Ignite your senses at Kew’s Tropical Extravaganza where the Princess of Wales Conservatory is transformed into a sea of exotic plants with amazing floral displays inspired by fire, air, water and earth. 

http://www.kew.org/visit-kew-gardens/tropical-extravaganza-2012/

I’m planning a post on some of the history of genetic research (particularly to do with variation and inheritance) which was carried out using, among other plants and animals, Snapdragons. Some of this research was carried out by William Bateson and “Bateson’s Ladies”, a group of women from Newham College, in Cambridge University. For now here’s a picture of one, more to follow…..

Fig. 1. Poinsettia: The Christmas flower in bloom (click image for larger view).

The poinsettia, Euphorbia pulcherrima Willd., is a member of the family Euphorbiaceae. The genusEuphorbia contains some 1,000 species. It is characterized by a single female flower, without petals and usually without sepals, surrounded by individual male flowers all enclosed in a cup-shaped structure called a cyathium. The showy red, pink, white, or bicolored portion of the plant, popularly referred to as the flower, consists of modified leaves or bracts (Fig. 1).

The poinsettia is a native plant of Mexico and originated in a rather limited region near present day Taxco. Long before the arrival of Europeans, the Aztecs of Central Mexico cultivated the plant and called it Cuetlaxochitl. Because of its brilliant color, the poinsettia was a symbol of purity to the Indians. It was highly prized by both King Netzahualcoyotl and Montezuma, but because of the high altitude climate, the plant could not be grown in their capital that is now Mexico City. The Indians used poinsettia bracts to make a reddish-purple dye. They also made a medicine for fever from the plant’s latex.

During the 17th century, a group of Franciscan priests settled near Taxco. They began to use the poinsettia in the Fiesta of Santa Pesebre, a native procession. Juan Balme, a botanist of the same period, mentioned the poinsettia plant in his writings. He described it as having large green leaves and a small flower surrounded by bracts, almost as if for protection. The bracts, he said, turned a brilliant red. Balme also found the plant flourishing on the slopes and in the valleys near Cuernavaca. Legend has it that the poinsettia became associated with Christmas because the Mexicans regarded it as symbolic of the Star of Bethlehem (62).

Fig. 2. Joel Roberts Poinsett (1779-1851) (click image forlarger view).

Poinsettias were first introduced in the United States in 1825 by Joel Roberts Poinsett (24) (Fig. 2). While serving as the first United States Ambassador to Mexico, he visited Taxco and found the flowers growing on the adjacent hillsides. Poinsett, a botanist of great ability, had some plants sent to his home in Greenville, South Carolina. They did well in his greenhouse and he distributed plants to botanical gardens and to horticultural friends, including John Bartram of Philadelphia. Bartram, in turn, supplied the plant to Robert Buist, a nurseryman who first sold the plant as Euphorbia pulcherrima, Willd. The name poinsettia, however, has remained the accepted name in English-speaking countries.

The modern era of poinsettia culture began with the introduction of the seedling cultivar Oak Leaf (Fig. 3). This cultivar was reported to have been grown originally in Jersey City, NJ, by a Mrs. Enteman in 1923. From 1923 until the early 1960s, all of the principal cultivars of commercial importance were selections or sports from this original Oak Leaf seedling. Earliest production of poinsettia as a cut flower from field-grown plants occurred in what is now Hollywood, California (Fig. 4). Early cultivars were True Red and Early Red. A shift from field-grown stock production to stock production in greenhouses occurred in the 1960s.

Fig. 3. Seedling cultivar ‘Oak Leaf,’ the progenitor of modern poinsettia cultivars (click image for larger view).

Fig. 4. Field production of poinsettia stock plants in Southern California in the mid-1930s (click image for larger view).

Recognition of shorter photoperiod in the flowering of poinsettia (32,60) was the basis for controlled pot plant production and subsequent breeding programs. “During the middle 1950’s, poinsettia breeding programs were initiated at several institutions, including the Pennsylvania State University, the University of Maryland, the USDA Research Center at Beltsville, Maryland, and by a number of commercial horticulture firms including Azalealand, Lincoln, Nebraska; Paul Ecke Ranch, Encinitas, California; Mikkelsen’s, Ashtabula, Ohio; Earl J. Small, Pinnellas Park, Florida; Yoder Brothers, Barberton, Ohio; Zieger Brothers, Hamburg, Germany; and Thormod Hegg & Son, Reistad, Norway. Dr. Robert N. Stewart, Agricultural Research Service of Beltsville, Maryland, used his genetic training to segregate desirable characteristics such as stiff stems, larger bracts, new colors, and lasting qualities. He contributed much in determining the character of mutation forms in poinsettias, and his cooperative efforts have been extremely helpful to the commercial hybridizers” (20).

Fig. 5. Paul Mikkelsen poinsettia (click image for larger view).

“With the introduction of the cultivar Paul Mikkelsen in 1963 (Fig. 5), poinsettias entered a new era. This cultivar, with stiff stems and foliage retention characteristics, provided the trade with the first longer-lasting cultivar of commercial importance” (20). The cultivar Annette Hegg Red was introduced in Norway in 1964 and was quickly followed by a number of sports. The Hegg cultivars introduced an entirely new type of multi-flowered plant to the trade because of their ability to produce from five to eight blooms from a pinch, and because of their ease of production.

In 1988 Eckespoint Lilo was introduced. This was one of the first dark leaf poinsettia cultivars that were early flowering, recovered quickly after unsleeving, and had excellent foliage retention for the consumer. This cultivar required certain cultural techniques to insure good branching. In 1992, Eckespoint Freedom was introduced. Eckespoint Freedom contained the best characteristics of Eckespoint Lilo while branching more consistently for the producers. Today there are over 100 poinsettia cultivars grown commercially, with one cultivar, Eckespoint Freedom representing over 50% of the red market worldwide and 70-75% of that market consisting of poinsettias with red bracts. One final revolution to poinsettia cultivars was the introduction of Eckespoint Winter Rose Dark Red in 1998 (Fig. 6). This cultivar was the first introduction in the “curly” family with dark red incurved bracts and deep dark green incurved foliage. (Adapted from Ecke, et al., 1990. The Poinsettia Manual [20])

Fig. 6. Eckespoint Winter Rose the first cultivar with incurved bracts and foliage (click image for larger view).

Another noted breeding program by Fischer, Hillscheid, Germany, has introduced over 34 poinsettia cultivars to the U.S.A. and Canada over the years. Cultivars of the Color Collection have excellent branching with medium green foliage and compact to medium vigorous growth. The Cortez Family has good color retention and resists epinasty after shipping. Fischer’s Early Red poinsettias consist of Galaxy RedVN, Orion RedVN, and Nova RedVN, adapted for the retail market that is discovering the attractiveness of poinsettias before the Christmas season. Early production makes these poinsettias available for the retail market in early November. The Sonora Family is a mid-season series line with dark green leaves characterized by the oak leaf-shaped foliage, V-shaped habit and exceptional branching. The Sonora Family has good color retention, abundant cyathias during and after shipping, and is available in a variety of colors. Silverstar Marble is Fischer’s newest creation in the Silverstar line. Its beautiful pink and white bicolor bracts sit above soft, green, variegated foliage (Fig. 7). Silverstar Marble has excellent branching, a uniform, compact growth habit, and flowers around the end of November.

Fig. 7. Fischer Silverstar Marble, a pink and white bicolor with variegated foliage (click image for larger view).

Today, poinsettias may be found in many different colors (Fig. 8) as well as product forms from mini poinsettias to large specimen trees and every size in between. Testimony to its success and popularity, the poinsettia is not only the most popular holiday flower, it is the number one flowering potted plant in the United States, with over 65 million plants sold nationwide in 2000 (67). In 2001, more than 120 poinsettia cultivars were under evaluation at university research stations for possible introduction in the future.

Fig. 8. Eckespoint Plum Pudding, the first poinsettia with purple bracts (click image for larger view).