This taxonomic monograph on Impatiens L. (Balsaminaceae) of Western Ghats, Peninsular India is a comprehensive treatment of a most difficult genus to classify. This book is the outcome of author's long standing scientific enquiry on the genus for over 35 years. The present book provides a taxonomic treatment of 106 species and 13 infra-specific taxa including 12 additional new species and 6 new varieties from Western Ghats. The elaborate key provided under each section is valuable to all other workers on the genus and will be basis for any other attempts at revision by future authors.
Taxonomic Monograph on Impatiens L. (Balsaminaceae) of Western Ghats, South India also provides useful information on pollen and seed morphological characters, chromosome numbers, embryo sac type and special anatomical characters, if any, which are shown to be reliable tool for correct identification of species in Impatiens. This kind of taxonomic treatment based on both macro- and micro-morphological characters was very much required in this genus which the author has successfully fulfilled. Taxonomic Monograph on Impatiens L. (Balsaminaceae) of Western Ghats, South India contains over 170 colour plates, each plate is dedicated to one species comprising both macro- and micro-morphological characters such as habit, dissected flower parts, fruits, seeds, seed hair morphology, pollen morphology, chromosome numbers and in some cases anatomical and embryo sac types. The chromosome numbers have been reported for 76 species, including satellite taxa of which 37 are fresh counts and chromosome numbers of 25 species are first reports. Nearly 95 species have been palynologically analysed, out of which pollen morphology of 88 species is done exclusively by the author including 21 first reports. Very interesting seed hair morphological characters which have great taxonomic value in classifying Impatiens have been reported for the first time in most of the brown seeded species in the Sections, "Scapigerae", "Microsepalae", "Tomentosae", "Sub-umbellatae" and "Racemosae". A taxonomic note under each species makes an interesting reading on its inter-relationships.
The Western Ghats has long been recognized as the most astounding natural biodiversity hot spot with a highly varied and archaic flora. The author has categorized Impatiens species in Western Ghats for their Threat Status as per IUCN Red List Categories and Criteria. Out of 106 species of Impatiens in Western Ghats, 103 species are endemic to peninsular India, about 37 species (including varieties) fall under the category of Critically Endangered, about 36 species under the category of Endangered and 17 species under the Vulnerable status. Urgent measures are suggested to protect their habitats in Western Ghats.
"The members of the genus Impatiens (Balsaminaceae) are popularly called balsams or jewel weeds. They are also referred to as 'orchid flowers' as their flowers resemble those of orchids. Several species and their hybrids are grown as prized ornamentals and are in great demand throughout the world because of their vivid colors. Taxonomically, the genus encompasses very difficult groups of plants to classify. After his monumental publication The Flora of British India, Sir J.D. Hooker returned to work on Impatiens because he found tremendous diversity in this genus. The work classified approximately one hundred and twenty-three species of Impatiens. However, the author was unsatisfied with his treatment and left a number of open ends for which he could not come to any conclusion.
This taxonomic monograph on Impatiens of Western Ghats provides a comprehensive treatment of 106 species and 13 varieties occurring in the richly biodiverse Western Ghats region. Fifteen new species and six new varieties described by the author himself are included. Taxonomic key for identification is provided to seven sections (formed by Hooker & Thomson 1860) with separate identification keys for species under each section. The author has resurrected I. bababudenensis Hook.f. which was synonymised under I. latifolia by J.S. Gamble. This seems quite logical as the former has n = 6 and the latter has n = 3 chromosome numbers, apart from other morphological differences between the two. Similarly, I. fasciculata (Lam.) has been resurrected as an independent species, and I. chinensis var. brevicornis Barnes has been elevated to specific level.
The most useful information provided by the author is the micro-morphological characters. These include various kinds of banding pattern of testa indumenta in brown-seeded species, pollen morphological characters, chromosome numbers for a majority of species, and, in a few cases, embryo sac type and anatomical characters. A consolidated summary on the chromosome numbers and pollen morphological characters reported by the author as well as other authors is also provided. The plate(s) provided for each of the species
depicts photos of both morphological and micro-morphological characters which readily help one to immediately capture the striking characteristics of the species. The display of dissected floral parts, provided for most of the species, is another important aspect which was very much required for this genus. A case study on autecology of Impatiens acaulis – I. scapiflora complex has been well presented, clearly showing how the plant populations vary greatly from population to population, especially with regard to leaf morphology, flower color, spur length, and wing petals. The author rightly recognizes that stable qualitative traits should only be considered while describing new species.
There is handy information on the range of distribution of each species in the Western Ghats as well as the names of species collected from each of the hill ranges in the region. The author has ably attempted to discuss endemism and affinities, and also origin and evolution of Impatiens of Western Ghats. he believes that the occurrence of lower chromosome numbers of 2n = 6 or n = 3 and larger chromosomes as in the case of I. leschenaultii and I. latifolia occurring in the Nilgiris Mountains and the second lowest chromosome number of 2n = 12 or n = 6 as in the case of I. talbotii, I. pulcherrima, and I. bababudenensis in the northern part of Western Ghats, is clear proof of the primitiveness of Western Ghats species. The author has tried to correlate the type of seed: horny seed and brown seeded seeds with testa indumenta, with endemicity and distribution of Impatiens species in Western Ghats. however, he finds no impact as the extent of endemism between these two categories of species is more or less the same.
Finally, the author has categorized the species of Impatiens reported in Western Ghats according to their threat status. he believes that 7 species are possibly extinct, 40 species fall under the category of critically endangered, 33 under the category of endangered, and 16 are under vulnerable status. These conclusions certainly warrant immediately undertaking stringent measures to protect natural balsam growing habitats. It is also essential to undertake species rehabilitation programs to prevent extinction of endangered species. Another important contribution in this work, apart from the other original material, is the simple low cost technique of 'drip and splash method' which the author has developed to cultivate wild balsams in the greenhouse. This will definitely help to grow practically all balsams with ease for either research or ex-situ conservation.
This work deviates in the presentation of text and illustrations when compared to conventional taxonomic monographs; perhaps the author intentionally structured his work this way in order to break the monotony and make it user friendly. It would have been better if the author had followed the latest and standard nomenclatural norms and carried out better editing of the text before sending the manuscript to press, since lapses are found sporadically in the book. However, there is ample scope to improve the running text as well as to reduce the size of the book by printing plates back to back in the next edition.
Nevertheless, the author has done a commendable job and has produced an excellent piece of work on Impatiens of Western Ghats. I am strongly of the opinion that this type of monograph is needed for all the genera. Indeed, the author has set a model for future taxonomists who would like to take up monographic work on various groups of plants. I am sure it will greatly assist in correct identification as well as emphasizing the importance of using various other micro-morphological characters as supplementary traits in future monographic works. Though the book is priced on a no loss no profit basis, still the price is prohibitive and many individuals could not afford to own this book. however, it will be a good reference book in institutions engaged particularly in taxonomic research. On the whole, no monetary value can compensate for the amount of work and passion that has gone into this valuable monograph."
– S.N. Yoganarasimhan, Ph.D., FBS, FIAAT, Retired Head, Medicinal Plants Division, Regional Research Centre (Ay), Govt. of India, Bangalore. Presently Visiting Professor & Research Co-coordinator, Dept. of Pharmacognosy, M.S. Ramaiah College of Pharmacy, Bangalore 560058, India
Journal of the Botanical Research Institute of Texas 6(1): 315-316, 2012