~ 109 ~ Journal of Medicinal Plants Studies 2019; 7(6): 109-112 ISSN (E): 2320-3862 ISSN (P): 2394-0530 NAAS Rating: 3.53 JMPS 2019; 7(6): 109-112 © 2019 JMPS Received: 25-09-2019 Accepted: 27-10-2019 Mariam Bozhilova Forest Research Institute - Bulgarian Academy of Sciences, 132, “St. Kliment Ohridski” Blvd. 1756 Sofia, Bulgaria Corresponding Author: Mariam Bozhilova Forest Research Institute - Bulgarian Academy of Sciences, 132, “St. Kliment Ohridski” Blvd. 1756 Sofia, Bulgaria Morphometric characteristics of Galium odoratum L. (Scop). from Bulgaria Mariam Bozhilova Abstract The aim of the study is to analyze the morphometric parameters of 10 populations of Galium odoratum from Mala Planina and Ponor Mountains (Bulgaria), in accordance with the specific conditions of their habitat, and to define the similarity between their morphological characteristics by cluster analysis. The majority of the studied morphometric parameters show a medium degree of variation between populations. Cluster analysis showed differences between the individual populations between 0 and 38%. The highest similarity was detected between the populations from habitat M-II-1 CD-2,3. With the soil humidity being the main difference between the habitat types, the analysis shows its strong role in the formation of biomass in Galium odoratum. Keywords: Galium odoratum, morphometric characteristics, variation, similarity Introduction Galium odoratum is a medicinal plant with proven pharmacological properties. In Bulgaria, the species grows in shady, predominantly beech and hornbeam forests, from 0 to 1700 m altitude (Bondev, 1995) [1] . Galium odoratum is subject to a special regime of conservation and use because of the risk of resource depletion. According to the provisions of the Medicinal Plants Act (2000), the special regime is determined annually until February 10 th by an order of the Minister of Environment and Water. Since 2011 in the region, subject of the study, the collection of Galium odoratum for commercial purposes is prohibited. Cultivation of the species will provide the necessary raw material while reducing the negative impact on the natural populations of the species. In order to be effective, cultivation has to be based on a knowledge of the biology and ecology of the species. In Bulgaria, such studies for Galium odoratum are insufficient. Investigation on the morphological variability of Galium odoratum in Southern Belgium (Martin & Bodson, 2010) [4] concluded that most of the morphological parameters (shoot growth, number of leaves in a node, leaf area, etc.) vary significantly in different locations. The morphological characteristics of the species in Bulgaria and their dependence on the environmental conditions are insufficiently studied. The aim of this article is to study the morphometric parameters of Galium odoratum from Mala Planina and Ponor Mountains, in accordance with the specific environmental conditions, and to define the similarity between populations from different localities by cluster analysis. Materials and Methods Subject of the study are 10 populations of Galium odoratum from Mala Planina and Ponor Mountains. Measurement of the studied morphological characteristics was carried out on fresh plants harvested at the end of flowering - beginning of fructification. The following parameters are analyzed: 1) leaf width; 2) leaf length; 3) leaf length/width ratio; 4) number of leaves per node; 5) number of leaves per stem; 6) stem diameter; 7) stem height; 8) inflorescence height; 9) number of flowers per stem. The leaf dimensions were analyzed separately per each node. The accuracy of measurement is 0.1 mm. For the statistical analysis only the dimensions of the first 4 nodes are used, as only part of the stems have more (5-8) nodes. The statistical analyses are performed using Microsoft Excel 2019 and NCSS 2019 software. The degree of variability of the measured characteristics is evaluated by the coefficient of variation (CV%), based on the scale of Mamaev (1968). Cluster analysis is made using the group average (unweighted pair-group) method, based on the Euclidean distances between the samples.