Christmas, Thanksgiving, & Easter cactus: How to tell them apart

I suspect there are quite a few more people on the planet who know that there are two separate plants known as Christmas cactus and Thanksgiving cactus then there are people who are able to correctly distinguish one from the other. Plant identification, after all, is harder than simply remembering plant names. However, I suspect even fewer people know that there is a third plant named the Easter cactus. All three of these plants are among a group of epiphytic succulents in the Cactaceae family native to Southern Brazil, which have become popular in many parts of the world as houseplants.
 
Let’s start with the Christmas cactus, Schlumbergera russelliana, a plant that grows natively in trees and on rocks in the Brazilian rainforest. Like the other two plants, it has leafless green stems that are segmented and adorned at the tips by colorful flowers. Each segment of the stem has teardrop, scalloped margins, with a few notches along each edge. The notches on the margins are cuneate, or rounded. Flowers are typically pink, though white, red, and bi-color varieties exist. The flowers are tubular shaped, hanging downward from the arching branches, and have a ‘flower within a flower’ appearance. The plant doesn’t know which holiday it is supposed to bloom nearest, of course, but flowering typically occurs in late fall or winter as initiated by short day length. Flowering will often be more consistent if plants are taken outdoors during summer and fall so that the plants experience the trigger of shortening days heading into fall.

Above left: Christmas cactus has leafless green stems with round, scalloped margins. Photo: Lestat (J. Mehlich), CC BY-SA 2.5. Above Right: Blooms. Photo: N. Barbieri, CC BY-SA 2.5.

Thanksgiving cactus, Schlumbergera truncata, shares many of those same attributes. However, the key identification feature is that the margins have somewhat sharp pointed teeth rather than the rounded ones found on Christmas cactus. Many botanists see the teeth at the very tip of each stem segment as resembling the claws of a crab, and therefore this plant is also sometimes referred to as claw cactus. If you too see crab claws, then you may find this a helpful way to identify this species. There are a wide range of bloom colors, including red, pink, orange, yellow, and white. Flowering is also triggered by short day length, and generally occurs a bit earlier in fall than the Christmas cactus, though it’s important to note that for both plants the timing of bloom will largely be dictated by the individual plant’s growing environment.  

The margins of Thanksgiving cactus have somewhat sharp pointed teeth rather than the rounded ones found on Christmas cactus. Left photo: M. Wei, CC BY-ND 4.0. Right photo: D. Sipler, CC BY 2.0.

Easter cactus, Rhipsalidopsis gaertneri, is the least common of the three in the houseplant trade, and also the earliest bloomer chronologically in a typical year, with blooms usually occurring between March and May. The stem segments are rounded and have noticeable yellow or brown bristles (hairs) at the tips. Flowers are star-shaped with many petals, and may be red, pink or white.

Photo, above right:  The least common. Photo: A. Laine, CC BY-NC 4.0

If growing any of these plants, they will do best in moist potting soil, preferably a cactus/succulent potting mix, with bright, indirect light and high humidity. When taking them outdoors in the summer, a shady location is best to avoid leaf scald. Easter cactus tends to be the most finicky of the three and will drop stem segments easily if overwatered or underwatered. This perhaps explains why they are not as frequently available for sale.
 
Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705.