[5] It has herbaceous,[7] (or deciduous),[5] falcate (sickle-shaped),[4][6] light green and slightly glaucous leaves.

[6] The stem has 2–3 green, marked with purple, slightly inflated, rounded, spathes (leaves of the flower bud).

[6] The stem (and the branches) hold up to 3 flowers,[6] in early season,[3]: 141  in April,[9] May,[5] or between May and June.

[3]: 141  In the centre, of the falls is a 'beard', or line of white hairs, tipped with yellow.

[6] It has 3.8 cm long perianth tube, the style branch is normally, white with violet crest.

In 2000, 11 iris species were studied and their leaf flavonoid, isoflavonoid and xanthone (chemical) constituents were analysed in order to investigate their phylogeny.

[13] As most irises are diploid, having two sets of chromosomes, this can be used to identify hybrids and classification of groupings.

[15][16] : 275 The Latin specific epithet marsica refers to Monti Marsicani (a mountain range) in Abruzzo, Italy.

[18] It is endemic to Italy,[3]: 141 [10][20] within the regions of Umbria, Marche, Lazio,[8] Molise and Abruzzo.

[23] It is also listed as endemic species of the Apennines with Aquilegia magellensis, Centaurea scannensis, Jonopsidium savianum, Goniolimon italicum, Astragalus aquilanus and Achillea luncana.

[24] It grows on the dry grasslands,[21] mountain pastures,[8] and scrub lands.

[21] Iris marsica has only been recorded from a limited number of locations,[7] about 12 localities have a stable population.

Like many other irises, most parts of the plant are poisonous (rhizome and leaves), and if mistakenly ingested can cause stomach pains and vomiting.