"Karan" refers to the plant commonly known as oleander (Nerium oleander), a shrub or small tree prized for its vibrant, fragrant flowers and glossy, dark green leaves, often used in landscaping, but it's important to note that all parts of the plant are highly toxic. 

Here's a more detailed description of the Karan plant:

Botanical Characteristics:

Scientific Name: Nerium oleander 

Common Names: Oleander, Kaner 

Growth Habit: Upright, rounded evergreen shrub or small tree, reaching 2-6 meters (7-20 feet) tall. 

Leaves: Dark green, glossy, thick, and leathery, arranged in pairs or whorls of three along the stems. 

Flowers: Showy, fragrant, terminal cymes (clusters) of 5-petaled, funnel-shaped flowers in shades of white, pink, red, or sometimes purple. 

Fruit: Long, narrow pair of follicles that split open at maturity to release numerous downy seeds. 

Toxicity: All parts of the plant are highly toxic and potentially fatal. The sap can cause contact dermatitis, and even burning the plant can be injurious. 

Uses: Commonly used as an ornamental plant in landscaping, especially in coastal areas due to its salt tolerance. 

Other Information:

Blooming Season: Typically blooms in spring and summer, with sporadic blooms throughout the year. 

Hardiness: Tolerant of heat, drought, wind, and poor soil. 

Pests and Diseases: Relatively free of serious problems, but aphids, caterpillars, mealybugs, and scale can be occasional pests. 

Other Names: In some regions, it may be known as "Kaner" or "Karan Flower". 

Related Plants: The yellow oleander (Cascabela thevetia) is another species in the same family (Apocynaceae) that is also known for its toxicity.