Verbenaceae

The Verbenaceae family, also known as vervain, consists of plants mainly from tropical regions like herbs, shrubs, trees, etc. Some of the flowers also contain an aromatic smell. It consists of 800 species distributed in 32 genera. This family is very similar to the Lamiaceae family for plant parts like corolla and calyx. These plants generally belong to tropical and subtropical regions. In India, 125 species are distributed in 21 genera.

Hierarchy Classification

Kingdom: Plantae

Division: Tracheophyta

Order: Lamiales

Family: Verbenaceae

Vegetative characters

• Habit- perennial or annual herbs generally and in some cases halophytes also.
• Root system- has a tap root system; the roots are highly branched and pneumatophores in some exceptional cases.
• Stem: the stem is straight where some branches have spines on them. It can be herbaceous and woody.
• Leaf: pinnately compound or palmately compound having no stipules.

Floral characters

• Inflorescence: Racemose florescence with colored bracts.
• Flower: The flowers belonging to this family are hermaphrodite, hypogynous, bracteolate, zygomorphic, and pentamerous or tetramerous. 
• Calyx: It has sepals that have 5 lobes, and the sepals are joined together in a bell-shaped or tubular form; valvate aestivation is seen, and the ovary is inferior.
• Corolla has five petals joined together, which may be rotated or funnel-shaped. Valvate or twisted aestivation is seen. It has Petals with 5 or 4 lobes where the petals are joined together, but the petals are unequal in a tubular or cylindrical shape, imbricate aestivation is seen, and the ovary is inferior.
• Androecium: has 4 stamens of unequal length, and the 5th stamen, if present, is sterile or is absent. The stamens are embedded in the corolla. The androecium is dithecous with free filaments and an anther. The dehiscence of the anther longitudinally takes place.
• Gynoecium: Bicarpellary Gynoecium with joined carpels. Each carpel’s ovary is bilocular in the early phase but divides into 4 or more with false septa with axile placentation or central placentation.
• Pollination: The flowers show entomophily or pollination by insects. 
• Fruit: The fruit is rarely a schizocarpic capsule covered by calyx.
• Seed: the seed has a straight embryo and is non-endospermic.

Important plants of the Family

1. Citharexylum spinosum fiddlewood
2. Clerodendrum magnificum, 
3. Clerodendrum myricoides blue glorybower
4. Clerodendrum quadriloculare
5. Clerodendrum thomsonae bleeding heart
6. Duranta repens golden dewdrop
7. Gmelina philippensis
8. Holmskioldia sanguinea cup and saucer
9. Lantana camara
10. Petrea volubilis sandpaper vine
11. Stachytarpheta urticifolia
12. Tectona grandis
13. Verbena bonariensis
14. Verbena gooddingii
15. Verbena litoralis seashore vervain
16. Vitex rotundifolia, beach vitex.

Economical Uses

• It is instrumental in obtaining timber as the wood of the Tectona grandis species is very hard. Wood is useful in making musical instruments, ships, boats, and excellent quality furniture.
• It has Medicinal properties as well, like the roots of Clerodendron are used to treat respiratory diseases like asthma and cough in some cases. Leaves of Lantana camara are injected in tetanus and rheumatism. The leave’s juice of Gmelina Arborea is used in gonorrhoea, cough, and ulcers.
• Some of the species also produce essential oils.
• The bark of some species is also used in the tanning industries.
• The leaves of Vitex negundo serve as a febrifuge. The branches of this plant are kept over stored grains to keep off insects.
•  Few species of this family are often used for ornamental purposes.

Closeness With Other Families

• The family shows relatedness with Lamiaceae in the corolla and calyx. 
• It has an affinity with Boraginaceae in the fluorescence, calyx, and fruit. 
• It bears a relationship with Acanthaceae.

Conclusion

Members of the Verbenaceae family, also known as the vervain family, consists of plants mainly from the tropical regions like herbs, shrubs, trees, etc. Some of the flowers also contain an aromatic smell. It consists of 800 species distributed in 32 genera. This family is very similar to the Lamiaceae family for plant parts like corolla and calyx. They are also of great economic importance in tanning industries, medicines, ornaments, decorative purposes, and producing excellent quality timber.