Sometimes called Orange Cosmos, Cosmos sulphureus is a favorite for flower-pressing crafts. Compared to its popular, pink-flowered cousin, Sulphur Cosmos grows into shorter, bushier plants and produces somewhat smaller yellow to orange semi-double flowers. Dwarf Lemon is even more compact than the species, growing to a height of just 18 to 30 inches, with sunny, lemon-yellow flowers. The flowers of these often remind me of open-style marigolds on larger plants.
See also the pink/white cosmos species, Cosmos bipinnatus.
The originals are wildflowers, of course, and are native to our own southwest and more commonly, Mexico. This tells you cosmos don't mind hot dry, conditions. In fact, some consider cosmos desert plants. But they're incredibly adaptable. And ever since some plant explorer gathered seeds from the rocky wilds of Mexico and transplanted them into "good garden soil," the world has known that they not only thrive, but enjoy our loamy, well-watered gardens. And if they're not fertilized too much, they rapidly develop into large branching plants with deep green fern-like leaves. If you have a dry season, cosmos plants don't care, and revert to their drought-tolerant roots. Best of all, no matter where they're growing, they cover themselves with more and more daisy-like blooms from midsummer on. Only a hard frost stops the cosmos parade. And the big bonus: a grand stand of this garden classic in late summer can provide months of long-stemmed cut flowers for a whole neighborhood.