In this paper a review of the nomenclature, etymology, taxonomy, morphology, histology, life cycle, phenology, reproduction, habitat preference, biotic interactions, biologically active compounds, micropropagation, application possibilities and conservation status of Siberian flag (Iris sibirica L.) can be found. Leaf traits, phenological data, seed-set, thousand-seed weight, germination, growth rate and soil characteristic data are published based on original observations:

• Leaf area is between 25,3 and 52,9 cm², its dry mass is 232 and 272 mg/g, specific leaf area is 14,5 and 15,0 m²/kg; based on measurement of 5–5 leaves of sibirica, collected from Tapolca and Létavértes (Hungary) in May of 2014.
• Based on herbarium dataset, blooming of sibirica begins at the end of April and lasts to early-July, contrary to the literature data (May–June).
• Capsules contain (0–)58–76(–121) fertile seeds. (20–)60–80(–90)% of ovules develops to (seemingly) viable seeds, meanwhile the other ovules remain as aborted ones or develop to infertile seeds (probably because of absence of resources); based on fruits collected from Regéc (Hungary) in 2014 and 2015.
• Thousand-seed weight of sibirica is 8,8298–11,2914 g (based on 3×100–100 seeds collected from Regéc and Tapolca in 2014 and 2015), which is lower value than the literature data.
• In our germination test (50–50 seeds sowed to wet soil, after different treatments) 14% of scarified seeds, 6% of scalded seeds, 4–4% of imbibed and control seeds, 0–0% of cooled and refrigerated seeds are germinated. Scarified seeds germinated in the 8–26^th days, imbibed seeds 15–19^th days, control seeds 16–20^th days, scalded seeds 20–23^th days after sowing. It seems that scarification stimulates, meanwhile temperature-treatments inhibit the germination. Until 18 weeks the seedlings grow to 30 cm (in mean) and develop 5–7 leaves (in mean). After the 14^th week, the first and littlemost lateral leaves are necrosed.
• Analyses of soil samples collected from 17 locations of sibirica in Hungary, suggest that the species prefers highly acidic to slightly alcalic, lime-free to highly calcareous soils with generally high amount of humus and clay, different amount of phosphorus, potassium and nitrogen and low concentration of salt.