Publication: Natl. Cact. Succ. J. (U. K.) 26(4): 100, 1971
Description
This is a very slow growing plant with an external layer of epidermal cell of Ortegocactus macdougallii that cover a second inner layer of tissues of Opuntia humifusa like a glove. The plant colour is the unmistakable grey-blue metallic tone of the Ortegocactus, but the plant shape is that of a minuscule Opuntia with small irregular cladodes up to 3-5 cm of length. This plant is quite unstable and have a tendency to revert to common Opuntia shoots.
Remarks: A graft-chimaeras can be given their own genus name (which is a combination of the two constituent generic names) preceded by a + sign. + Ortegopuntia derives from the combination of Ortegocactus and Opuntia.
Origin and Habitat
Garden origin (Nursery produced cultivar) Chimerical cultivar between Ortegocactus macdougalii and Opuntia compressa. Found and selected in the Cactus Art Nursery in the spring 2004 by Valentino Vallicelli.
Cultivation and Propagation
The plant seems of easily cultivation, the main difficulty is to eliminate the shoots that revert to the Opuntia type, it is advisable to water the plant moderately, in fact over-feeding and over-watering may enhance the growth of the more vigorous Opuntia tissues causing the reversion. This is a particularly slow growing plant (like Ortegocactus) and needs a sunny and warm exposure, and possibly winter temperature not less than 5-10° C. and good air ventilation.
Notes
Chimaeras of plants belonging to the Cactaceae family are very rare and quite unusual in cultivation. The first chimera + Hylocalycium (Hylocereus undatus + Gymnocalycium mihanovichii forma rubra “cv. Red Hibotan”, was described in cactus & succ .J. of America 1987 61- 4 2,
Recently some other chimerical cactus have been signalled in internet for example:
+ Myrtillocalycium (Myrtillocactus geometrizans + Gymonocalycium cv. Red Hibotan )
Gymnocalycium mihanovichii v. fleischerianum + Echinopsis tubiflora.
Gymnocalycium mihanovichii v. fleischerianum + Hylocereus guatamalensis
Ariocarpus retusus + Echinopsis eyriesii
Chimeras-graft appear more frequently among Ariocarpus sp. than among any other genus on stock of either Echinopsis sp. or Myrtillocactus geometrizans.
In some ornamental plants chimaeras may be the result of lengthwise implanting and sophisticated techniques, a possible methods include cutting the stem at the midpoint and combining the lobes of stock and scion. It is supposed that the miscellaneous tissues in the joint point can accrete and give life to an adventitious new plant “chimera”. But - as we know - nobody till now has succeeded to make cacti chimera on purpose. Circumstances which cause the chimera to appear include huge numbers of grafts.