Thanksgiving and Christmas cactus both bloom during the major holiday season. But how to distinguish between them? To avoid specific identification of these flowering succulents many garden centers market them under the generic label of Schlumbergera or lump them together with the label of “Holiday Cactus.”

These flowering succulents are both members of the genus Schlumbergera (SCHLUM-berg-er-a). The genus Schlumbergera was created in 1858 by Charles Lemaire who honored Frédéric Schlumberger (1823–93) as “a member of the distinguished French family Schlumberger, one of whose members was well-known in the mid-19th century for his collection of cacti at his château near Rouen (France).” (schlumbergera.net)

From afar, Thanksgiving and Christmas cacti have similar foliage, growth habit, and flowering characteristics yet they are distinctly different plants. They can be sorted out by comparing these same traits – foliage, growth habit, and flowering characteristics.

Foliage of both the Thanksgiving and Christmas cactus is unlike that of many other plants. The “leaves” of both are not botanically leaves, rather they are phylloclades (FILL-oh-clades); flattened, segmented, fleshy shoots or modified branches that function as a leaf. Their primary function is to carry out photosynthesis.

Phylloclades of the Thanksgiving cactus are heavily serrated with pointy, hornlike spikes protruding from the margins with an upright growth habit. An interesting side note from the National Gardening Association is that commercial growers like to grow them because of their upright growth habit, which allows plants to be more easily crowded together. 

Bloom time is November into January, around Thanksgiving or later. Blossoms are held at upright angles that resemble a bird taking flight. Flowers are tubular with compound interior structures that almost look like flowers within a flower. Blossoms come mostly in pastel colors from white, salmon, peach, orange to pink.  

The true Christmas cactus is less common than the Thanksgiving cactus. The Christmas cactus has flat, rounded, scalloped phylloclade stem segments that sprawl downward giving a growth habit that forms pendant chains. The pendant growth habit makes it a great candidate for hanging baskets.

Bloom time is later than the Thanksgiving cactus, usually December and into February. Blooms are round, bell-shaped that hang down from the tip of the phylloclade. Color of flowers are usually magentas, fuchsias, to hot pinks.   

Schlumbergeras are easily hybridized with the result that many of the plants labeled as “Holiday Cactus” have one or more predominant characteristics of both the Thanksgiving and Christmas cactus.

The Schlumbergera in the accompanying photo is the hybrid Thanksgiving cactus “Thor Cecilie”. Its registration (schlumbergera.net) discloses the hybridizer as Thoruplund of Denmark. “Thor Cecilie” is identified as a Thanksgiving cactus by its serrated, pointy phylloclade margins, brilliant white, upright flowers with broad, pointed petals, violet red pistil and white filaments with cream-colored pollen.

A Thanksgiving or any “Holiday” cactus make terrific Thanksgiving thank you gifts.

Wishing all Lubbock A-J readers a Happy Thanksgiving!

Note: Some information from garden.org

Ellen Peffley taught horticulture at the college level for 28 years, 25 of those at Texas Tech, during which time she developed two onion varieties. She is now the sole proprietor of From the Garden, a market garden farmette. You can email her at gardens@suddenlink.net

Source: lubbockonline.com