Bupleurum pauciradiatum Fenzl ex Boissier (1872: 848)

Stoyanov, Stoyan, 2018, Taxonomic redefinition of Bupleurum pauciradiatum and B. wolffianum (Apiaceae), Phytotaxa 365 (2), pp. 130-144 : 140-141

Bupleurum pauciradiatum Fenzl ex Boissier (1872: 848) ≡ Bupleurum asperuloides var. laxum Fenzl in Tchihatcheff

(1860: 418) ≡ Bupleurum pauciradiatum var. kotschyanum Koso-Poljansky (1915: 271) , nom. inval. (Art. 26.1)

( Turland et al. 2018)

Type :— TURKEY. Iter Cilicicum in Tauri alpes “Bulgar Dagh”, supra Gülek, 30 June 1853, Th. Kotschy 78 (holotype W 0075794 , photo!, Virtual Herbaria JACQ; isotype LE 00015709 , photo!) .

Annual, 20–80(–100) cm, with a conspicuous main stem and ± virgate branches in the middle and the upper part. Stem ± loose at the top, 4-angular in the upper part, cylindrical below, finely striate, smooth. Branches not spreading or with short secondary branches appressed to the main branches, slender, the shorter patent, loosely at apex, the longest up to 15 cm, arcuate, loosely from the middle, sometimes from the base. Leaves 20–80 × 2–6 mm, narrowly lanceolate, acuminate, with 3–7 veins visible beneath, withered after anthesis, with amplexicaul base, margins scabrous. Umbels 2(–3)-rayed, rays 2–13 mm, erect, unequal, non-divergent or slightly opened, lateral umbels 1(–2)-rayed, short-pedunculate, often with 1-flowered umbellules. Bracts (2–)3, 2–4(–5) × 0.5–0.8 mm, narrowly lanceolate, acuminate, carinate, 3-veined, finely serrulate on margins and veins. Bracteoles (4–)5, 2–3(–4) × 0.5–0.7 mm, linear-subulate, acuminate, carinate, with 3 inconspicuous veins and narrow scarious margins, serrulate on margins and veins, in flowers erect, in fruits ± patent, exceeded flowers, a little shorter than fruits. Umbellules 1–5-flowered, pedicels 0.3– 0.8(–1) mm, unequal. Petals pale yellowish to reddish-yellow, turning brownish-red when dried, limb 0.3–0.4 mm wide, suborbicular, slightly dentate on margins, inflexed lobe two times narrower than limb, apically slightly bifid, reaches almost the base of limb, petal bend and part of inflexed lobe distinctly highly papillose. Anthers 0.2–0.3 mm, filaments 0.4–0.5 mm. Stylopodium 0.2–0.4 mm broad, quite narrower than fruits, styles 0.1–0.15 mm, shorter than stylopodium radius. Mericarps 1.8–2.3 × 0.8–1.0 mm, rounded in transect, unripe smooth, pale green, ripe finely rugulose, light brown, ribs inconspicuous. Vittae small, vallecular 2–3, commissural 4–6.

Distribution: — Bupleurum pauciradiatum has a disjunct Balkan-Anatolian distribution. It occurs locally in Turkey (South Anatolia) ( Snogerup 1972) and Bulgaria (North Black Sea coast, Dobrogea part) ( Fig. 8 ).

Historically, the oldest records of B. pauciradiatum in East Europe (Kamenets-Podolsky, Mohilev, Nikita) came from early authors reviewed by Ledebour (1844), who treated similar plants under B. junceum Linnaeus (1762: 343) . Koso-Poljansky (1915) considered the specimen from Nikita (LE 01043507) as possibly referable to B. pauciradiatum var. leptocladum . He expressed doubts that the distribution of B. pauciradiatum can reach so far north up to Kamenets-Podolsky ( Ukraine) and Mohilev (Belorussia), and rejected these records. He accepted the locality at Nikita (Crimea) but commented that this occurrence deserved attention and revision. Linczevski (1950) also accepted the Crimean record. The latest manuals and checklists of vascular plants of Ukraine and the Crimea still listed B. pauciradiatum as occurring in this territory. Chernova (1972) and Kotov (1987) stated that the species is present in a single locality near Nikita, in the south Crimea, probably following the early report of Koso-Poljansky (1915). The latest European checklist online ( Hand 2011) and the most recent Crimean checklist ( Yena 2012) also accepted this occurrence. In Herbaria LE, MW and PRC we discovered several specimens from the Crimea, which were treated as B. pauciradiatum , but they turned out to be misidentified and belonging to B. asperuloides (see Additional specimens examined).

One specimen labelled as originated from Nikita, the Crimea (LE 01043507) is controversial. Koso-Poljansky noted on the herbarium sheet: “ B. leptocladum , adhuc solummodo e Transcaucasia nota ”, in English “ B. leptocladum , so far known only from Transcaucasia”. Subsequently, Linczevski (1950) revised it as B. pauciradiatum . This specimen actually belongs to B. wolffianum (according to this study). The occurrence of B. wolffianum in Crimea seems to be too unlikely and therefore this specimen is not accepted and the record is not marked on our distribution map ( Fig. 8 ). It can be assumed that this specimen originated from Transcaucasia, where B. wolffianum (incl. B. leptocladum ) is certainly distributed, and the labels were mixed in old collections at some point.

Habitats and Populations in Bulgaria: —A population of B. pauciradiatum in Bulgaria is extremely small; it occupies an area of ca. 10 ha and has a very fragmented structure with only 4–5 small patches. It is located about 500 meters northwest of the Bolata Bay (Kavarna district), where the vegetation is presented by dry calcareous grasslands and shrubs. Part of the locality falls into the Kaliakra Reserve and Stepite Protected Site. The entire population is within Natura 2000 Protected Zone “Kaliakra Complex” (BG0000573). The species grows predominately on the margins of Paliurus spina-christi and Carpinus orientalis shrubs and rarely in open stony grasslands.

Bupleurum pauciradiatum takes part in the habitat type 62C0 “Ponto-Sarmatic steppes”, one of the rarest and most vulnerable European habitats of Directive 92/43/EEC (1992). Major threats to it are recreation and construction of wind power stations.

Figures

FIGURE 8. Distribution of Bupleurum pauciradiatum (solid circles) and Bupleurum wolffianum (solid triangles).