Indigo vs. False Indigo: Key Differences

Written by Mary Mettle
Updated: October 25, 2022
© iStock.com/magicflute002
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Indigo and false indigo are two very different perennial plants that are extremely valuable to humans. Despite their names, they they differ significantly in terms of taxonomy, appearance, classification, history, usage, and other key criteria.

This article will explain the differences between these plants as well as their uses.

True IndigoFalse Indigo
Scientific NameIndigofera tinctoriaBaptisia australis
SizeCan grow up to 3 feet in height and 3 feet wide
The seed pods can be 2 inches long
Can grow up to 1 meter long
Seed pods can be 2.5 inches long
OriginAfrica, China, and tropical regions of AsiaCentral and Eastern North America
ColorThey produce white or pink flowersFlowers are blue or violet
UsesUsed as poison antidote
Used for premature hair fall off
It treat canker sores
Helps with dog bites
Helps to remove worms from gums and teeth
Reduces body temperature
It boost your appetite
Treating tonsils
Treats larynx infection
Eliminates mucus from your body

True Indigo vs. False Indigo: Description

True indigo belongs to the bean family. The plant is commonly identified by its light green pinnate leaves, which cluster between four and seven sets. Like most members of the bean family, this plant can reach up to 3 feet in height and 3 feet wide. This plant forms seed pods up to 2 inches long after the petals have fallen off.

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More interestingly, true indigo produces either white or pink flowers. Most people assume that the indigo dye, which was used to dye blue jeans and other clothing in the past, comes from the plant’s flowers. This is inaccurate. The fact is that fermentation of the leaves containing the organic indican chemical produces the dye. During the fermentation process, the indican chemicals transform into a bluish-purple indigotin color.

Twig of true indigo plant
Green twig of fresh Indigofera tinctoria, also called true indigo

©iStock.com/PicturePartners

Blue false indigo, falls under a group of long-lived perennial plants. This wild indigo has an upright stalk and three-parted compound leaves. And it can reach a height of just over 3 feet. Unlike true indigo, the blue false indigo plant’s flowers are violet and blue colored. Moreover, its 2.5-inch long seed pods are black and have sharp pointed tips. The plant also acts as a host to many species of butterflies.

False indigo has very deep tap roots, which look like black wood when dug up. If you break the roots or the glabrous stems, the herb will secrete some sap that turns dark blue when exposed to air.

As it matures during the first two seasons, it blooms increasingly with dense clusters of brightly colored flowers and becomes generously showy. With attractive bluish-green foliage, it is an excellent backdrop for other flowering plants. In case you decide to grow this herb, maintenance is relatively easy, plus it will only take two years to start blooming.

blue false indigo
False indigo plants create clusters of showy violet or blue flowers.

©iStock.com/magicflute002

True Indigo vs. False Indigo: History

True indigo is a tropical shrub that was the primary source of the blue dye commonly identified as indigo. According to most historians, this is a plant native to some parts of Africa, China, and tropical regions of Asia.

Since the shrub has been in cultivation since 4,000 BCE, it’s challenging to pinpoint the exact location of its origin. That’s mainly because the introduction that took place across the globe during that era were before the period of keeping good records. During the 18th century, the shrub became a major cash crop in the Southeastern US.

False indigo was used as a substitute for the costly true indigo. By 1724, false indigo was already introduced to Britain. In the 1700s, a naturalist from Williamsburg, John Clayton, listed false indigo species in the Philadelphia Nurserymen catalog.

The popularity of false indigo was also fueled by the blue hue it produced, which was preferred for clothing. Because of its value, the English government encouraged massive cultivation of this plant in its colonial territories. Generally, after establishing this drought-tolerant perennial plant, its blossom is super attractive. And the foliage makes an excellent subject for a wild garden or a flower border.

True Indigo vs. False Indigo: Uses

True Indigo Uses

Historically, true indigo has been administered for a wide variety of medicinal and cosmetic reasons. Please note: A-Z Animals does not recommend plants or herbs for medicinal or health use. We present the following information for academic and historical purposes only.

  • Antidote for poison
  • Treatment for urinary problems
  • Topical treatment for hair loss
  • Hair color
  • Treating canker sores
  • Treating dog bites — Historically, true indigo was administered to individuals who were bitten by rabid dogs. This is not an effective treatment for rabies.
  • Remove worms from teeth and gums
True indigo powder
Historically, true indigo powder has been used as a folk remedy for a wide variety of ills.

©iStock.com/Shamil

Uses of False Indigo

Like true indigo, false indigo has been used in folk medicine. Again, please note that A-Z Animals does not recommend plants or herbs for medicinal or health use. We present the following information for academic and historical purposes only.

  • Reduce fever, congestion, and body aches
  • Boost appetite and improve digestion
  • Treat leucorrhea
  • Treat tonsilitis, the common cold, upper respiratory tract infections, mucous membrane Inflammation, and fever
  • Eliminate mucus from the body
  • Treat throat, ear, and nose infections
  • Treat infection of the larynx
  • Treat pharyngitis
  • Treat influenza and diphtheria
  • Heal common skin conditions, wounds, and cuts

Historically, non-medicinal uses included:

  • Repelling flies by keeping it near farm animals
  • Using the seed pods as decorations in flower arrangements
  • Using it as blue dye instead of the pricey true indigo

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blue false indigo
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About the Author

Mary Mettle is a freelance writer who offers ghostwriting, copywriting, and blogging services. She is passionately interested in ways we can learn from our experiences to become more authentic versions of ourselves. The snake plant has always been her favorite plant, not only because it can survive without water for a long time but also because it can freshen the air.

FAQs (Frequently Asked Questions) 

Can false indigo spread?

False indigo (baptisia australis) is a plant that dislikes being moved. Once planted and well established, their roots can grow very deep into the ground, up to lengths of 11.48 feet. With deep roots like these, the plant is practically drought-tolerant.

Can you grow the indigo shrub in a pot?

Yes, it is possible. However, this will limit its growth. If you must use a pot, ensure it’s at least 6 inches deep.

Is it advisable to cut false indigo during the fall?

When cutting, only aim for the stems. Early spring, fall, and winter are when you can cut its branches to the ground before the new shoot grows.

Are indigo plants poisonous?

According to research on livestock, some are very poisonous, especially the Indigofera ones. Common symptoms of indigo poisoning include; general body weakness, paralysis, spasms, and even death.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.

Sources
  1. University of Maryland Extension, Available here: https://extension.umd.edu/resources
  2. IPL, Available here: https://www.ipl.org/essay/Essay-On-Indigo-PJBJ4YA35U
  3. Research Gate, Available here: https://www.researchgate.net/profile/Zoltan-Botta-Dukat/publication/311796497_The_most_important_invasive_plants_in_Hungary/links/585ae02b08ae329d61f1480f/The-most-important-invasive-plants-in-Hungary.pdf#page=56
  4. Online Library, Available here: https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.9290
  5. Plant Path, Available here: https://plantpath.osu.edu/sites/plantpath/files/imce/images/NativePlants/BlueWildIndigo.pdf