Approximately 33 mg, ~100 seeds
One of North America's best-loved annuals, Plains Coreopsis is also one of the easiest to grow. Plant spring or fall, and you'll soon see thin thread-like plants with shiny green stems and very small leaves. Once the seedlings are about 12" tall or so, perfectly round, brown-colored buds will appear, and soon you'll have the beautiful sprays of small butter yellow flowers with dark red centers. This species is great for cutting, each stem adding a whole flush of small flowers to any arrangement, but don't cut them all. Plains coreopsis is perhaps the very best native annual for reseeding. Which means even though the plants may die with frost, others will probably sprout in their places next spring. A great species, the official state wildflower of Florida.