Zygocactus hybrids
by Derek Butcher, Australia (1999)

These hybrids, with their rather unique flower arrangement, have been in cultivation since early in the 1800s and have had surges of popularity. The 1990s was just the latest.

I have purposely used the term Zygocactus because this is the name predominant in the plant industry despite what the taxonomists have decreed are now Schlumbergera. The cultonomists haven't done much better either because rarely do you come across Schlumbergera "Buckleyi" or Schlumbergera "Reginae". The plant industry certainly follows the ICNCP rules of using Cultivar names although whether these are registered is another question!

If we read Bradleya 9 1991 page 90 we will see N. P. Taylor make comment that there may be a justification for the "S. truncata group" to be considered one species. Only recently has a specimen of  S. truncata been found in Domingos Martins, Espirito Santo to show that the spread is wider than thought in 1991.

I find it hard to imagine that S. kautskyi and S. orssichiana, or species in between that are now extinct because of human activity were not available to the collector in the 1800's and thus used to produce the many hybrids referred to in Britton & Rose. Were they totally Zygocactus truncatus hybrids or were there Schlumbergera "Buckleyi" and Schlumbergera "Reginae" mixed in with them!

Little has been written of the variability of colour in the flower in the wild although one would assume that red predominates. The shape of the flowers suggests humming bird pollination and red is attractive to birds. The berry is mostly red attracting other birds to spread the seed to other areas.

Little has been written as to how the yellowish tints that are now appearing in cultivars, arose and one wonders if Disocactus macranthus has been used or whether it has been purely selection.

Certainly, yellow was only mentioned in regard to Epiphyllum guedeneyi when The Cactaceae by Britton and Rose was published in 1920. At that time only Zygocactus truncatus was accepted and known. There was also Schlumbergera russelliana but it was linked to S. gaertneri rather than Z. truncatus. 

I find it fascinating that over fifty forms were known at the start of the 1900's and yet to this day there are some that find it necessary to patent their wares. To my mind it is just history repeating itself and what a marvellous and varied resource nature has given us.

Let us look at what is in The Cactaceae by Britton and Rose and you can decide for yourselves. Remember that the genus name Zygocactus did not come into being until 1890. 

"Cereus truncatus altensteinii (Salm-Dyck, Hort. Dyck. 65.  1834) occurs in literature, sometimes attributed to Otto, but we have seen no description. We follow Löfgren, who refers Zygocactus altensteinii to Z. truncatus. The type came from the Organ Mountains near Rio de Janeiro; in 1915, Dr. Rose visited these mountains, where he found the true Z. truncatus.

There are many garden varieties, most of which are very beautiful. Among these are Epiphyllum gibsonii, introduced in 1886, with dark orange-red flowers, and Epiphyllum guedeneyi of unknown origin, with large flowers, the outer segments white, tinged with sulphur, and the inner ones creamy white; the variety is referred by some to Phyllocactus guedeneyi. Nicholson (Dict. Gard. 1:517) describes some of the best as follows:

"Bicolor, white, edged with rose; coccineum, rich deep scarlet; elegans, bright orange-red, centre rich purple; magnificum, flowers large, white, tips bright rose-colored; roseum, bright rose; ruckerianum, deep reddish purple, with a rich violet centre; salmoneum, reddish salmon; spectabile, white, with delicate purple margin; violaceum superbum, pure white, rich deep purple edge." 

Rumpler (Forster, Handb. Cact. ed. 2.870, 871. 1885) described nine varieties, among which are cruentum and tricolor; E. truncatum cruentum was also briefly described by Morren (Belg, Hort. 16: 260. 1866). Among other varieties are albiflorum, aurantiacum,. grandidens, minus, purpuraceum, and vanhoutteanum.

Epiphyllum ruckeri Paxton (Mag. Bot. 12: 46. 1846) was described from cultivated plants of unknown origin as an improved variety of Epiphyllum  truncatum.  It may have been a hybrid.

Epiphyllum truncatum multiflorum was given as a synonym of Epiphyllum altensteinii by Pfeiffer (Enum. Cact. 128.1837).

Epiphyllum elegans Cels and E. violaceum Gels (Forster, Handb. Cact. 446. 1846) were supposed to be only varieties of Epiphyllum truncatum.

Schelle (Handb. Kakteenk. 223. 1907) lists more than 50 forms of Epiphyllum trun­catum; the following not hitherto mentioned by us under Epiphyllum have the regular Latin form:

amabile roseum,  carmineum,  gracile,  grandiflorum rubrum,  harrisonii,  lateritium album,  makoyanum,  maximum,  morellianum,  pallidum roseum,  purpureum,  rubrum violaceum,  salmoneum aurantiacum, salmoneum brasiliense,  salmoneum flavum,  salmoneum marginatum,  salmoneum rubrum,  snowi,  spectabile carmineum,  spectabile superbum,  splendens,  translucens,  violaceum album,  violaceum grandiflorum,  superbum

If you have any further information about these popular cultivars please let us know.