas, edible peapods). Sometimes the fruit itself is the endocarp and we discard the seed (avocado, melon)
I think, though, that my friend had in mind the seeds people eat that include the hull, or endocarp, the ones that look like what you might feed your feathered friends in the winter. Not just sesame seeds but flax seeds, pumpkin seeds, chia seeds, alfalfa seeds (and, indeed sprouts), sunflower seeds, hemp seeds, celery seeds, caraway seeds, pomegranate seeds, or spices made from ground-up seeds. Some people have trouble digesting the seedcoat or thin hull of seeds like legumes (peanuts and beans). Some people have trouble with the high fiber content of dry beans or the crunchy hulls of flax seeds, sesame seeds or caraway seeds. Read this blogger on incorporating flax seeds.
But the high protein, high fiber, high fat seeds have gotten a bad rap from dieters. The trick is that it's all "good fat" with seeds. The fiber means you feel full longer, the fat means you feel satisfied longer, and the protein means you'll stay alive!
If you don't like seeds, then by all means, don't force yourself to eat them! But if, like me, you adore and relish them, no need to feel guilty! Seeds protect and nourish the embryo or young plant, and they can protect and nourish you. If you wish to partake of the additional nutritional bonus of eating seeds and have trouble digesting or chewing them, try grinding them (in a food or nut grinder, a food processor or a blender) and then sneaking a little bit at a time into your favorite recipes. For instance, sprinkle a little ground almond meal or flax seed meal in next time you bake bread or muffins, use cornmeal or pulverized oatmeal or grated or shredded coconut when you bread fish or chicken, and sprinkle a few ground hazelnuts or chopped pecans into your morning cereal.
picture credits: seed thumbnail, Xandert at morguefiles.com. birds and birds feeding Lee Anne Stark. Avocado seed diagram