SCIENTIFIC CORRESPONDENCE from the three-dimensional point of field) is determined by the relation be- 6. Egghe, L., ISSI Newsl., 2006, 2, 8–9. view. In Table 1, we re-interpret the tween the units in which they are meas- 7. Egghe, L., Scientometrics, 2006, 69(1), original table 3 of Prathap19 now intro- ured. 131–152. ducing the Euclidean index into the We show the importance of dimen- 8. Prathap, G., Scientometrics, 2011, 87, analysis. We see little correlation be- sional analysis and dimensional homoge- 515–524. 9. Prathap, G., Scientometrics, 2011, 88, tween the primary dimensions P, i and , neity in bibliometric analysis. It is seen 555–562. showing that they are indeed orthogonal that while most h-type indices have the 10. Prathap, G., J. Am. Soc. Inf. Sci. Tech- and therefore independent dimensions. dimensions of [P], the newly introduced nol., 2014, 65(1), 214. Also shown in the table is the z-index de- Euclidean index has the dimensions 11. Prathap, G., J. Am. Soc. Inf. Sci. Tech- fined as (i2P)1/3 which was introduced [P3/2]. It is not enough to have an axio- nol., 2014, 65(2), 426–427. by Prathap11 as an h-type index that is matic basis for designing an indicator; it 12. Katz, J. S., Measurement, 2005, 3(1), three-dimensional in nature. It has the is necessary to examine for dimensional 24–28. dimensions of [P]. homogeneity to ensure that it is com- 13. Pendlebury, D. A. and Adams, J., Scien- To visualize the exponential relation- mensurable with other similar indicators. tometrics, 2012, 92(2), 395–401. ships between these indices the results Each indicator can be used in its own 14. Garfield, E., Science, 1955, 122(3159), 108–111. from Table 1 are plotted on logarithmic right but each will scale differently, e.g. 15. Garfield, E., Can. Med. Assoc. J., 1999, scales in Figure 1. Under consideration while the z-index and h-index scale iden- 161(8), 979–980. are four indices, h, z, iE and C. All four tically as [P], the Euclidean index scales 16. Garfield, E., The agony and the ecstasy: 3/2 2 are indices of scientific performance, as [P ] and C scales as [P ]. The form the history and meaning of the journal combining in different ways the primary of the relation between two variables impact factor. International Congress on terms of size (quantity), impact (quality (since they are related to begin with, i.e. Peer Review and Biomedical Publi- or excellence) and consistency or un- each is a measure of the bibliometric per- cation, 2005; http://garfield.library. evenness. Since we are monitoring the formance of top scientists in a special- upenn.edu/papers/jifchicago2005.pdf performance of leading authors interna- ized field) is determined by the relation 17. Leydesdorff, L. and Bornmann, L., J. tionally in a newly emerging field, we between the units in which they are Am. Soc. Inf. Sci. Technol., 2011, 62, 2133–2146. expect that these will be well correlated measured.

18. Zhang, L., Rousseau, R. and Glänzel, with each other. From Table 1, we see 1. Andersen, J. P., Empirical and W., J. Am. Soc. Inf. Sci. Technol., 2016, that the Pearson’s correlation of 0.94 is theoretical consequences of using the 67(5):1257–1265. highest between iE and C and the lowest Euclidean Index for assessing individual 19. Prathap, G., Scientometrics, 2014, 101, correlation of 0.65 is between iE and h. scholarly impact; 2016 arXiv: 889–898; doi:10.1007/s11192-014-1346-z One can go beyond this simple under- 1612.06079v1 [cs.DL] standing and propose that the slope of 2. Perry, M. and Reny, P. J., Am. Econ. the log–log relation of three indices with Rev., 2016, 106, 2722–2741; doi: Received 19 February 2017; accepted 30 the h-index relates to their presumed di- 10.1257/aer.20140850. March 2017 mensions. We see very clearly that while 3. Leydesdorff, L., J. Am. Soc. Inf. Sci. Technol., 2009, 60, 1327–1336; doi: the z-index and h-index scale identically 10.1002/asi. as [P], the Euclidean index scales as GANGAN PRATHAP 4. Bollen, J., Van de Sompel, H., Hagberg, 3/2 2 [P ] and C scales as [P ]. The form of A. and Chute, R., PLoS ONE, 2009, 4, the relation between two variables (since e6022; doi:10.1371/journal.pone.0006022. A. P. J. Abdul Kalam Technological they are related to begin with, i.e. each is 5. Hirsch, J. E., Proc. Natl. Acad. Sci. USA, University, a measure of the bibliometric perform- 2005, 102(46), 16569–16572; doi:10. Thiruvananthapuram 695 016, India ance of top scientists in a specialized 1073/pnas.0507655102. e-mail: [email protected]

Datura discolor Bernh. (Solanaceae), an overlooked species in India

The genus Datura L. (Solanaceae) is one taxonomic evidences by Geeta and sized from their precursor molecules. D. 3 of the important plant groups known for Gharaibeh . metel, D. stramonium and D. inoxia are traditional and modern medicinal uses as Five species, viz. D. ferox L., D. commonly known in India as ‘Dhotra’4. a source of tropane alkaloids. Worldwide inoxia Mill., D. metel L., D. quercifolia Tropane alkaloids such as atropine and the genus comprises about 14 species Kunth, D. stramonium L. are known scopolamine obtained from Datura are in which are native to America, but vastly from India4,5. These are either cultivated great demand in the European countries. diversified in Mexico1. According to or naturalized in different environmental India is one of the leading exporters of Symon and Haegi2, the Europeans intro- conditions throughout the country. Da- Datura species in international crude duced different species of Datura to tura is one of the major plant groups drug market6,7. Closely related species other parts of the world. One of the old- used in the Indian traditional system of share almost similar chemical compounds est occurrences of Datura is from the medicine, especially Ayurveda. Many often leading to taxonomic ambiguity pre-Columbian period in the old world, important drugs are obtained either affecting the trade of authentic raw as has been proven with historical and directly from Datura species or synthe- materials8,9. Though therapeutic uses,

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Table 1. Comparative morphological account of D. inoxia and D. discolor

Character Datura inoxia Mill. Datura discolor Bernh. Habit Puberulent Glabrous (young parts sparsely pubescent) Leaves Ovate to elliptic; crenate, acute to attenuate at apex, lateral Deltoid to apparently pedate, dentate, attenuate to acuminate veins c. 7, brochidodromous, sparsely pubescent above, at apex, lateral veins c. 4, rectipinnate, glabrous above, puberulent beneath sparsely pubescent beneath Calyx Lobes lanceolate with 2–4 unequal toothed apex, tube terete Lobes ligulate to lanceolate with unequally five-lobed apex, tube angular fluted Corolla Reduplicate, c. 11 cm long, white Reduplicate, c. 16 cm long, white with streaks of lilac to pale purple throat Fruit Globose, densely echinulate, c. 5 cm in diameter, persistent Ovoid, somewhat sparsely aculei-echinate, c. 3.5 cm in calyx margin crisped to undulate diameter persistent calyx margin crisped to lacerate Seed Entire or repend–reniform, testa stramineous, smooth to Sinuate–reniform, testa black, bullate to verrucose, not foveolate, distinctly margined, hilar residue absent margined, hilar residue present

(Figure 1 a, c, e and g). From a critical 6. Iqbal, M., Non-Wood Forest Products, 8, study of the literature, protologue and Food and Agriculture Organization of the herbarium specimens, these specimens United Nations, Rome, 1995, pp. 1–39. were identified as D. discolor Bernh. 7. Rath, B., Globalisation, Global Trend in (Figure 1 b, d, f and h). Additional col- Herbal Market, and the Impact Thereof on Medicinal Plants in Orissa, Vasund- lections of D. discolor from adjoining hara, Orissa, India, 2005, pp. 1–62. localities Ghataprabha and Arabhavi 8. Wah, C. L., Hock, S. C. and Yun, T. K., made in November 2016 confirmed its Pharm. Eng., 2012, 32, 1–16. common occurrence in the eastern parts 9. Maheshwari, N. O., Khan, A. and of Belgaum district, Karnataka. The Chopade, B. A., J. Med. Plants Res., specimens with accession nos 1304, 1315 2013, 7, 2885–2897. and 1316 are deposited in NGPCR. 10. Luna-Cavazos, M., Jiao, M. and Bye, R., The natural distribution of D. discolor Bot. J. Linn. Soc., 2000, 133, 493–507. extends across western North America to 11. Bye, R. and Sosa, V., Syst. Bot., 2013, northern Mexico and the Caribbean 38, 818–829. 12. Ahmad, I., Aqil, F. and Owais, M., Mod- Islands. It is also reported to be commer- ern Phytomedicine. Turning Medicinal cially cultivated for extraction of alka- Plants into Drugs, Wiley-VCH, Wein- 13 loids in Egypt . It has been described by heim, Germany, 2006, pp. 25–53. 14 Bernhardi from India (western region 13. Ratsch, C., The Encyclopedia of Psy- with no precise locality). Interestingly, choactive Plants: Ethnopharmacology apart from the protologue, this species is and its Applications. Park Street Press, not documented in any of the publica- Rochester, UT, USA, 1998, pp. 194–195. tions from India. The present documenta- 14. Bernhardi, J. J., Neues J. Pharm. Aerzte, tion of D. discolor is the first collection 1833, 26, 118–158. after type and extended distributional re- ACKNOWLEDGEMENTS. We thank Mr cord of the species in India. So far this Vijay M. Crishna (Director, Naoroji Godrej Figure 1. Datura inoxia. a, Flowering twig; species was overlooked due its morpho- Centre for Plant Research, Satara) for provid- c, flower; e, fruit; g, seed. Datura discolor. b, logical similarity with D. inoxia. D. dis- ing the necessary facilities and encourage- Flowering twig; d, flower; f, fruit; h, seed. color is naturalized in a stretch of more ment. We also thank Ms Priyanka Giranje, Ms

than 100 km along the roadside; often the Durga Jadhav and Mr K. C. Kishor for help

populations are intermixed with D. inoxia. during field tours and plant collections. phylogenetic relationships and molecular Table 1 presents the distinguishing char- evaluation have been studied in the acters of D. discolor and D. inoxia. Received 2 January 2017; revised accepted 16 10,11 genus Datura , in trade it is reported June 2017 to find admixtures of related and allied 1. Luna-Cavazos, M. and Bye, R., Rev. species affecting the authenticity of Mex. Biodivers., 2011, 82, 977–988. BHAGYASHRI B. KUMBHALKAR* 12 source materials . The present study was 2. Symon, D. and Haegi, L. A. R., In Sola- MAYUR D. NANDIKAR undertaken to provide correct taxonomic naceae III: Taxonomy, Chemistry, Evolu- identity of Datura species and their dis- tion (eds Hawkes, J. G. et al.), Academic Naoroji Godrej Centre for Plant tribution in different parts of India. Press, London, 1991, pp. 197–210. Research, 3. Geeta, R. and Gharaibeh, W., J. Biosci., In July 2016, a collection was made 431, Lawkim Campus, 2007, 32, 1227–1244. along the roadside from Hukkeri to 4. Vartak, V. D., Ayurvidya, 1957, 21, 326– Shindewadi, Shirwal, Gokak in Karnataka, with flowers having 333. Satara 412 801, India prominent pale purple corolla throat 5. Bhandari, M. M. and Mehta, M. R., J. *For correspondence. which is completely absent in D. inoxia Bombay Nat. Hist. Soc., 1977, 76, 550–551. e-mail: [email protected]

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