Cactus : From the Greek word kaktos, meaning prickly plant.
Found mainly in southwestern USA and Central and
South America.
There are two main groups of cacti, the desert ones and the jungle (rainforest) cacti. Most members of both groups are succulent. They have juicy tissue, meaning that they store water in their leaves or main body.
Only the desert group has spines. It is commonly thought that the spines are to protect the plant from herbivorous feeders; in actuality, the spines (or, in some cases, bristles) are used to maximize the surface of the plant for moisture collection. In many desert areas the only source of moisture during the dry periods is wet mists. Desert cacti collect water by condensing the water from the mists on their spines.
The jungle cacti, mainly spineless and generally epiphytes (living in trees without being parasitic), can exist in an environment having as much as 400 centimeters annual rainfall.
The houseplant commonly known as "Christmas cactus" had its origins in the rainforest of Brazil in the mid-1800’s. Today it is one of the three most popular Christmas holiday plants in Australia, Europe and North America. It is also one of the most abused, i.e. poorly cared for, and resistant indoor plant sold today.
Millions are purchased and given as gifts every year. If they are not tossed out after their blooming period, they languish on a windowsill or coffee table until the next Christmas season rolls around. They may or may not produce a few feeble blooms at that time. Eventually they are discarded.
Christmas cacti, properly cared for, can and do thrive for many decades. It is not unusual for 40- or 50-year old plants to outlive their caretakers. They are often passed down to the next family generation. These long-living plants will develop what appears to be bark and reach a size of several feet with hundreds of blossoms during the annual flowering period.
The original Christmas cactus was developed by French botanist Charles Lemaire and named after French horticulture collector, Frédéric Schlumberger. Schlumbergera is the correct botanical name but they are frequently called Zygocactus, their former botanical name. In some countries they are also considered to be saxicolous, although this is difficult to equate with a plant originating in the canopy of a rainforest. Undoubtedly, they are capable of living among rocks.
There are some 300 hybrid varieties existing in various shades and combinations of white, pink, red, fuchsia and – more rarely – orange and yellow. The flowers, appearing at the tips of the last flat, fleshy and oval leaf on a stalk, are narrow and trumpet-shaped, either single or multiple. The multiple versions generally have one trumpet opening from the center of another, forming a pendulous cluster.
The Christmas cactus is a thermo-photoperiodic plant. The formation of the bud is dependent on a particular combination of day length and temperature. In the Northern Hemisphere these plants will began the blooming process when the length of the day is approximately equal to the length of the night and when the temperature is in the range of 50 to 60 degrees F.
The ancestors of today’s Christmas cactus were found in southeast Brazil, not far from the Equator. The first to be found, Schlumbergera truncata, was first mentioned in 1819 and flowers in October and November; this became what is now called the "Thanksgiving cactus". Another, the Schlumbergera russelliana, discovered in 1837, blooms between February and April; this became the "Easter cactus".
A hybrid of these two became the first "Christmas cactus". It will generally start forming buds in September, and began blossoming at end-December. Individual flowers last anywhere from 3 or four days to a week, but the blossoming period can last up to six or eight weeks depending on the variety.
There are two other main species from which most Christmas cacti have been developed. These are Schlumbergera opuntioides, named in 1905, and Schlumbergera orssichiana, discovered only in 1978. This last, discovered by Béatrix Orssich, a hybrid developer in Brazil, is the forerunner of the “Queen” sub-variety.
Orssich first crossed the S. orssichiana with the S. trucata. This lead to plants with much larger flowers than had been previously produced with a shorter “tube” on the trumpet shape, resulting in a denser joining of individual trumpets. A Christmas cactus with “Queen” or “Reine” in its name is a descendant of this hybrid.
The story of the development of the Schlumbergera X “Gold Charm” is worth recounting. Christmas cacti existed in white (developed from pink, which had been developed from red), cream, and orange, but not in yellow. A hybrid developer and producer in the United States, Cobia, decided to research a yellow flowering Schlumbergera . More than 50,000 seeds were selected and plants cultivated until, finally, one plant was produced that bore yellow flowers. Unfortunately, this sole plant had a scrawny appearance that would not be commercially acceptable.
It was therefore decided to cross it with a white-flowering Schlumbergera with a vigorous appearance. The resulting plant produced 200 seeds. The 200 seeds produced 150 plants with yellow flowers and, of these 150 plants, one was selected to become the Schlumbergera X “Gold Charm”. Fifteen years of research elapsed between the decision to find a yellow Schlumbergera and its introduction in the commercial market.
Caring for a Christmas cactus is not complex or time-consuming. It consists mainly of using the proper soil, avoidance of overwatering, and regulating the daylight and temperature at various times of the year.
For more information go to: www.denverplants.com/ezine/11-03.htm