Euphorbia

When walking in the countryside at this time of the year, the plants that stand out most are the Euphorbia's. The three photos above are the most common Euphorbias in the area. From top to bottom: Euphorbia characias, Euphorbia cyparissias and Euphorbia serrata.

Going down to the coast there are two distinct Euphorbias, Euphorbia dendroides (Tree spurge) a rounded shrub up to 2m tall:

and Euphorbia paralias:

The name Euphorbia is named after "Euphorbus", a Greek physician to King Juba II of Numidia (50-52 BB-23AD). He wrote about a cactus like plant that was a powerful laxative. King Juba (married to the daughter of Anthony and Cleopatra) subsequently named this plant after his physician. When "Carl Linnaeus" created his system of plant classification, he assigned the name Euphorbia to the entire genus in the physician's honour.

The Euphorbias are unique in the plant kingdom. What we think is a flower is called a Cyathium. The Cyathium includes the male and female flowers with their specific parts, the nectar glands and the Bracts (Bracteole if they are small).



The Bracts, depending on the species can be very colourful as in Euphorbia pulcherrima (Ponsettia):

and in Euphorbia griffithii:

Euphorbia is one of the most diverse genera in the plant kingdom. They belong to the Euphorbiaceae family which includes 2008 species. The Genus Euphorbia is found in tropical and subtropical regions of Africa and the Americas, but also in the temperate zones worldwide. The plants vary, in most cases the female and male parts are on the same plant, but this is not always the case as for example in Euphorbia obesa.

The "succulent species" come mostly from Africa, America and Madagscar. Euphorbia obesa originates in South Africa, the female flowers are on the left plant, the male flowers on the right one:

Euphorbia myrsinitis originating from S. and E. Europe to Turkey and C. Asia, does very well in our gardens. It is a succulent very suitable to a rockery:

Some resemble more a Cactus as in Euphorbia resinifera, it is only when the this Euphorbia is in flower that we can recognise it as a Euphorbia. Euphorbia resinifera was used in poultices and creams to create a longlasting prickling sensation to the skin. Nowadays considered too dangerous to use.

Another Euphorbia type cactus seen often inside the home, is Euphorbia milii from Madagascar:

Euphorbia "Diamond Frost" is a relatively new cultivar. A wonderful annual that gives you pleasure from May to the frost.

The common name for Euphorbia is "Spurge". This name derives from the Middle English/Old French word "Espurge" (to purge) due to the use of the plant's sap as a purgative. Most spurges contain carcinogenic, highly irritant, diterpene esters and are strong purgatives. All Euphorbias are toxic if eaten. The sap (latex) is a serious skin and eye iritant.

The only Euphorbia still used in herbal medicine is Euphorbia hirta, it is ester free and regarded worldwide as a safe, effective herb. Internally it is used for asthma, bronchitis, emphysema, nervous cough, catarrh, hay fever, and amoebic dysentry. Externally for burns and warts.

Bibliography: RHS: Encyclopedia of Herbs; Wikipedia: Euphorbia; Fytotherapeutisch compendium: J. van Hellemont; RHS: A-Z Encyclopedia of Garden Plants; The Pharmaceutical Press: Herbal Medicines.

Poinsettias

As the Christmas season approaches, the Poinsettias are for sale everywhere. Quite a few of us buy them every year. I tend to buy them just before Christmas, if I buy them earlier, I end up with a plant that has a few leaves at the top and the rest of the stalk is bare. What can we do to keep them looking nice, for a longer period.

First of all a Poinsettia, the Latin name is Euphorbia pulcherrima, is a native of southern Mexico and the north of Guatemala. A tropical area of the world. The first time I saw them growing in the wild was on the way to Fraser's Hill in Malaysia (a colonial hill resort), much like we see Oleanders growing in the central reservation here in the Var. They must have been imported into Malaysia during the colonial period. It was quite stunning, rows and rows of them.

The red bracts (modified leaves) and not the flowers make the plant so attractive. The flowers are in the centre of the red bracts. Nowadays through hybridisation Poinsettias range in colour from red to white. When choosing a Poinsettia make sure the flowers in the centre of the bracts are still closed, which means the plant is at the beginning of its cycle.

Here follow a few tips:

During transport from shop to home make sure the plant is well wrapped, Poinsettias do not like big difference in temperature.

Place the Poinsettia near a sunny window, room temperature max. 22 degrees C, dropping to 15 degrees C. at night. Avoid too much variations in temperature. Do not let the leaves touch the windows.

Only water the plant whenever the surface feels dry to the touch. Water until it drains out of the bottom, but do not let it stand in water.

In nature Poinsettias grow in a tropical climate, they like humid conditions. If your living room is too dry, you might find you have to water the plant daily.

After Christmas care:

At the end of the winter the coloured bracts will drop. Keep watering as mentioned above till March.

In April, gradually decrease the watering, allow the plant to get dry between watering periods. After about 2 weeks of the drying out period, move it to a cool spot, never less than 15 degrees C.

In mid May, cut the stems back to about 4 inches and repot in a slightly larger container, with new soil. Water it well. Place it in room near the window with temperatures around 22 degrees C. Continue watering when plant feels dry. Once new growth appears, begin fertilising.

In June the Poinsettia can be placed outside in a shaded location.

In July pinch back the new growth by 2.5 cm, to encourage the plant to branch out. Do the same in August. When the weather gets colder bring the plant inside and place it near a window.

In October to create the colourful bracts the plant needs to be kept in total darkness from 5pm to 8am each day for 8 weeks. During the day place the plant again near a window and continue with the normal watering and fertilising.

End of November, stop creating the total darkness, place the plant near the window.

December, stop fertilising about December 15th and treat it as you did when you first bought it.

Bibliography: Rustica, About.Com - Poinsettias