Polygala guilanica Sarvi & Faghir, 2021

Sarvi, Ali, Faghir, Marzieh Beygom & Shavvon, Robabeh Shahi, 2021, Polygala guilanica (Polygalaceae), a new species from Guilan Province, N Iran, Phytotaxa 513 (2), pp. 141-151 : 143-148

Polygala guilanica Sarvi & Faghir , sp. nov. ( Polygala L. subgen. Polygala ) ( Figs. 3–5 ).

Type:— IRAN. Guilan province, Masuleh, Gasht-Roodkhan protected area, Kooh-Roubar , limestones, dry stony mountain slopes, 1791 m, 37º14ʹ28″N, 48º95ʹ61″E, 3 July 2020, A . Sarvi 9001 (holotype GUH!; isotype: YUH!) .

Diagnosis:— Polygala guilanica is similar to P. anatolica Boissier & Heldreich (1853: 57) , but it differs by its prostrate and shorter stem, smaller flowers, smaller leaves, lax inflorescence, ciliated outer sepals and 3-lobed caruncle; it also differs from P. kurdica Townsend (1980: 184) by its anastomosing nerves of inner sepals, united filaments throughout their length, symmetrical capsule wings and its stipitate capsule. Moreover, it differs from P. hohenackeriana Fischer & Meyer in Fischer et al. (1838: 42) by its corolla and inner sepals color, outer sepals shape, inner sepals nerves pattern and seed shape.

Description:— Plant perennial, herbaceous, prostrate, root straight to oblique, thick and woody, branches arising at the base, pubescent, densely leafy, 5–5.5 cm in height; leaves small, 10–13.75 × 3.5–4.6 mm, simple, alternate, sessile, lanceolate, ovate, rhombic, covered with short curved trichomes, with acute to obtuse apices and strigose trichomes on margin; racemes axillary and terminal, lax, 2–2.5 cm; bracts small and deciduous, 1–1.5 mm; outer sepal not gibbous, ciliate, magenta and green-white, the two smaller 4.9–5.1 × 0.7–0.81 mm, obtuse apices, the longer one 5.2–5.35 × 0.8–0.97 mm, magenta to red in color, ciliate at the apex and margins; inner sepals 9.3–10 × 4.2–5 mm, petaloid, elliptic, acute sometimes obtuse, magenta to pink with bright anastomosing nerves; corolla 11.5–12 mm, pink to white, floral appendages white to pale pink, fimbriate; stamens 8 or 6, filaments free and connate up to the middle forming an open glabrous staminal sheath grouped into 1-lobed of 8 or 6 sessile anthers; style filiform, tapering above and below, 4–4.3 mm with an inconspicuous curvature at the base, stigma apical to subapical, with unequal lobes; capsules obcordate, 4–4.5 × 2.3–2.5 mm, with small depression at the apex, glabrous, stipitate, wings very narrow occurring only at upper margins; seed elliptic, 2–2.3 × 0.85–0.95 mm, brownish, with simple hairs, 3-lobed white to creamy caruncles.

Etymology:— Polygala guilanica refers to Guilan province in N Iran.

Phenology: —Flowering in June–July and fruiting in July–August.

Distribution and ecology:— Hyrcanian region boasts substantial plant biodiversity. Considerable moisture from N Atlantic Ocean, Mediterranean Sea and Black Sea to this region has caused a conspicuous area covered with miscellaneous endemics ( Akhani et al. 2010). Polygala guilanica is a tiny prostrate, semi-alpine Hyrcanian element from the type locality in west of Guilan province, N Iran. Growing on limestone, dry stony mountain slopes and dry meadows at 1700-1800 m elev.

Conservation status:— It is clearly prominent that, some Polygala species usually occupy small areas and consequently, they are classified as endangered or rare species ( Dönmez et al. 2015, Jiang et al. 2016, Dönmez & Uðurlu Aydin 2018, Sarvi et al. 2020). In flora of Iran, P. irregularis Boissier (1846: 130) , P. kurdica , P. monspeliaca Linnaeus (1753: 702) and P. mazandarnica represent four species with restricted growing areas ( Chrtek & Krisa 1977, Ghahraman & Attar 1999: 320, Jalilian 2005, Sarvi et al. 2020). Polygala guilanica also occupies restricted areas, currently estimated less than 1000 m ² and it probably should be considered as a rare and endangered species. In similar cases, species are often considered as Endangered or Critically Endangered (e.g. Rebelo et al. 2011, Wagensommer et al. 2014, 2017, Massó et al. 2018), but it is not mandatory, especially if there is no observed decline (e.g. Perrino et al. 2018, Wagensommer et al. 2020). Therefore, the conservation status of Polygala guilanica should be evaluated in future, after collecting more data in field, according to IUCN (2019) categories and criteria.

Additional specimens examined:— Polygala anatolica : IRAN. Guilan, Rostam Abad, Salansar, Kalurz , 36°80’09”N, 50°63’61”E, 30 May 2019, A. Sarvi 8341 ( GUH!); Mazandaran, Ramsar, Dalkhani jungle, Jannat Roodbar road, 36°81’55”N, 50°64’51”E, 10 May 2019, A. Sarvi 8340 ( GUH!). Polygla hohenackerina : IRAN. Tehran, Chitgar , 18 April 1984, A. Ghareman 8136 ( TUH!) ; IRAN. Qazvin, Avaj, Abe garm, Sagharan-e O’lya, 35°70’19”N, 49°33’11”E, 14 April 2019, A. Sarvi 8339 ( GUH!). Polygala kurdica : IRAN. Kermanshah, Sarab-e Kerand , 15 September 1989, Iranshahr & Dezfoolian 33222 ( IRAN!) .

Figures

FIGURE 3. Polygala guilanica (from locus classicus: Kooh-Roubar 3 July 2020. A. Sarvi 9001) in natural habitat (Kooh-Roubar, Guilan province, N Iran). Photos by A. Sarvi.

FIGURE 4. Polygala guilanica (from A. Sarvi 9001).

FIGURE 5. Polygala guilanica (from A. Sarvi 9001). A) leaves; B) short, curved and strigose trichomes at leaves margin; C) short, curved and strigose trichomes on stem; D) lax raceme; E) sepals; F) corolla and wings; G) details of flower, arrow shows basal curvature of style; H) six and eight sessile anthers in two different flowers; I) stipitate capsule; J) pistil; K) seeds; L) 3-lobed caruncle; M) anastomosing nerves of inner sepal.