Euphorbiaceae       Plant Families with Succulent Species   
    Euphorbiaceae   - Spurges
              The Euphorbiaceae is a very large, widely distributed family 
              including around 300 genera and 7700 species, mainly non-succulent 
              herbs, shrubs and trees found in temperate, sub-tropical and 
              tropical climates. Succulent species are found in the genera 
              Euphorbia, Endadenium, Jatropha, Monadenium, and Pedilanthus, 
              Phyllanthus, and Synadenium, although some of these genera are 
              obsolete and their species now included under Euphorbia. Succulent 
              Euphorbiaceae include diverse lifestyles including caudiciforms, 
              stem succulents, shrubs and trees. Some species are very spiny, 
              resembling Cactaceae at a first glance. 
               
              The Euphorbiaceae have very distinctive small cup-shaped compound 
              flowers. The flower is technically known as a cyathium, consisting 
              of a cup-like involucre containing a single pistil (female flower) 
              surrounded by male flowers, each contributing a single stamen. The 
              cyathium may be surounded by brightly coloured bracts that give 
              the appearance of a large flower. However, some species of 
              Euphorbia have separate male and female plants and some species 
              e.g. Euphorbia obesa may produce a mixture of male, female and 
              bisexual flowers. 
               
              Many species have a milky sap containing latex and irritant toxins 
              including diterpene esters, alkaloids, glycosides, and ricin-type 
              protein toxins, depending on the species. The latex should be 
              washed off the skin without delay and eye contamination avoided at 
              all costs. 
               
              Toxicity of Euphorbia latex 
               
              Euphorbia latex is commercially exploited, with Hevea brasiliensis 
              (rubber tree) the main species grown in plantations throughout the 
              tropics, especially Malaysia and SE Asia. Other important 
              Euphorbiaceae include Ricinus communis (Castor Oil Plant) and 
              Manihot esculenta (Cassava) cultivated for its starchy root and 
              Euphorbia pulcherrima (Poinsettia) widely cultivated in the 
              horticultural trade. 
               
              Cultivation: Most succulent Euphorbias require warmth and full to 
              partial sun. Watering should be very sparing during the winter, 
              especially for caudiciform species unless they can be kept warm 
              and in growth. A very gritty compost suits most species, 
              especially caudiciforms and those with fleshy roots. However, 
              succulent Euphorbias, especially those with leaves, appreciate a 
              dose of high nitrogen fertiliser at the start of their growing 
              season. At other times a balanced fertiliser is suitable. 
              Euphorbia antisyphillitica

              Jatropha dioica

              Pedilanthus macrocarpus 


         

         Left:The candelilla plant (Euphorbia antisyphyllitica) growing at the 
        Langtry visitor center, Texas. The epiphet antisyphyllitica refers to 
        the plant's supposed medicinal properties. The flowers are relatively 
        decorative by the standard of many Euphorbias. This plant is relatively 
        common in the Big Bend country and the Rio Grande valley but in its 
        natural habitat, where water may be scarce and the heat intense, the 
        stems often have a bronzed appearance. 

        The candelilla plant was an important source of candelilla wax, which is 
        still produced in small quantities by boiling large quantities of stems 
        with sulphuric acid, and skimming the wax from the surface of the vat. 
        The wax was used in the manufacture of phonograph records, in cosmetics 
        and as an industrial lubricant. 

        Unfortunately, much of the plant material required for processing is 
        harvested from its native habitat putting pressure on plant populations.
         Left: Dragon's blood, Leatherstem, Jatropha dioica, growing on 
        limestone South of Shafter 
          Left: 
        Pedilanthus macrocarpus, (Slipper Plant) from Sonora and Baja 
        California, growing in the Phoenix Desert Botanical Garden. The flowers 
        attract humming birds. This species is an excellent plant for a 
        container in a warm climate but will not stand any frost.
         Left: Pedilanthus tithymaloides (Devil's Backbone, Slipper Plant) is a 
        tender climbing shrub native to Florida and the West Indies to 
        Venezuela, but established as an invasive weed throughout the tropics. 
        Young stems carry pointed oval leaves. This species is of interest as a 
        potential biofuel crop, as it grows profusely on poor land.

    
        This page is  copyright RJ Hodgkiss 2008.
        Last update: 2nd March 2008. 
