Polygonum anatolicum M.Keskin & Eker, 2025

Eker, İsmail & Keskin, Mustafa, 2025, Polygonum anatolicum (Polygonaceae): a new unique species from Türkiye, Phytotaxa 696 (2), pp. 192-200 : 193-197

Polygonum anatolicum M.Keskin & Eker , sp. nov. ( Figs. 1–4 ).

Type:— TÜRKİYE. Hatay: Antakya, Amanos Mountain, Kızıldağ, near lower Zorkun plateau, serpentine gravel, 1353 m a.s.l., 08 July 2023, Eker 13406a (holotype NGBB!, isotypes at AIBU!, ISTE!).

Diagnosis: —Annual herbs with filiform stem. Leaves of two different types. Basal leaves petiolate and rapidly deciduous. Ocrea 2–4 mm. Inflorescence 1–2-flowered. Flowers tiny (1.2–1.5 mm). The fruiting pedicel elongates but is shorter than the tepal. The fruiting tepal elongates, and the outer lobes are slightly hooked at the apex.

Description: —Annual. Stem 15–25 cm, filiform, slightly 5–7 ribbed; almost prostrate or only ascending at top. Nodes longer than leaves. Leaves 1.3–2.5 mm, stalked at base, elliptic-lanceolate, tapering to a point, 8–12 × 3.0– 3.5 mm, with thickened margins and purplish; falling quickly. Bracts are narrowly linear to filiform, 3–6 × 0.5–1 mm, tapering, and almost sessile; the underside of the bracts is thick and has raised veins. Ochrea on lower parts of the stem in several parts, each part with several veins; ochrea supporting upper flowers lanceolate, entire and almost veinless, 2–4.5 mm, none of the ochrea covering the flowers. Inflorescence lax, widely spaced, 1–2(–3) flowered; inflorescence tips fragile than the lower part of the stem and usually zig-zag. Flowering pedicels shorter than flowers, up to 1.0 mm, usually purplish. Flowers white to light pink when young, 1.2–1.4 mm; lobes are considerably longer than the tube. Stamens 8, at most half the length of the tepals, broad at the base, tapering abruptly near the anthers; anthers minute and spherical. Fruiting tepals slightly enlarged, 1.8–2.2 mm, lobes dark pink, the tip usually closed, completely covering the achene, or only the tips of the achene visible, with few veins, or almost veinless but rough; outer tepal broader than the inner, and slightly hooked at the tip, at the apex of the achene the tips touching each other slightly; tube very short. The longest pedicel is purplish, short, and somewhat thickened at 1.6–2.0 mm, shorter than tepals or slightly equal. Achenes almost as long as tepals or slightly longer, 1.8–2.2 mm, slightly inflated and pyramidal, margins glossy, pale, surface dark brown, smooth. Stigma 3, briefly separated, minute.

Etymology: —The specific epithet is derived from ‘Anatolia’. Polygonum is called “ Madımak ” in Turkish. The authors propose “ Anadolu Madımağı ” as a new Turkish scientific name for P. anatolicum according to the guidelines of Menemen et al. (2016).

Distribution, habitat and conservation status: —This species is known only from locus classicus. Polygonum anatolicum grows on serpentine gravel in pine forest clearings at 1300–1350 m a.s.l. in the Kızıldağ region, located in the southernmost part of the Amanos Mountains in Hatay Province. This region is characterized by serpentine bedrock and hosts numerous recently discovered local endemic plant species, e.g. Leopoldia babachii ( Eker & Koyuncu 2008: 49) Eker (2022: 89) , Allium arsuzense (2011: 392), Muscari inundatum Yıldırım & Eker (2021: 182) , Gladiolus oreophilus Eker & Sağıroğlu (2024: 112) .

In the type locality, we found fewer than 500 mature individuals growing in an area smaller than 1 km 2. Although it is likely to occur in similar habitats nearby, its natural habitat is under considerable grazing pressure by cattle. An additional threat is the presence of a mining quarry in the immediate vicinity of the type locality. Thus, based on IUCN criteria, we assess the species as Critically Endangered (CR) (Criterion B2ab[ii iii, v]) due to its limited distribution and the predicted decline in AOO (Area of Occupancy), habitat quality and number of mature individuals ( IUCN 2024).

Phenology:—Flowering and fruiting in late June and early July.

Notes: —This species has unique characteristics in terms of its structure and its distinct characters. It resembles Polygonum pulchellum Loiseleur (1827: 411) and P. arenarium Waldstein & Kitaibel (1801: 69) , although no exact close species exists ( Fig. 4 ; Table 1). The flowers enter the fruiting period very quickly and can easily fall off. They are short-lived plants native to alpine areas. For this reason, they enter the seeding period quickly and dry up quickly. Flowers are small (1.2–1.4 mm) in the early stage and usually closed at the tips. After pollination, the tepals enlarge and elongate (1.8–2.2 mm), and the surface is usually few-veined.

Figures

FIGURE 1.Polygonum anatolicum: 1.Habitus,2. Numerous intertwined branchlets,3. Close-upof some branching,4.Single inflorescence branch, 5. Base part of the branching, 6. The end part of the inflorescence.

FIGURE 2. Polygonum anatolicum: 1. One of the isotype specimens, 2. Holotype.

FIGURE 3. Polygonum anatolicum: 1. Basal leaves, 2. A single flower, 3. End part of the inflorescence, 4. Ochrea, 5. Inflorescence with young flowers, 6. A single flower, 7. 2-flowered inflorescence, 8. Achene.

FIGURE 4. Distribution map of the Polygonum arenarium, P. pulchellum and P. anatolicum in Türkiye.