Impatiens denisonii is a scapigerous herb species of the Balsaminaceae family, which is found only in the Western Ghats in South India. It is among the rarest of the eighteen Impatiens species which are endemic in the Nilgiri Hills. It was very abundant and considered among the most beautiful plants in the Nilgiri Hills.
This plant has numerous pink or purple flowers. The leaf base is deeply 2-lobed with a broad sinus. The scape and pedicels are very long and slender. The wings are 3-partite bearded on the inner face. The lateral segment has a filiform appendage enclosed in the long recurved spur.
The leaves are ovate cordate with bristly crenatures with numerous weak hairs above and glabrous below. Petioles are generally shorter than the leaves. Scapes much longer than the leaves. Bracts are small and ovate, pedicels are 1 inch (25 mm) long. Sepals are small and ovate. The vexillum is rather large broadly ovate, vaulted and has three broad spreading lobes with a dense tuft of petaloid hairs above the conjunction of the lobes. It has a long filiform appendage which is entirely hidden in the spur and extends its whole length. Spur is a very long recurved glabrous capsule. Seeds are numerous and small.
I. denisonii is found in grasslands and along hedges and in wastelands of the Nilgiri Hills. It was very abundant on rocks and trees of the western slopes of the Nilgiris along the Sispara Ghat at elevations of 900 metres (3,000 ft) to 1,500 metres (4,900 ft).
In 2002, it was rediscovered by Tarun Chhabra and other researchers of the Edhkwehlynawd Botanical Refuge (EBR) of Udhagamandalam (Ootacamund). This team noticed that several native species of wild balsams were seldom seen in the field. For three years of ongoing botanical studies they made field trips during each August–September period when the balsams are in bloom. They sighted the I. denisonii only during their third year of searching. This was the first scientific collection of the species since British naturalist Richard Henry Beddome first documented it in 1862.
- Impatiens denisonii Photo
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- The endemic Nilgiri Impatiens species are: (11 Listed by Chhabra and *=7 additional species listed by ENVIS) Impatiens acaulis Arn., Impatiens clavicornu Turcz. *, Impatiens cuspidate Wight *, Impatiens debilis Turcz *, Impatiens denisonii Bedd., Impatiens gardneriana Wight *, Impatiens laticornis Fisch., Impatiens lawsonii Hook. f., Impatiens lenta Hook. f. *, Impatiens levingei Gamble ex Hook. f., Impatiens munronii Wight *, Impatiens neo-barnesi Fisch., Impatiens nilagirica Fisch., Impatiens orchioides Bedd., Impatiens rufescens Benth. ex Wight & Arn., Impatiens scapiflora Heyne & Wall., Impatiens tenella Heyne ex Hook.f. and Impatiens trichocarpa Hook. f. * .
- Chhabra, Tarun (2-6-2000). "Rare balsams in the hills". The Hindu - Features. Chennai: Kasturi & Sons Ltd. Retrieved 22 March 2010. Check date values in:
- Chhabra, Tarun (2006-12-30). "Balmy balsams - The endangered Impatiens, endemic to the upper Nilgiris, offers an excellent illustration of phytogeography." (PDF). The Hindi: Frontline: Nature. Chinnai: Kasturi & Sons Ltd. pp. 69 Volume 23 – Issue 26. Retrieved 21 March 2010.
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- Chhabra, Tarun (2004). Journal of the Bombay Natural History Society. Bombay Natural History Society. 101: 58 https://books.google.com/books?id=JtfaAAAAMAAJ&q=%22Impatiens+denisonii%22&dq=%22Impatiens+denisonii%22&ei=HIumS8biKYyQkATJmd3kBw&client=safari&cd=3. Missing or empty