Common name: Poinsettia, Christmas flower
As I am writing this in December 2020, nurseries, altar and malls are decorated with bright red Poinsettia flowers. They bloom during Christmas in the season’s color of green and bright red, though there are variants with pink, white, yellow, maroon colors; even variegated ones.
As you can guess, red poinsettias the ones most sold all over the world during December, over 70 million plants sold in US over a 6-week period. There are more than 150 cultivated variants of these plants grown in all parts of the world.
The colorful part of Poinsettia plants are bracts or modified leaves, and not actual flowers petals. Actual flowers are the small, yellow, inconspicuous ones at the center of the brightly colored bracts.
Poinsettia plants grow to a height of 10-12 inches. Left unpruned, they might grow tall and reedy. They should be pruned during non-blooming season to encourage the plant to grow bushy and branched. Store-bought plants need a lot of care to ensure that they grow well and bloom the next year as well.
These plants need well-drained soil, good sunlight and fertilization. During September and October, the plant should have 12-14 hours of complete darkness for the colorful bracts to develop. They should be kept in the sun for about 8 hours and in complete darkness, under a box or in a basement room for 12-14 hours. This process is essential for Poinsettia plants to bloom during winter. And this can only happen in winter.
Once they have developed the colorful blooms, they can be kept outside in sunlight. During warm summer months, Poinsettia plants have normal green leaves that looks quite plain. There are many calendars available online on caring for these plants post-blooming season.
Another close relative in the Euphorbiaceae family is Crown of thorns or Euphorbia milii, which is also characterized by bright, colorful bracts; but inconspicuous flowers. Similar to Crown of thorns, Poinsettia plants also have a white milky sap which could cause skin irritation on contact. The plant itself has some amount of toxicity, but not enough to harm humans or pet animals.
In early days, the plants were used as medicine for fever; and also to produce a red dye.
Propagation is through seeds or stem cuttings. Cuttings should be dipped in water to stop the sap, before planting.