Asclepiadaceae

The Asclepiadaceae family, commonly regarded as the milkweed family, is a cluster of perennial herbs, shrubs, and trees in rare cases. They consist of 2900 species in 348 genera. Their main distribution is in Africa, South America, Tropical and subtropical regions. 

In India, 250 species are present in 53 genera. We generally see these plants in southern and western parts and the Himalayas. Stapelieae within the Asclepiadaceae family comprises a few succulents like Stapelia. 

Their pollination mechanism is exceptional. The fragrance from the flowers attracts flies easily and leads to pollination.

Hierarchy Classification

• Kingdom: Plantae
• Division: Tracheophyta
• Family: Apocynaceae
• Sub family: Asclepiadoideae

Vegetative Characteristics

Below are the vegetative characteristics of this plant family.

• Habitat: Plants belonging to this family are commonly mesophytes, and some are also xerophytes. 
• Habit: Few of the plants in this family are perennial herbs, Shrubs, or even woody climbers. Some plants of this family are also epiphytic climbers and succulents. 
• Root system: Their root system consists of the taproot system. 
• Stem: Lower parts of the stem are erect, branched, and woody. Bi-collateral vascular plants, which contain whitish liquid similar to milk, are present in branching laticiferous tubes.
• Leaf: Their leaves are intersected and non-stipulated leaves. Xerophytes have leaves that are transformed into spines with a thick waxy covering on them.  

Floral Characteristics

The flowering features of Asclepiadaceae are as below.

• Inflorescence: It is primarily dichasial cyme, occurring from the leaf hypocotyl. Racemose or Umbellatus florescence similar to that in Asclepias and Calotropis. 
• Flower: Flowers belonging to this family are hermaphrodite, bracteates, hypogynous, bracteolate, actinomorphic, and pentamerous. 
• Calyx: It comprises five sepals that join together to form a small tube. It shows imbricate or valvate aestivation.
• Corolla: It has 5 petals merged, which may be rotated or funnel-shaped. It displays valvate or twisted aestivation.
• Androecium: It comprises five epipetalous stamens inserted at the foot of the corolla tube. Free or joined filaments form a tube around the style.
• Gynoecium: Ovaries of the two carpels of the gynoecium are free. The ovary of each carpel has a single locus with a single placenta and marginal placentation. 
• Pollination: The flowers show entomophily or pollination by insects. This family has a unique pollination mechanism.
• Fruit: Two sacs that are either close together or divergent are present. They may vary in shape and texture.
• Seed: The family has flat seeds with a terminal cluster of white long silky hair. They have dense endosperm and a large embryo.

Asclepiadaceae Family Plant List

Some important plants of this family are as follows:

1. Milkweed (Asclepias curassivica)
2. Butterfly weed (Asclepias tuberose)
3. Rubber wine (Cryptostegia Grandiflora)
4. Indian Sarsaparilla (Hemidesmus indicus)
5. Wax plant (Hoya carnosa)
6. Blue milk weed (Oxypetalum caeruleum)
7. Carrion flower (Stapelia gigantean)
8. Indian Impecacuanha (Tylophora indica)

Economical Uses

Let us look at the uses of the plants belonging to Asclepiadaceae.

• We obtain heat-trapping material for lining jackets and other winter clothes from the hair of the seeds.
• Asclepias Curassavica (Milkweed) and Stapelia (carrion flower) make up the decorative plants of this family.
• The Tylophora Indica (Indian Impecacuanha) species’ roots are used in the form of medicine to treat respiratory diseases.
• The dried roots of Hemidesmus indicus (Indian Sarsaparilla) are useful as blood cleansers in chronic rheumatism, urinary diseases, and skin diseases.
• People believe Gymnema Sylvestre has many medicinal properties. We can use it as a stimulant, laxative(treat constipation), and diuretic(affects kidney to produce more urine). 

Conclusion

The members of the Asclepiadaceae family are mostly milky weed plants with many uses in tanning industries, medicines, ornaments, and winter wear. They are known for their outstanding mechanism of pollination, which is entomophily. We can find them in Africa, South America, tropical and sub-tropical regions (including India).