Euphorbiaceae  (The Spurge Family)

Euphorbiaceae, known as the spurge (Plants that have milky sap mostly euphorbias) family, represents a vast group of flowering plants. Referred to as euphorbias in English, this name is derived from the type genus of the family. 

The majority of spurges are herbaceous, there are instances, particularly in tropical regions, where some members are shrubs, trees or even succulents.

The Euphorbiaceae family exhibits a cosmopolitan distribution across the globe. While the highest concentration of species diversity is found in tropical regions, it is noteworthy that the family also encompasses numerous species in non-tropical areas. 

This family is the fifth-largest among flowering plant families, Euphorbiaceae boasts approximately 7,500 species categorized into 300 genera.

1.0Classification of Family Euphorbiacae

2.0General Characteristics of Family Euphorbiaceae

Habit: This family shows a great range of characteristics in vegetative and floral structures. Members of this family are mostly shrubs (for example Jatropa, Ricinus, Euphorbia sps.) or trees (for example Emblica officinalis, Hevea brasiliensis) and rarely herbs (for example Acalypha, Phyllanthus).Euphorbiaceae members display diverse habits, existing as herbs, shrubs, trees, and some even exhibit climbing tendencies. A significant portion of these plants possess laticiferous vessels containing latex.

Root: The roots are typically branched taproots, with tuberous roots being common in certain species.Exceptionally, Manihot has tuberous roots which are rich in starch. Few species of Manihot are edible.

Stem: Stems are erect, branching into woody or herbaceous structures. Phylloclades may be present in some species, and in certain cases, stems can become green and fleshy. The development of spines is a characteristic feature in many stems.

Leaves: Leaves are generally simple, stipulate, and alternate, occasionally opposite. In numerous Euphorbias, leaves are caducous and scaly, sometimes reduced to spines.The leaves are usually alternate or rarely opposite (Choriophyllum) or whorled (Mischodon), simple, entire or deeply palmately lobed (Ricinus and Jatropha) or compound (Bischofia). The leaves are variegated in Croton.

The stipules are usually present and in Jatropha they are represented by ciliate glands. The venation is pinnate or palmate as in Ricinus. In species of Euphorbia, leaves fall off early and photosynthesis is carried by green stems.

Inflorescence: The inflorescence exhibits considerable variation, ranging from cymose to racemose or even complex structures. In Croton, the inflorescence is panicle. In Acalypha, it is catkin and in Jatropha the flowers are arranged in terminal cymose clusters.

Notably, in Euphorbia, the inflorescence undergoes modification into a cyathium, where numerous male flowers surround a central stalked female flower resembling a single flower. Bracts form a cup-like structure around this arrangement.

Each cyathium is surrounded by an involucre of four or five connate bracts and between these large coloured glands a petaloid appendage is present (Splendens).

In the middle of cyathium, there is a single female flower represented by a tricarpellary Gynoecium. In the axil of each bract a number of male flowers are arranged in scorpioid cymes. The oldest flower is nearest to the centre and thus the maturation is centrifugal.Identification characteristics of the family are plants with milky latex and Cyathium (Euphorbia) type of inflorescence.

Flower: Flowers are unisexual, regular, actinomorphic and hypogynous.

Perianth: In a majority of plants, either calyx, corolla, or both may be absent. Occasionally, both calyx and corolla are present, consisting of 4 or 5 sepals or petals with imbricate or valvate aestivation.

Androecium: The androecium comprises one to many stamens, usually equal in number to the perianth leaves. The anthers are dithecous.

Gynoecium: The gynoecium is tricarpellary, syncarpous, with a superior trilocular ovary. Each ovary locule contains one or two anatropous ovules, displaying axile placentation.

Fruit: Fruit is usually three chambered, schizocarpic splitting into three one-seeded cocci. Rarely drupe (Phyllanthus) or berry.

Seed: Seeds are with fleshy endosperm and straight embryo. The seeds are often with a conspicuous caruncle. Seeds are dispersed by birds and animals. Some seeds are also dispersed by explosive mechanism of the capsules.

Pollination: Insects play a crucial role in the pollination process.Unisexual flowers necessitate cross pollination and here pollination is entomophilous taking place with the help of insects. This is due to the presence of brightly coloured glands or bracts, petaloid calyx or nectar. 

3.0Floral Formula and Floral diagram of Family Euphorbiaceae

Ricinus communis (The castor bean)

Jatropha gossypifolia (bellyache bush)

4.0Important Plants of the Family Euphorbiaceae

Examples are as follows-

• Acalypha hispida: Ornamental plant
• Euphorbia geroldii : Gerold's Spurge or Thornless Crown of Thorns.
• Euphorbia maculata : commonly known as spotted spurge.
• Euphorbia pulcherrima: Lalpatta, an ornamental plant.
• Euphorbia hirta: Dudhi, medicinal plant.
• Euphorbia royleana: Thar, used in hedges. Its latex is used as medicine.
• Jatropha curcas: Safed arand, seed oil is used for making soaps, candles.
• Hevea brasiliensis: Rubber, tall tree, bark is used for preparing rubber which is useful in making tyres and inner tubes, and various electrical goods.
• Emblica officinalis: Amla, tree with edible fruits, rich in vitamin C. The wood yields charcoal. Leaves, bark and fruits used in tanning and dyeing.
• Ricinus communis: Arand, small cultivated tree. Castor oil is obtained from seeds it is used in manufacture of transparent soaps, perfumes, varnishes and paints. Also used as a medicine.

5.0Uses and Economic Importance of Euphorbiaceae

The Euphorbia genus is distinguished by the milky latex produced in its subfamilies Euphorbioideae and Crotonoideae. Notably, the rubber tree Hevea brasiliensis, belonging to Euphorbioideae, is a major natural rubber source. 

It's crucial to note that the latex from Euphorbioideae is poisonous. This plant family is renowned for its diverse array of phytotoxins, including diterpene esters, alkaloids, and cyanogenic glycosides. Beyond their toxic properties, certain species of euphorbia within the Euphorbiaceae family hold significant economic importance. 

Examples include cassava (Manihot esculenta), a staple food source. 

The castor oil plant (Ricinus communis), yielding versatile castor oil; 

Barbados nut (Jatropha curcas), with potential industrial applications; 

The Pará rubber tree (Hevea brasiliensis), contributing substantially to the production of natural rubber.

Sap of Excoecaria agallocha causes blistering on contact and temporary blindness if it contacts the eyes. 

However, several plants are poisonous, causing sickness or death if ingested or causing dermatitis if juice contacts the skin. 

The plants such as Phyllanthus emblica, Ricinus communis, Phyllanthus amarus, Jatropha gossypifolia, Mallotus philippinensis are having high medicinal value and are used in several medicinal preparations. 

6.0Information About Euphorbia Maculata

Previously known as: Euphorbia rayturneri, Chamaesyce maculata 

Common Name(s): Prostrate Spurge, Spotted Sandmat, Spotted Spurge.

Spotted spurge is a summer annual weed with a prostrate growth habit that flourishes in warm climates and dies back after frost. It is typically found in sidewalk cracks, roadsides and gardens. 

The small, oblong leaves grow opposite on the stem and have an irregular maroon to purple spot in the center. When stems are broken or injured they emit a milky white sap. The plant forms a thick taproot, which can extend two feet into the soil, and it rarely or never roots at the leaf nodes. The small greenish-white flowers appear in summer and early fall. Even tiny seedlings can flower and set prolific amounts of seed with limited or no dormancy. 

Mowing is ineffective because plants grow so close to the ground. Spurges are well-managed by most preemergence herbicides (Preemergence herbicides prevent germinated weed seedlings from becoming established; either by inhibiting the growth of the root, the shoot, or both) labeled for use.