<i>DRACOCEPHALUM OLCHONENSE </i>PESCHKOVA (<i>LAMIACEAE</i>) IN CISBAIKALIA
The ontogenetic features of Dracocephalum olchonense Peschkova were studied in Cisbaikalia. Five ontogenetic states were identified in its development: sprouts, juvenile, immature, virginal, and generative individuals. The individuals of D. olchonense develop within one year and undergo the following phases of morphogenesis: primary shoot - branched primary shoot. The plants die off in the generative state. D. moldavica and D. foetidum individuals develop in the same way. The adult individuals of D. olchonense, D. moldavica and D. foetidum are represented by elongated branched shoots; their development phases in each species proceed individually. In the development of elongated branched shoot of D. moldavica and D. foetidum individuals the following phases were found: rosetted - terminal rosetted and elongated ones. The extended phase in D. moldavica individuals is formed at the beginning of ontogenesis in the juvenile state, and in D. foetidum individuals - in immature state. In D. olchonense individuals resetting stage proceeds to the virginal state; all internodes on a shoot of the virginal plant elongate and it becomes elongated. The terminal-rosetting phase in D. olchonense has not been found. The ratio of lengths of a leaf stem to a blade is also a significant diagnostic character distinguishing D. olchonense from D. moldavica and D. foetidum. In adult D. moldavica individuals a blade is 1.5-2 times longer than a leafstalk; the length of a leafstalk of D. foetidum is equal to or slightly less than the length of a blade; in D. olchnense individuals the length of a leafstalk exceeds or is very seldom equal to the length of a blade.