# Tangedu Flower in English: Tanner's Cassia, Telangana State Flower

URL: https://rasatheory.in/blog/tangedu-tanners-cassia/
Published: 2026-10-04
Updated: 2026-10-25

Answer: In English, tangedu (తంగేడు, also spelled thangedu) is called tanner's cassia or avaram senna. Its scientific name is Senna auriculata. It is the state flower of Telangana and one of the flowers stacked into Bathukamma. Its bark is rich in tannins, which gave it the name tanner's cassia.

In English, tangedu (also spelled thangedu) is called tanner's cassia or avaram senna, and its scientific name is *Senna auriculata*. It is the [state flower of Telangana](https://www.telangana.gov.in/about/state-symbols/). Its yellow flowers go into Bathukamma, and its tannin-rich bark once supplied India's tanneries. The traditional medicinal use is real, but the tested evidence is mostly laboratory and animal work.

## What is tangedu called in English, and what is its scientific name?

Tangedu is the Telugu name for *Senna auriculata* (L.) Roxb., a much-branched shrub of the legume family, Fabaceae, native to the Indian subcontinent and Myanmar. [World Flora Online](https://www.worldfloraonline.org/taxon/wfo-0000184148) treats Senna auriculata as the accepted name and Cassia auriculata as a synonym, which is why both appear on labels and in papers.

Tangedu is not the laxative senna. The [Ayurvedic Pharmacopoeia of India](https://archive.org/details/AyurvedicPharmacopoeiaOfIndiaAllVolume) lists that drug as Svarnapatri, the leaf of *Cassia angustifolia*, a different species.

## What does the tangedu plant look like?

Tangedu is a much-branched shrub with smooth cinnamon-brown bark, pinnate leaves and large bright yellow flowers, [nearly 5 cm across](https://en.wikipedia.org/wiki/Senna_auriculata), carried in short upright clusters near the top. The fruit is a flat, pale-brown pod 7.5 to 11 cm long holding 12 to 20 seeds. It grows in the dry regions of India and Sri Lanka.

The yellow flower is the part in Bathukamma and in most flower-based preparations. The plant has many local names, which the questions at the end of this page list.

## Why is tangedu the state flower of Telangana?

Tangedu is the state flower of Telangana because it is woven into Bathukamma, the festival of flowers. The state government's symbols page says [tangedu flowers are used during Batukamma](https://www.telangana.gov.in/about/state-symbols/) and calls it the most appropriate choice. Bathukamma runs for [nine days during Navratri](https://ecoheritage.cpreec.org/bathukamma-the-floral-festival-of-telangana/).

Men traditionally gather wild flowers from open land, including tangedi, to be stacked by the women into a layered arrangement shaped like a temple tower. For many people in Telangana, the colour of tangedu is simply the colour of that festival.

## Why is it called tanner's cassia?

Tangedu is called tanner's cassia because its bark was a major tanning material. The bark of *Senna auriculata* [contains 15 to 22 percent tannin](https://plantuse.plantnet.org/en/Cassia_auriculata_(PROSEA)) on a dry weight basis in plants over three years old. Tannins bind to proteins, which is the chemistry that turns raw hide into leather.

The same source notes that avaram bark gave a buff-coloured leather of good quality, and that production was once as high as 50,000 tonnes of dried bark a year, centred on Madras, Hyderabad and Mysore. The English name describes a use of the bark, not the flower.

## What are the traditional uses of tangedu?

Tangedu has a long place in Ayurveda, Siddha and Unani practice. A 2021 review lists traditional uses for [diabetes, asthma, rheumatism, dysentery and skin disease](https://pmc.ncbi.nlm.nih.gov/articles/PMC8423098/), and notes that dried flower powder is used to clean the hair. A popular belief also holds that the flower tea [improves complexion](https://en.wikipedia.org/wiki/Senna_auriculata).

That tradition is a large part of why the flower turns up in botanical soaps. Tradition records what people have done, and it is a fair reason to be curious. It is not the same as a tested result.

## Which parts of the tangedu plant are used?

Almost every part of the plant has a recorded use, and the part matters. The 2021 review notes that [flowers, leaves, seeds, bark and roots](https://pmc.ncbi.nlm.nih.gov/articles/PMC8423098/) have all been used in traditional medicine, while the bark was the tanning material. A 2018 rat study compared bud and flower directly, because the two [differ in their compounds](https://pubmed.ncbi.nlm.nih.gov/30372851/).

Findings for one part do not carry over to another. The melanin result above came from seeds, and the hair-cleaning use is for dried flower powder. A soap made with flowers cannot borrow results from the seeds, the bark or the roots.

## What compounds does tangedu contain?

The flowers contain tannins, polyphenols, alkaloids, glycosides, saponins, terpenoids and anthraquinones, including aloe-emodin, according to the [2021 review](https://pmc.ncbi.nlm.nih.gov/articles/PMC8423098/). These compounds are behind most laboratory findings. A compound list is not a health benefit, because it says what is present and not what it does on skin.

Anthraquinones are also the colouring compounds in another Indian botanical, [manjistha](/blog/manjistha-in-soap/).

## What does the scientific evidence say about tangedu?

Most of the evidence is preclinical, meaning laboratory and animal work. The 2021 review says no clinical data were available for its antidiabetic effect and that [human studies had not been performed](https://pmc.ncbi.nlm.nih.gov/articles/PMC8423098/) for its liver-protective effect. Calling it proven for any condition would go beyond what has been tested.

Examples show how far the work goes. A 2018 rat study tested [bud and flower extracts against diabetes](https://pubmed.ncbi.nlm.nih.gov/30372851/). A 2019 cell study found that compounds from the seeds, not the flowers, [reduced melanin production](https://pubmed.ncbi.nlm.nih.gov/30847755/) in mouse melanoma cells. A 2024 laboratory study found that a flower extract [inhibited some bacteria](https://pubmed.ncbi.nlm.nih.gov/38882808/) in a dish.

None of these tests a soap on human skin. If you have a skin condition, a dermatologist is the right person to ask.

**Why a botanical soap should not make medical promises.**
India's Cosmetics Rules, 2020 state that no cosmetic may [claim anything false or misleading](https://cdsco.gov.in/opencms/resources/UploadCDSCOWeb/2022/cos_rules/Cosmetics%20Rules%202020.pdf). A soap that says tangedu treats a skin condition is claiming more than the studies above show.

## Is tangedu safe?

The safety picture is mixed, and it mostly concerns swallowing the plant, not washing with it. The 2021 review says preclinical toxicology studies found the plant safe but that clinical studies are still needed. Other work raises cautions. A [Sri Lankan screening](https://pubmed.ncbi.nlm.nih.gov/7311596/) found pyrrolizidine alkaloids in *Cassia auriculata*, and rats fed material from it developed liver lesions.

The reference work PROSEA also notes pyrrolizidine alkaloids that are [suspected of hepatotoxic properties](https://plantuse.plantnet.org/en/Cassia_auriculata_(PROSEA)). In rats, flower tea raised steady-state [theophylline levels by 32.5 percent](https://pubmed.ncbi.nlm.nih.gov/15663295/). We found no study of rinse-off soap, so nothing here shows harm from a bar either.

## What does tangedu do in a soap?

Tangedu goes into soap as a botanical addition, usually an oil infused with the flowers or a dried flower powder stirred into the batter. We found no study of tangedu inside a soap bar, so its effect there is unproven. Any mildness comes mainly from the formulation, meaning the oils, the [superfat](/blog/superfat-and-lye-discount-explained/) and a full [cure](/blog/how-long-soap-needs-to-cure/).

To judge the bar, look at how it was made. The [label guide](/blog/how-to-read-a-soap-label/) shows how to tell real [cold process soap](/blog/cold-process-vs-melt-and-pour-vs-hot-process/) from a decorated base. The label may name the plant as Senna auriculata, Cassia auriculata or tangedu.

## The short version

Tangedu is *Senna auriculata*: tanner's cassia, avaram senna, Telangana's state flower and a Bathukamma flower. The English name comes from tannins in its bark. It has a long traditional history in medicine and a short list of tested results, mostly in the laboratory or in animals. Both are worth knowing.

## Frequently asked questions

### What is tangedu called in English?

Tangedu is called tanner's cassia or avaram senna in English. Its scientific name is Senna auriculata, and older books use Cassia auriculata. Thangedu puvvu, a common spelling in searches, simply means tangedu flower in Telugu.

### Is tangedu the national flower of Telangana?

Tangedu is the state flower of Telangana, the official flower chosen by the state government. A state has a state flower rather than a national one. The national flower of India is the lotus.

### What are the other names for tangedu?

Tangedu is the Telugu name. The same shrub is avaram or avarai in Tamil, avarike in Kannada, tarwar in Hindi and avartaki in Sanskrit. In English it is tanner's cassia or avaram senna, and older labels use the botanical name Cassia auriculata.

### Is tangedu the same as the senna used for constipation?

No. The laxative Indian senna in the Ayurvedic Pharmacopoeia of India is Svarnapatri, the leaf of Cassia angustifolia. Tangedu is Senna auriculata, a different species, so one should not be assumed to act like the other.

### Is tangedu flower tea safe to drink?

We found no human safety trial of the tea. Rat studies found that the flower tea raised blood levels of the drugs theophylline and carbamazepine, and one screening found pyrrolizidine alkaloids in the plant. Anyone taking prescription drugs should ask a doctor before drinking it.

### Can tangedu lighten skin?

Traditional belief says the flower tea improves complexion, but no human study confirms it. The only skin-colour finding we found is a laboratory result on seed compounds in mouse cells, which does not show an effect on people or in a soap.


## Sources

- Government of Telangana, State symbols: https://www.telangana.gov.in/about/state-symbols/ (supports: Tangedu (Tanner's Cassia) as the state flower of Telangana, associated with the Bathukamma festival.)
- World Flora Online: Senna auriculata (L.) Roxb.: https://www.worldfloraonline.org/taxon/wfo-0000184148 (supports: Senna auriculata as the accepted name, Cassia auriculata L. as a synonym, and the native range from the Indian subcontinent to Myanmar.)
- Nille et al. (2021), Ethnopharmacological, phytochemical, pharmacological and toxicological review on Senna auriculata, Frontiers in Pharmacology: https://pmc.ncbi.nlm.nih.gov/articles/PMC8423098/ (supports: Traditional use in Ayurveda and Siddha, names in several Indian languages, preclinical findings, and the lack of human clinical data.)
- PROSEA (Pl@ntUse): Cassia auriculata: https://plantuse.plantnet.org/en/Cassia_auriculata_(PROSEA) (supports: Bark tannin content of 15 to 22 percent, use in tanning, former production volumes, and pyrrolizidine alkaloids suspected of hepatotoxic properties.)
- Arseculeratne et al. (1981), Pyrrolizidine alkaloids and hepatotoxic properties in some traditional medicinal herbs of Sri Lanka, Journal of Ethnopharmacology: https://pubmed.ncbi.nlm.nih.gov/7311596/ (supports: Pyrrolizidine alkaloids detected in Cassia auriculata, and liver lesions in rats fed material from the plant.)
- Thabrew et al. (2004), Cassia auriculata tea and theophylline blood levels in rats, Drug Metabolism and Drug Interactions: https://pubmed.ncbi.nlm.nih.gov/15663295/ (supports: Flower tea raised steady-state theophylline levels by 32.5 percent in rats.)
- Wang et al. (2019), Inhibition of melanin production by compounds from Cassia auriculata seeds, Journal of Natural Medicine: https://pubmed.ncbi.nlm.nih.gov/30847755/ (supports: Seed compounds reduced melanin production in mouse melanoma cells in the laboratory.)
- Ayurvedic Pharmacopoeia of India, Part I (digitised, Internet Archive): https://archive.org/details/AyurvedicPharmacopoeiaOfIndiaAllVolume (supports: Svarnapatri, the laxative Indian senna, is the leaf of Cassia angustifolia, a different species from tangedu.)
- Nambirajan et al. (2018), Antidiabetic activity of bud and flower of avaram senna in diabetic rats, Biomedicine and Pharmacotherapy: https://pubmed.ncbi.nlm.nih.gov/30372851/ (supports: Bud and flower were tested for antidiabetic activity in rats, not in people.)
- Rahman et al. (2024), Antimicrobial activity of Senna auriculata flower extract, Journal of Pharmacy and Bioallied Sciences: https://pubmed.ncbi.nlm.nih.gov/38882808/ (supports: A methanolic flower extract inhibited Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans in a laboratory assay.)
- Cosmetics Rules, 2020 (CDSCO), rule 36: https://cdsco.gov.in/opencms/resources/UploadCDSCOWeb/2022/cos_rules/Cosmetics%20Rules%202020.pdf (supports: No cosmetic may claim to convey any idea that is false or misleading to the intending user.)
- CPREEC, Bathukamma: the floral festival of Telangana: https://ecoheritage.cpreec.org/bathukamma-the-floral-festival-of-telangana/ (supports: Tangedi among the wild flowers gathered by men for Bathukamma, which is celebrated over nine days during Navratri.)
- Wikipedia: Senna auriculata: https://en.wikipedia.org/wiki/Senna_auriculata (supports: Local names in several languages, and the belief that flower tea improves complexion.)