Perennial. This is a lovely South American milkweed native to Brazil and Argentina that was introduced by plant explorer K. Sahin ca. 1986. It differs from our Pacific Northwest milkweeds in that it grows to about 2' tall and has masses of pretty sky blue flowers that are about 1/2" across. Seed benefits from light and bottom heat for ideal germination. Plants tend to flop over so staking is useful. Perennial in mild winter areas. Can be grown in a pot and brought indoors. Flowers provide nectar for smaller pollinators. Not as attractive to Monarch caterpillars as our PNW native milkweeds.
* Growing Tip: Being an undomesticated plant, milkweed benefits from a period of cold stratification to help the seeds "wake up". To do this, one method is to plant in the fall, as wold happen in nature.
Or...you can place the seeds on a moist paper towel and put them in a plastic bag in the refrigerator for about 30 days. Check it periodically to see if mold is forming, in which case change the paper towel. This will greatly improve germination.
Milkweed, Narrow Leaf
Milkweed, Ice Ballet