Onosma serpentinica Yıldırım & Binzet, 2024

Binzet, Riza, Özdöl, Tuğkan & Yildirim, Hasan, 2024, Onosma serpentinica (Boraginaceae), a new serpentine endemic species from the South-West Anatolia, Türkiye, Phytotaxa 658 (3), pp. 240-250 : 241-245

Onosma serpentinica Yıldırım & Binzet sp. nov. ( Figs. 1–4 )

Type. TÜRKİYE. Muğla: Göcek, tops of the Göcek tunnel, serpentine rocks, 36 o 45’ N, 28 o 54’ E, 231 m, 1 April 2023, H. Yıldırım, B. Elmas & T. Özdöl 10139 (holotype: EGE 43786! isotypes: EGE 43787!, MERA!, HUB!, NGBB!).

Diagnosis: — Onosma serpentinica is similar to O. argentata . It can be easily distinguished from O. argentata by its numerous stems up to 40 cm (not simple and 20–30 cm); Basal leaves 15–50× 3–10 mm, oblanceolate, adpressed-patent setose with tubercles and very short hairy on upper surface; patent setose ±with tubercles and very short hairy on beneath. Cauline, 10–30× 2–5 mm, lanceolate-oblanceolate, acute, middle and upper cauline shorter and narrower, margins ±revulate, sessile, densely ±patent setose with tubercles and very short hairy on both surfaces (Basal and lower cauline leaves, not 70–90× 3–5.5 mm narrowly linear-lanceolate, middle and upper cauline shorter and broader, adpressed-setose on both surfaces, patent setose on margins), Inflorescence 1–2 terminal, 4–7 flowered (not cymes 1–3 terminal, 17–25 flowered); pedicel – 5 mm in flower, – 8 mm in fruits, (not 3–10 mm); sepals 12–14 mm in flower, to 22 mm in fruits, (not 15–20 mm, scarcely accrescent in fruit); petals whitish to cream-white at first, becoming pink or purple and finally bluish-violet or intense purple, papillate to scabrid-papillate (not whitish to cream, with sparsely hairy on the upper part.); anthers as long as to slightly longer than filaments (not slightly shorter than filaments); Filaments ca. 6–7 mm (not 4 mm); Stylus 25–28 mm (not 18–22 mm); nutlets 4.5–5.5× 3–3.5 mm, (not 4× 3 mm) ( Table 1 ).

Description:— Perennial, rootstock with long slender branches; stem numerous, to 40 cm and to 3 mm diameter, densely whitish short patent hairy and whitish patent rigid-setose, setae with ±tubercles. Basal leaves, 15–50× 3–10 mm, oblanceolate, acute, margins ±revulate, subsessile, adpressed-patent setose with tubercles and very short hairy on upper surface; patent setose ±with tubercles and very short hairy underneath. Cauline leaves 10–30× 2–5 mm, lanceolate-oblanceolate, acute, middle and upper cauline shorter and narrower, margins ±revulate, sessile, densely ±patent setose with tubercles and very short hairy on both surfaces. Inflorescence of 1–2 terminal, 4–7 flowered cymes. Bracts shorter than calyx, linear-lanceolate, lowest resembling upper cauline leaves. Pedicels to 5 mm in flower, to 8 mm in fruits, densely whitish patent setose and short-hairy. Calyx 12–14 mm in flower, to 22 mm in fruits, densely patent setose on both sides and with short hairy especially at the apex of lobes; lobes 5, divided to near base, linear, linear to lanceolate, acute, 1–4 mm wide. Corolla whitish to cream-white at first, becoming pink or purple and finally bluish-violet or intense purple, 20–22 mm, cylindrical-inflated, papillate to scabride-papillate, lobes 5, reflexed, 2 mm wide and 1.5 mm long, widely triangular, acute. Annulus glabrous. Anthers sagittate, included, linear, 8–10 mm long, connate at base, bidentate apical sterile appendage 1.5 mm long. Filaments ca. 6–7 mm, arising from the corolla tube. Style 4–5 mm protruding outside the corolla limb, stigma small, distinctly bilobed. Nutlets 4.5–5.5× 3–3.5 mm, ovoid with minutely beaked, acute, ±ventral keeled, smooth, shiny, pale to brownish.

Additional specimen (paratype):— Türkiye. Muğla: Göcek, tops of the Göcek tunnel, serpantine rocks, 36 o 45’ N, 28 o 53’ E, 283 m, 22 April 2023, H. Yıldırım, V. Demir & T. Özdöl 10185 (EGE!) ; ibid. 36 o 45’ N, 28 o 54’ E, 231 m, 22 April 2023, H. Yıldırım, T. Özdöl & V. Demir 10186 (EGE!) .

Phenology:— Flowering from April to May and fruiting from May to June.

Distribution and habitat:— Endemic to western Anatolia, Türkiye. It belongs to the East Mediterranean floristic region. It is only known from the type locality, the province of Muğla, at the top of Göcek tunnel ( Figs. 1–2 ). It is distributed on serpentine rocky areas in Pinus brutia Ten. forest clearings on elevation between 230– 290 m.

Etymology:— The species epithet is derived from its serpentine habitats, where the new species was distributed. Onosma serpentinica ’s vernacular name in Turkish is “Emzikotu” or “Emcek.” In this context, the Turkish name of this species is proposed as “ Muğla emceği,” according to the guidelines of Menemen et al. (2016).

Conservation: The area of occupancy (AOO) for O. serpentinica was calculated as 0.02 km 2, which is estimated to occur in about 200–250 individuals. It is found in very close two locations. It is near the roadside. The region where the population is located is very prone to forest fires. Recently, forest fires have occurred in many places close to the area. Even though no fire has been detected where the species is distributed, there is a high probability of forest fire in the near future. According to the IUCN criteria (2023), O. serpentinica is evaluated as “Endangered” (EN) D.

Palynology:— Pollen grains are heteropolar, trisyncolporate and prolate P/E (Polar axis/Equatorial axis) ratio 1.36. The exine ornemantation is scabrate. The term scabrate was used for the exine sculpturing elements smaller than 1 μm. The average means of the number of scabrae in 1 μm 2 ranges from 20 to 25. The main palynological characters and SEM micrographs of O. serpentinica are presented in Table 2 and Fig. 3 .

Nutlet morphology:— Nutlets 4.5–5.5× 3–3.5 mm, ovoid with minutely beaked, acute, ±ventral keeled, smooth, shiny, pale to brownish. The Nutlet surface is rugose-rugulose and characterized by its epidermal cells, which have small or fine wrinkles ( Fig. 4 ).

Figures

FIGURE 1. O. serpentinica in its type locality, photograph by Hasan Yıldırım (a-habit; b-flowers; c- and d- upper and lower surfaces of leaves; e-calyx)

FIGURE 2. Distribution map of O. serpentinica (filled star) and O. argentata (filled rectangle)

FIGURE 3. SEM micrographs of O. serpentinica pollen.

FIGURE 4. SEM micrographs of O. serpentinica nutlets