A young White Russian officer, pictured at the onset of the Russian Civil War in late 1917
The white flower he wears not only shows his allegiance but was also meant to symbolize honor and loyalty. Especially in the early parts of the Civil War, the Whites were almost all volunteers driven by ideology, as the leadership was unsure whether to resort to conscription, as many suspected it would be counter productive, not just by further alienating the population, but also opening an easy door for Socialism to infect the ranks.
Because of this, the White Armies often had such a high percentage of men from the officer classes, that even many senior officers had to resort to junior roles, and those with less seniority had no choice but to serve as simple privates. Often they would be formed into a single, elite “officer’s company” where they would serve until losses elsewhere required their reassignment. (Via)