Hieracium vladimirovii Szelag 2018, sp. nov.
Creators: name: Szeląg, Zbigniew
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Asterales
Asteraceae
Hieracium
Hieracium vladimirovii

description: Hieracium vladimirovii Szeląg, sp. nov. (Figs. 3‒4)   
 Type: ― Specimens from plants cultivated in the author’s garden, pressed on June 14, 2017, from the seeds collected in BULGARIA. Kaloferska Planina Mountains, Kamenlivica, ca 2 km SE of Mt. Botev, at 1200 m a.s.l., eroded, siliceous rocks along touristic road from the Panicite village to the chalet Ray, 31 July 2000, Z. Szeląg (holotype SOM 175985; isotypes SOM 175986 & 175987, KRAM, Herb. Hierac. Z. Szeląg).   
 Paratype: ― BULGARIA. Kaloferska Planina Mountains, siliceous screes by a tourist trail from the chalet Pleven to Mt. Botev, at 1800 m a.s.l., 25 July 2001, Z. Szeląg (Herb. Hierac. Z. Szeląg) (Fig. 5).   
 Description: ―Phyllopodous. Stem 25–45 cm high, in the lower third with dense, pale, 4–5 mm long simple hairs; in middle part with scattered to numerous, pale, 3–5 mm long simple hairs and sparse stellate hairs; in upper third and within synflorescence with scattered to numerous, dark-based, 3–4 mm long, simple hairs and numerous stellate hairs. Synflorescence branches (1–)2–5 (the lower ones up to 30 cm long), often in axils of all cauline leaves, with 1–2(–4) capitula, covered by numerous stellate hairs and scattered, dark-based, 3–4 mm long, simple hairs. Acladium ca 2 cm long. Rosette leaves 8–15, up to 15 cm long and up to 2 cm wide, lanceolate to oblanceolate, acute at apex, more or less sinuate, sharply denticulate to dentate, gradually tapered to a long, winged, purplish petiole, covered by dense, pale, 5 mm long simple hairs; on upper surface with sparse, 2–3 mm long, pale, simple hairs; on lower surface with numerous, 2–3 mm long, pale, simple hairs, only on midrib with scattered stellate hairs; on margins occasionally with few microglands. Cauline leaves 2–4, sessile, gradually reduced in size upwards, lanceolate, acute at apex, sharply, remotely denticulate to dentate, on upper surface almost glabrous, on lower surface and on margins with scattered to numerous, 2–3 mm long, pale, simple hairs, only on midrib with scattered stellate hairs, and on margins mixed with sparse microglands. Synflorescence with 5–8(–15), erect capitula (and usually some capitula aborted). Peduncles with scattered to numerous dark-based, 3 mm long, simple hairs, numerous stellate hairs, and scattered, dark, 0.2 mm long glandular hairs. Bracteoles 1–3, green, with numerous, 1–2 mm long, simple, dark-based hairs and mixed stellate hairs. Involucres 11–12 mm long, globose at base, with dense indumentum. Involucral bracts in three rows (outer bracts very short), obtuse at apex, up to 2.2 mm wide at base, dark green to blackish green, with dense, 2–3.5 mm long, pale, dark-based, simple hairs, sparse, 0.2 mm long, dark glandular hairs (ratio of simple hairs to glandular hairs 5:1), and scattered stellate hairs on margin and at base of outer bracts, and a tuft at apex; inner bracts with wide, pale margins and far less dense indumentum. Ligules yellow, glabrous at apex. Styles yellow with dark microtrichomes. Achenes dark brown, 3.9–4.2 mm long. Pappus white. Pollen in anthers numerous, spherical and of varying size. Flowering: July.   
 Affinity: ― Hieracium vladimirovii shows a combination of morphological characters of H. cernuum and H. olympicum, and may have originated as a probable hybrid between these two species. The features referring to H. cernuum are (1) the shape of cauline leaves, (2) wide involucral bracts, and (3) the stem thinner and shorter than in H. olympicum. The relation with H. olympicum can be seen in (1) the branching of the synflorescence (2) the shape of capitula, (3) the dense indumentum of involucral bracts, leaves, stem and peduncles, and (4) the autumn rosette leaves rounded at the apex, shorter and wider than in H. cernuum.   
 Hieracium cernuum is a common species in the subalpine habitats of Mt. Botev, while thermophilous H. olympicum is widely distributed in the forest zone, and I have never found both species growing together. Randomly collected plants of H. olympicum in a population disjoined of ca 1, 5 km SE from the locus classicus of H. vladimirovii were found to be triploid (Chrtek et al. 2007).   
 Distribution and habitats: —Endemic to the Botev massif in the Kaloferska Planina Mountains, known only from two gatherings, but its occurrence in the neighbouring area is expected. It grows on eroded rocks and crevices, in the Fagus sylvatica zone and the subalpine zone. In 2000, the population of Hieracium vladimirovii in the locus classicus comprised ca 20–30 plants, growing on a south-facing slope, on eroded, siliceous rocks. The subalpine population is probably more numerous and dispersed over a larger area, on siliceous screes, but I have not conducted specific searches.   
 Chromosome number and mode of reproduction: —2n = 4x = 36, agamospermous (Musiał & Szeląg 2015: 118, as Hieracium sp. ‘Botev’).   
 Etymology: —The species epithet honours Dr. Vladimir Vladimirov (Владимир Владимиров), Institute of Biodiversity and Ecosystem Research Bulgarian Academy of Sciences, Sofia, an expert in the Bulgarian flora and the genus Hieracium, my trusted friend and companion in field studies over the last twenty years.
description: Published as part of Szeląg, Zbigniew, 2018, Hieracia balcanica XIV. Two new species in Hieracium sect. Cernua (Asteraceae) from Bulgaria, pp. 125-132 in Phytotaxa 348 (2) on pages 128-130, DOI: 10.11646/phytotaxa.348.2.7, http://zenodo.org/record/13708788