Heracleum munzurense A.Duran, Lyskov & Paksoy, 2024

Duran, Ahmet, Lyskov, Dmitry, Samigullin, Tahir & Paksoy, Mehmet Yavuz, 2024, Heracleum munzurense (Apiaceae), a new species from East Anatolia, Turkey and taxonomic position of Tetrataenium lasiopetalum, Phytotaxa 663 (5), pp. 267-282 : 272-278

Heracleum munzurense A.Duran, Lyskov & Paksoy sp. nova ( Figs. 2–5 ).

Type: — TURKEY. B7 Tunceli: Pülümür, Kocatepe village, Yalmanlar vicinity, 39°41′94′′N, 39°69′23′′E, 09 August 2022, 1900 m, slopes, streamside, A.Duran & M.Paksoy 10931 (holotype: HUB, isotypes: ANK, GAZI, MW barcodes MW0595849, MW0595850).

Diagnosis: The new species is similar to H. apiifolium and differs in stem sparsely pubescent throughout and retrorsely puberulent below (not glabrous below, sparsely pubescent above); lower leaves unipinnate to pinnatisect (not 1–2- pinnate to biternate); rays 3–7, subequal or equal, 3.5–9 cm long, pubescent (not 4–12, unequal, 1.5–5 cm long, sparsely to densely glandular-pilose); pedicels pubescent (not sparsely to densely glandular-pilose); petals white or pinkish, regular or slightly radiant, puberulous outside (not white, strongly radiant, glabrous outside); outer petals 2.5–3 mm long (not 8–12 mm long); fruits broadly elliptic to oblong, 9–10 × 7–9 mm, antrorsely scabrid-setulose (not broadly elliptic to suborbicular, 4–6 × 3.5–5 mm, glabrous to puberulent); commissural vittae c. 4/5 as long as mericarp, septate (not 2/7–3/7 as long as mericarp, without septa).

The new species is also closely related to H. pastinaca . It mainly differs from above mentioned taxon in stems 45–70 cm tall (not 3–14 cm), stem ±erect, sparsely pubescent throughout and retrorsely puberulent below, 3–4 mm diameter at base (not procumbent or ascending, glabrous, 0.5–1.2 mm diameter at base), lamina of lower leaves 8–15 × 7–13 cm, ±densely pubescent above and below (not 1.5–3 × 0.5–2 cm, glabrous to sparsely glandular-pilose above and below), rays 3–7, subequal or equal, 3.5–9 cm long, pubescent (not 2–3, unequal, 1–2.5 cm long, glabrous), petals puberulous outside (not glabrous), fruits broadly elliptic to oblong, 9–10 × 7–9 mm, antrorsely scabrid-setulose (not obovate to broadly elliptic, 5–8 × 4.5–6 mm, glabrous); commissural vittae c. 4/5 as long as mericarp, septate (3/7–5/7 as long as mericarp, without septa).

FIGURE 7. Distribution map of Heracleum munzurense (■), H. apiifolium (▲), H. pastinaca (●), and H. lasiopetalum (★).

Description: Perennial, polycarpic, aromatic, hemicryptophytic herbaceous plants, 45–70 cm tall. Rootstock slightly thickened, semi-cylindrical, vertical, 3–7 mm ⌀, without petiolar remains or with rarely remains a few papery old-leaf petioles at base of stem. Stems usually several, rarely solitary, 3–4 mm ⌀ at base, striate-sulcate, terete, ±erect, 2–3-branched, sparsely pubescent throughout, retrorsely puberulent below. Leaves multiple, basal leaves and lower cauline leaves unipinnate to pinnatisect; lamina ovate-triangular, 8–15 × 7–13 cm, ±densely pubescent above and below, ±concolorous; leaflets 2–3-paired, 4–7 × 2–4(–5.5) cm (excl. petiolulate), mostly simple, rarely 1–2-lobed or cleft, often lower pairs distinctly petiolulate, upper pairs sessile, ovate to oblong; terminal leaflet 3-lobed, rarely 3-sect, broadly ovate; margin dentate to serrate; petioles 7–16 cm long, rounded, pubescent, scarcely dilated sheaths. Middle and upper cauline leaves pinnatipartite to trisect, trilobed or at base of lateral branches sheath-like form. Synflorescence composed of compound umbels, lateral branches paniculate. Central umbel bigger than lateral umbels, 7–13(–20) cm ⌀, ±obpyramidal, 3–7-rayed. Rays subequal or equal, rounded, 3.5–9(–12) cm long, pubescent. Bracts absent or rarely 1. Umbellules with 9–19 flowers, 2–4 cm ⌀; pedicels pubescent, 7–17 mm long. Bracteoles 1–3 or absent, linear-lanceolate, shorter than pedicels, 1–3 mm long, caduceus or persistent, pubescent. Flowers bisexual, petals white or pinkish, regular or slightly radiant, puberulous, with narrow tip bent inward; the outer petals 2.5– 3 × 2.5–3 mm, obtriangular, bifid, unequal lobe; the inner petals 1.5–2 × 1–1.5 mm, obovate. Stamens 2–2.2 mm long; anthers sub-globular, c. 0.8 mm, dorsally inserted. Calyx teeth minute, 0.7–1.2 mm long, inconspicuous, oblong to triangular. Ovaries densely scabrous; stylopodium short and ±flat, rim undulate; styles c. 1.2 mm long, slender, recurved; stigma capitate. Fruits broadly elliptic to oblong, strongly compressed dorsally, 9–10 × 7–9 mm, antrorsely scabrid-setulose; dorsal vittae 1 per vallecula, equal, septate, filiform, nearly extending to base of fruit; commissural vittae 2, septate filiform, about 4/5 as long as mericarp.

Etymology:—The specific epithet refers to the type locality of the new species—the Munzur Mountains. The Turkish name of the new species was suggested as “munzur öğreği” ( Menemen et al. 2016).

Phenology:— Flowering in July and August; fruiting in August.

Distribution and ecology: —The new species is a narrow endemic to the Pülümür Valley (Tunceli province) of the Munzur Mountains, East Anatolia. The Munzur Mountains are a botanically important area located between the provinces of Erzincan and Tunceli ( Yıldırımlı 1995). This territory is located in the Irano-Turanian phytogeographical region (Fig. 7). The range of the Munzur mountains is one of the centers of plant endemism in Turkey and is located on the Anatolian diagonal ( Ekim et al. 2000). Several new species have been described from this region, including Tanacetum munzurdaghensis Yıldırımlı (1989: 39) , Cerasus erzincanica Yıldırımlı (1993: 115) , Pimpinella tunceliana Yıldırımlı (2010: 10) , Smyrniopsis munzurdaghensis Yıldırımlı (2010: 13) , Campanula ovacikensis Yıldırımlı (2010: 57) , Allium erzincanicum Özhatay & Kandemir (2014: 51) , Prangos munzurensis A.Duran, Lyskov & Paksoy in Lyskov et al. (2022: 66), Pedicularis munzurdaghensis Armağan (2018: 125) . The area is characterized by a wide range of landforms such as plateau and hills in an elevation ranging from 1800 m to 2450 m above sea level. The major vegetation forms in the area are steppe, Quercus forest, mountain rocks, and wetland types. Heracleum munzurense grows on damp places and stony slopes.

International Union for Conservation of Nature (IUCN) red list category: — Heracleum munzurense is known only from the single type locality, its area of occupancy is smaller than 5 km 2. Continuing decline is projected in the light of possible reduction of area occupancy and number of mature individuals due to the area of occupancy has been subjected to systematic anthropogenic activities such as transhumance, construction of new roadways and settlements, and overgrazing pressure (Criteria B1a,b, B2a,b). According to these criteria the species has to be considered Critically Endangered (CR). The population of the new species is very limited, and adverse effects in area of occupancy are leading to the reduction in the number of plants. The current estimated number of flowering individuals in population is less than 110 (Criteria C2a and D). According to these criteria the species has to be considered Endangered (EN). Because of all these factors the species should be considered Critically Endangered (CR) according to the IUCN Red List Criteria for Critically Endangered B1a, b, B2a, b ( IUCN 2012, 2024).

Figures

FIGURE 2. Representative specimen of Heracleum munzurense (holotype).

FIGURE 3. Heracleum munzurense: A—habitus, B—basal and lower cauline leaves, C—sheath-like upper cauline leaves, D—ebracteate umbel, E—petals.

FIGURE 4. Heracleum munzurense: A—upper surface of the basal leaf, B—lower surface of the basal leaf, C—basal leaf (lobed leaflet), D—middle cauline leaves, E—dorsal surface of the fruit, F—septation of vittae, G—stylopodium, H—cross-section of mericarp (a— lateral rib, b—dorsal rib, c—dorsal vittae, d—commissural vittae).

FIGURE 5. The flowers and fruits of Heracleum munzurense, H. apiifolium and H. pastinaca species. H. munzurense: A—petals (white or pinkish), B—hairy fruits and styles, C—dorsal surface of the fruit, D—commissural surface of the fruit. H. apiifolium: E—petals (white), F—hairy fruits and styles, G—dorsal surface of the fruit, H—commissural surface of the fruit. H. pastinaca: I—petals (white or pale purplish), J—glabrous fruits and styles, K—dorsal surface of the fruit, L—commissural surface of the fruit.