Coriandrum Sativum . . . also known as Chinese parsley.
The leafy part is called Cilantro, the seed is known as Coriander.
Cilantro loses its flavor when dried or cooked, so it is best used fresh.
Since Cilantro plants grow and go to seed quickly, it is best to plant them continuously (every three weeks is suggested) throughout the growing season (spring and fall) to keep the crop going. Summer heat will speed up the growing process, quickly seeding the plants when soil temperatures reach 75 degrees.
The plants love growing in a moist, well-drained soil mulched with compost for nutrients and root protection to keep the soil cooler to prolong growing. The shade from closely growing plants also keeps the roots cooler.
The plants do not grow well indoors . . . they require mostly full sun, although it is possible to grow in morning sun and afternoon shade. In general, they are a cool season plant and best grown in the ground since they don't tolerate transplanting well.
To prolong leaf growing, trim off flower heads as soon as they start to flower. You can allow the flowers to mature and seed . . . they will resow and another crop will be ready in a few weeks. The seeds can also be collected when they turn brown to use as coriander or to dry out and save for replanting. Keep your seeds in an airtight container in a cool, dark place for use as a culinary spice in cooking or as seeds for next year's crop.
The cilantro leaves are ready to harvest about 8 weeks from seed and can be cut any time during the growth period. Cutting the outer leaves first is recommended so the smaller leaves can continue to grow. It is best to harvest before it begins to seed, which produces bitter tasting leaves.