Verbascum, Linnaeus (1753: 177), Linnaeus, 1753

Sotoodeh, Arash, Attar, Farideh, Laitung, Beryl & Civeyrel, Laure, 2022, Verbascum birjandense and V. urumiense (Scrophulariaceae), two new endemic species for Flora of Iran, Phytotaxa 538 (1), pp. 35-44 : 42

Diagnostic key including morphological similar species

1. Basal leaves sessile......................................................................................................................................................... V. urumiense

1. Basal leaves petiolate .........................................................................................................................................................................2

2. Petiole winged ....................................................................................................................................................................................3

2. Petiole unwinged ................................................................................................................................................................................4

3. Stem angular. Calyx 3–6 mm long. Pedicel 2 times longer than the calyx ..................................................................... V. speciosum

3. Stem rounded, striated or a little angular. Calyx 6–10 mm long. Pedicel a little longer than the calyx ....................... V. songaricum

4. Calyx 4–6 mm long, filament hairs orange ..................................................................................................................... V. erianthum

4. Calyx 2–4 mm long, filament hairs whitish-yellow ...........................................................................................................................5

5. Calyx 3–4 mm long; pedicel 5–7 mm (a little longer than the calyx).......................................................................... V. birjandense

5. Calyx 2–3(–4) mm long; pedicel much longer than the calyx .............................................................................. V. cheiranthifolium