Bauhinia purpureaL. (Fabaceae) is deciduous, tropical and fast growing tree or shrubs which is native to South China and South East Asia. It is also known as orchid tree, purple butterfly tree, purple Bauhinia, Mountain ebony and Geranium tree. In Pakistan, it is locally called Kachnar, Kachan, Karar and Khairwal. It earn its name due to its orchid-like flowers that have butterfly-like appearance. It is naturally occurs in tropical and subtropical regions at elevations from 500-2000 m (exceptionally at 3000 m) of the world. It is commonly found in mixed deciduous forests, valleys, hill slops, savanna, scrublands, along the streams and swamp forests. It can be grown along the road sides, in gardens, parks and distributed areas.
Bauhinia purpurea is grown for ornamental purposes and ideal for containers. It makes a fabulous appearance in house and can be moved to outdoors during summer. It reaches up to 7-10 m (32 ft.) at fast rate. The bark is dark brownish to grayish, smooth and thick. The leaves are 10-15 cm in length and 9-14 cm in width, glabrous and cordate base with acute or rounded apex.The inflorescence is raceme with few flowers which are axillary or terminal. It bears beautiful, pink, fragrant, five petalled and orchid-like flowers. The flowers blooms in early age (2-3 years) during summer. The flower pedicel is about 7-12 mm. The calyx is hairy, petals are oblanceolate,just 3 stamens are fertile, long filaments as petals, stalked ovary, long style and oblique stigma. The fruits are elongated, dehiscent, greenish pods when young while become brown at maturity. Pods are about 15-30 cm long and 1.5-2.5 cm wide.Propagation of Bauhinia can be done through seeds, cuttings, layering and grafting.
Bauhinia purpurea Seeds
Each pod contains about 10-15 seeds which are brown, rounded, flat, compressed, and suborbicular. The thickness of each seed is 1-2 mm while its diameter ranges between 13-16 mm. The seeds ripen between February to May and pods will open naturally in winter weather while some may persist through winter until next flowering season appears. The pods are also collected before dehiscence and dried in sun to extract seeds. Bauhinia purpurea can be propagated easily from seeds. Seeds can be dispersed from pods through water, wind and humans. They germinates on reaching suitable sites under favorable moisture and light conditions while in unfavorable conditions, their radicle dries up. They are rich in Iron (Fe) and Calcium (Ca). Phytochemical screening of seeds yielded phenolic, saponins, flavonoids, tannins and glycosides.
Bauhinia purpurea Seed Oil
The seeds contain about (17.5%) crude oil. The extracted seed oil is rich in bioactive lipid content (99%) followed by glycolipids and phospholipids, respectively. Their fatty composition yields unsaturated fats like linolein (55.34%) and oleic acids (11.84%) and saturated fats like palmitic (17.4%) and stearic acid (11.40%). After oil extraction, the seeds residue is used for animal and poultry feed.
Uses and Benefits of Bauhinia purpurea
The plant have several uses and benefits. A prepared decoction of this plant is a good remedy for ulcers, healing of wounds and injuries. The leaves are crushed to make paste which is used to treat sores and boils. It is also a good source of curing swellings, dropsy, rheumatic pain, cold, cough and asthma. It also shows anticancer property by inhibiting the growth of tumor cells.
The extraction of stems are used as aninternal and external remedy for fractured bones while flowers are used as laxative and flower buds are used to treat dysentery. The bark is used for dyeing, tanning and as an astringentin the treatment of diarrhea. It is also used as an antidote for animal bites. Its juice is useful for women in menstruation cramps and usually taken with honey to treat leucorrhea.
The root-bark extract is mixed with curd to treat hemorrhoids and grind with ginger to treat goiter. The wood is used for fuel and making agriculture implements. The pods and seeds are cooked and eaten by some tribes in India such as Gondas and Kathkors. It is a nitrogen fixing plant which yield gum, helps in soil fertility, control soil erosion and used as fodder.
Sowing instructions for Bauhinia purpurea
- The seeds should be cleaned before sowing.
- After cleaning, seeds are soaked into warm water until they slightly swells up.
- They can be sown in well-drained and sandy compost soil at any time throughout the year.
- After sowing of seeds, thinly covered them with sand or grit and sprinkled water.
- The best temperature for germination is 20-25˚C.
- Seeds germinates within 4-6 weeks but some take longer time.
- Better is to check the container at regular intervals to make sure that the compost does not dry out.
- Seedlings grow rapidly and reaches up to 1 meter within 2 months of germination.
- Then the seedlings will be transferred to open ground or large container.
- If larger plant have to moved, then pruning will be done for easier establishment.
- The plant grows up quickly within 3 years and blooms in 3-6 years.
How to take care of seedlings
- Bauhinia prefers light sandy, medium loamy and well-drained soil.
- It flowers best in dry soil.
- It needs regular watering.
- Better grown on areas which receives at least 1500-2500 mm of rainfall annually.
- It prefers mean annual temperature of 12-21ºC.
- It can be planted inside the house where they get a lot of light. It can also be placed outdoorsin gardens in the sunny position with winter protection.
- It can lose leaves in cold climate. Severe frost kills the seedlings
- Needs occasional pruning to get a uniform shape.
- Use fertilizer after few years for best flower blooming.
- Borers, mites and insects larvae mostly feeds on this specie.
- The plant is also susceptible to leaf spot and leaf scorch diseases.