Hieracium boratynskii Szelag 2022, sp. nov.

Hieracium boratynskii Szeląg, sp. nov. (Figs. 1−3)

Type: ― POLAND. Sudetes, Karkonosze Mts., Kocioł Łomniczki glacial cirque, rocky and grassy slope with Pinus mugo on granite, 1370 m a.s.l., originally found on July 15, 2017, specimens from plants cultivated from seed in the author’s garden, pressed on June 5, 2021, Z. Szeląg (holotype KRAM; isotypes Herb. Hierac. Z. Szeląg).

Description: —Phyllopodous. Stem 30–40 cm high, pale green, within synflorescence with numerous stellate hairs, very sparse yellowish glandular hairs 0.3–0.5 mm long, without or with very few pale simple hairs up to 1 mm long, in the middle only with sparse stellate hairs, at the base with sparse stellate hairs and few pale simple hairs up to 2 mm long. Rosette leaves 6–12 (up to 20 in cultivation), overwintering, present at anthesis, glaucous, lanceolate or elliptic-lanceolate, subentire or remotely and sharply denticulate to sinuate-dentate, 4–12 cm long and 1–2.5 cm wide, acute at the apex, gradually tapered to a ±winged petiole, covered by numerous pale simple hairs up to 2.5 mm long; on the upper surface glabrous or with sparse stellate hairs; on the lower surfaces with sparse pale simple hairs 1–2 mm long and a few stellate hairs along the midrib; on the margins with numerous stiff pale simple hairs up to 1.5 mm long, mixed with stellate hairs and microglands. Cauline leaves 1–3, rapidly reduced in size upwards; the lower ones up to 9 cm long and 1 cm wide, lanceolate, entire or nearly so, gradually tapered to a ±winged petiole; on the upper surface glabrous or with sparse stellate hairs; on the lower surfaces with sparse stellate hairs; on the margins with scattered stiff pale simple hairs up to 1 mm long, mixed with stellate hairs and few microglands. Upper cauline leaves bract-like, up to 1 cm long. Synflorescence with 6–10(–15) capitula (and usually some capitula aborted). Synflorescence branches 1–2 (the lower ones up to 22 cm long), often in axils of all cauline leaves, with 1–3 capitula, covered by numerous stellate hairs. Acladium up to 4 cm long. Peduncles green, with dense stellate hairs, few to scattered yellowish glandular hairs 0.2–0.4 mm long and very few grey simple hairs up to 2 mm long. Bracteoles 2–4, lanceolate, covered by dense stellate hairs mixed with simple hairs. Involucres subglobose at the base, 11–12 mm long, covered by moderately dense indumentum. Involucral bracts in three rows, 1.0– 1.1 mm wide at the base, lanceolate, acute at the apex; outer bracts blackish green, with dense stellate hairs along the margins, scattered grey dark-based simple hairs 0.8–1.1 mm long, and numerous yellowish glandular hairs 0.3–0.5 mm long (ratio of simple hairs to glandular hairs 2.5: 1); inner bracts green with dark grey midrib and very sparse indumentum. Ligules yellow, glabrous at the apex. Styles yellow. Achenes black, 2.4–2.7 mm long. Pappus pale grey. Pollen in anthers sparse, irregular. Flowering: July.

Affinity: ― Hieracium boratynskii is similar to H. canescens subsp. zobelianum from the Harz Mountains but differs in its (1) glabrous or almost so upper surfaces of leaves, (2) peduncles with dense stellate hairs, and (3) involucres 11–12 mm long with numerous glandular hairs.

Hieracium boratynskii may have originated as a result of hybridization between H. levicaule s. lat., which is widespread in the Karkonosze Mountains, and the narrow-leaved H. schmidtii subsp. jovimontis (Zahn) Greuter (2007: 173). As no diploid populations of these taxa are currently known in the Karkonosze Mountains, such a hybridization, if at all possible, must be extremely rare. Otherwise, H. boratynskii is a relict taxon like many other hybridogenous, apomictic Hieracium species endemic to these mountains.

Distribution and habitat: —Endemic to the Karkonosze Mountains in the Sudetes, known only from the type locality. In 2017, the population of H. boratynskii comprised a few plants including three flowering ones. They were growing in subalpine rocky grasslands amongst Pinus mugo, at 1350–1370 m a.s.l. As H. boratynskii is a very rare and endangered species, its reintroduction is planned using plants cultivated in the garden.

Etymology: ―The new species is named in honour of Prof. Dr. Adam Boratyński, Institute of Dendrology, Polish Academy of Sciences, Kórnik, for his noteworthy contribution to the knowledge of trees and shrubs of the Sudetes (Boratyński 1991).