Thermopsis lanceolata R. Br. is a steppe species with a wide eurasiatic area of distribution. The data on ontogenesis of the endemic subspecies Thermopsis lanceolata ssp. jacutica (Czefr.) Schreter on the northern boundary of its geographical range are brought. In the Republic of Sakha (Yakutia) a reduction of numbers of species population is going on. The study of peculiarities of ontogenesis and morphogenesis of T. lanceolata ssp. jacutica in the midst of introduction in Central Yakutia is being carried out with the aim of conservation of the unique endemic subspecies and restoration of its coenopopulations. T. lanceolata ssp. jacutica is a perennial herbaceous hypogeogenic long-rhizomatous plant, it relates to distinct polycentric biomorph. Ontogenesis of long-rhizomatous plants in culture is complex, and consists of short ontogenesis of seeded individual and incomplete ontogeneses of partial bodies. In the pregenerative period of ontogenesis individuals of seeded origin pass the following ontogenetic states: germinants (p), juvenile (j), immature (im), virginal (v). In virginal state a polycentric system is formed. Its ontogenesis is formed from incomplete ontogeneses of partial sprouts in generative young (g 1) and mean age (g 2) states. Morphogenesis of T. lanceolata ssp. jacutica in the making of long-rhizomatous taproot distinct polycentric system is characterized by the following succession of phases: primary sprout (p-im), primary and partial sprout system (v), partial sprout system (g 1, g 2).