Tanacetum urmiense Tabad, Maroofi & Rastegar 2022, sp. nov.

Tanacetum urmiense Tabad, Maroofi & Rastegar, sp. nov.

Type:— IRAN. Prov. W Azerbaijan: NW of Urmia, Dalanpar Mountain, Lat 37.177219° N, Lon 44.813346° E, 2980 m, 11 July 2017, M.A. Tabad 13792 (HKS, holotype). Figs 1–2.

Herbs, perennial, woody at base, glabrous or sparsely pubescent. Stems tufted, several, ascending-erect, 5–12 cm tall. Leaves mainly basal, stem leaves few or absent; basal leaves up to 35 mm long, up to 12 mm wide, sparsely pubescent, glabrescent, petiolate; petiole as long as blade; blade ovate-oblong, bipinnatisect, primary segments 3–6 pairs, secondary segments 1–3 pairs, oblong, acute, apex mainly mucronate; stem leaves few, smaller and with few segments. Capitula radiate, heterogamous; involucre hemispherical,10–20 × 20–30 mm; phyllaries in 3 or 4 series; outer phyllaries ovate, as long as inner phyllaries, margin membranous; median phyllaries 3–5 × 2–3 mm, margin broadly membranous, glabrous or sparsely pubescent, dark green with deep brown margins; inner phyllaries obovate, margin ±lacerate. Receptacle convex; marginal flowers about 20, white, 7–12 mm long, 2.5–5 mm wide, apex 3- crenate; disk flowers greenish yellow, lobes brownish, narrowly tubular, ca. 2.5 mm long. Achenes immature, ca. 3 mm long; corona ca. 1.7 mm long, laciniate to base.

Additional specimens examined (paratypes): — IRAN. Prov. W Azerbaijan: NW of Urmia, Dalanpar Mountain, Lat 37.176980° N, Lon 44.813662° E, 2950 m, 28 August 2018, M.A. Tabad 13978 (HKS); Prov. W Azerbaijan: NW of Urmia, Boz-e-Sina Mountain, Lat 37.151344° N, Lon 44.791709° E, 3000 m, 24 September 2021, M.A. Tabad 14433 (HKS).

Distribution and habitat: — Tanacetum urmiense occurs in alpine zones close to the borders of Iraq and Turkey. It grows on humid northern slopes between 2800 and 3100 m a.s.l. Phytogeographically it is an Irano-Turanian element.

Taxonomic notes: — Tanacetum urmiense is closely related to T. hololeucum but differs in the following characteristics: plant height (5–12 cm vs. 10–18 cm); indumentum (glabrous or sparsely pubescent vs. densely appressed tomentose); basal leaves dimensions (35 × 12 mm vs. 15–80 × 10–25 mm); capitula diameter (10–20 × 20–30 mm vs. 8–10 × 6–7), and indumentum of the phyllaries (glabrous or sparsely pubescent vs. sparsely or densely hirsutulose).

Conservation status: — Tanacetum urmiense was collected only on Dalanpar and Boz-e-Sina mountains. Fewer than 200 individuals were on each mountain. The total area of distribution was about 6 km 2. Based on the IUCN criteria and categories, we assess T. urmiense to be Critically Endangered (IUCN 2022).

Phenology: —Flowering July to September, fruiting September to October.

Etymology: —The species epithet was derived from Urmia, a city close to the mountains where Tanacetum urmiense was collected.