Asclepias, the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species. Pollination in this genus is accomplished in an unusual manner. Pollen is grouped into complex structures called pollinia (or “pollen sacs”), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower-visiting insects such as bees, wasps and butterflies, slip into one of the five slits in each flower formed by adjacent anthers. The bases of the pollinia then mechanically attach to the insect, pulling a pair of pollen sacs free when the pollinator flies off, assuming the insect is large enough to produce the necessary pulling force (if not, the insect may become trapped and die). Pollination is effected by the reverse procedure in which one of the pollinia becomes trapped within the anther slit.

Asclepias curassavica commonly known as Blood Flower or Scarlet Milkweed is an erect, evergreen perennial sub-shrub with opposite leaves and milky sap. The flowers are orange and red and are borne in terminal and axillary clusters that are 5-10cm across. It blooms continuously from spring until autumn. Asclepias curassavica is easy to grow, thriving in dry, moist, and even wet soils. Use scarlet milkweed in perennial borders and meadow gardens. Its dependable bright orange and red flowers stand out against the dark green foliage. Blood flower is a thin, unobtrusive little plant that can be squeezed in among other perennials and shrubs and still counted on to show off its pretty flowers. The plant attracts butterflies, bees, and birds.