Onosma erzincanica Binzet & Eren, 2018

Binzet, Riza & Eren, Özkan, 2018, Onosma erzincanica (Boraginaceae: Lithospermeae), a new scree species from Turkey, Phytotaxa 356 (2), pp. 117-130 : 119-125

Onosma erzincanica Binzet & Eren sp. nov. ( Figs. 1 , 2 )

Shares the rhizomatous perennial habit, the oblong cauline leaves and patent setose stem with O. obtusifolia ( Fig. 3 ), but differs in golden yellow, shorter (14–17 mm) and clavate corollas (pale yellow, 17–20 mm and subcylindrical in O. obtusifolia ), longer (2–5 mm) pedicels (up to 2 mm in O. obtusifolia ), shorter (ca. 4 mm) filaments (5–6 mm in O. obtusifolia ), acute cauline leaves (obtuse in O. obtusifolia ) and having stems covered not only with 2–5 mm long patent setae (2.5-rarely 3 mm in O. obtusifolia ) but also with short hairs (absent in O. obtusifolia ), and chartaceous to membranous leaves, calyx and bracts when dried (herbaceous in O. obtusifolia when dried).

Type: — TURKEY, B 7 Erzincan: Between Kemah and İliç, 25 km after Kemah, on limestone screes, 39 ° 36 ʹ 44 ʺ N, 38 ° 41 ʹ 15 ʺ E, 1570 m, 02 June 2014, Binzet 201417 (holotype: ANK, isotypes: AYDN, GAZI, Herbarium of Mersin University).

Perennial with long subterranean mostly branched, very rarely unbranched woody and creeping rhizome. Stems solitary to numerous, (20–)25–30(–35) cm long and to 5 mm in diameter, covered at base with scaly remains of the previous years leaves, erect to ascending, longitudinally striate to sulcate, with 2–5 mm rigid patent setose and short hairs, divided above into (2–)3–5(–8) unequal branches. Basal leaves 20–30 × 1–2 mm, linear to, oblanceolate, petiolate, shrivelled at flowering time; cauline leaves 20–60 × 3–8 mm, oblanceolate to oblong lower petiolate, upper sesile and smaller in size, covered with robust patent setae on tubercles above and on midrib beneath and short hairy on both surfaces, becoming chartaceous to membranous when dried. Inflorescence of 1–4 cymes, elongating to 20 cm after flowering. Bracts 10–20 x 3–8 mm, similar to uppermost cauline leaves, oblanceolate to oblong, sessile, acute, with patent robust setae on ±tubercles above and on midrib beneath and short hairy on both surfaces, becoming chartaceous to membranous when dried. Pedicels 2–5 mm. Calyx 12–15 mm in flower, to 22 mm in fruit, lobes linear, linear-lanceolate, densely patent setose and short hairy on outside and ±adpressed setose and sparsely short hairy inside, becoming chartaceous to membranous when dried. Corolla golden yellow, 14–17 mm, clavate, short setulose outside, lobes 5, reflexed, 1 × 2 mm, widely triangular, acute, annulus glabrous. Anthers included or sterile tips exerted, linear, 5.5(–6) mm, sagittate, connate at base. Filaments ca. 4 mm. Style 2–3 mm protruding outside the corolla limb, stigma small, distinctly bilobed. Nutlets 3 × 2.5 mm, shortly beaked, shine cream, cream–brown variagated, ventrally keeled, acute. Pollen grains heteropolar, spheroidal, polar axis to equatorial axis ratio is 1.09.

Additional specimen (paratype): — Type locality, 24 June 2015, Binzet 201507 (Herbarium of Mersin University ; AYDN) .

Etymology: —The epithet indicates the link of the new species with Erzincan, the city of Turkey, where it was first discovered in June 2014.

Distribution and site conditions: — Onosma erzincanica seems to be an extremely rare endemic that is confined to screes between Kemah and İliç districts in Erzincan province. Based on the data currently available, O. erzincanica is hitherto known from the type locality and has a suprisingly narrow elevational range (1560–1575 m). The area where the new species was collected is a part of Munzur Mountains. It lies between the latidutes 380 – 400 and longitude 390 – 400 and a massif long-famed for its rich flora, with a high proportion of endemics ( Yıldırımlı 1995). In particular, the Munzur Mountains harbour a great deal of narrow endemics that are only known from that area. According to the grid system proposed by Davis (1965) the new species, falls specifically within the B7 square. Geologically, the stand where the O. erzincanica occurs can be classified under the Dedek formation consisted of Eocene aged mainly limestone and partly sandstone units ( Özer 1994). The geographical distributions of Onosma erzincanica and O. obtusifolia are mapped in Fig. 4 . According to this map, O. obtusifolia displays a northern distribution within a different mountain chain that clearly lies outside of the Munzur Mountains, whereas Onosma erzincanica seems to be geographically isolated from its relative, being one representative of the Munzur Mountains. Putatively the new species is a Irano-Turanian geoelement and grows preferably in sunny places on limestone screes. It is striking that there is no distinct scree vegetation in the area. We failed to record any characteristic species of scree vegetation. All stands seen are fragmentary communities which can be phytosociologically grouped into the xerophtic Astragalo-Brometea Quézel 1973 class and Astragalo-Brometalia order Quézel 1973 ( Quézel 1973, Kürschner 1986, Parolly 2004). Within the species-poor type locality, only Asperula glomerata (M. Bieb.) Grisebach (1846: 166) subsp. condensata (Ehrend.) Ehrendorfer (1958: 125) was recorded associated with Onosma erzincanica , which is a characteristic species of Astragalo-Brometea 1973 class. In light of the phytosociological evidence the occurence of Onosma erzincanica can be expected out of scree, especially within Astragalo-Brometalia communities. Such communities largely occur on limestone slopes surrounding the type locality of O. erzincanica which are at the same time a major vegetation unit of the Irano-Turanian steppe.

Conservation status: —Unfortunately we have little information about the total number of individuals of Onosma erzincanica in its locality. We could not survey various locations around the type locality or in Munzur Mountains. Based on the data currently available and considering the IUCN Red List Categories and Criteria ( IUCN 2012), O. erzincanica could possibly be assigned to the category “Critically Endangered (CR)”. Specifically, the area of occupancy is estimated to be less than 10 km 2, the species is so far known only from a single location and the number of mature individuals is estimated at fewer than 50. Moreover, the area is under heavy grazing pressure. Nevertheless, further surveys during the flowering season could provide additional information, such as the existence of new localities as well as information on population size, which may change the category and the conservation status of O. erzincanica .

Vernacular name: Onosma is called in Turkish “Emzikotu” or “Emcek”. We propose “Kemah Emceği” as a vernacular name for Onosma erzincanica .

Phenology: —Flowering from May to June and fruiting from late July.

Palynology: —Pollen grains are heteropolar, spheroidal and the rate of polar axis to equatorial axis is 1.09. Exine surface of the grains is insular. The insulae have free scabrae and the scabrae are widely spaced. The average means of the number of scabrae in each insulae range from 5 to 12. The main palynological characters and SEM micrographs of O. erzincanica are presented in Table 2 and Fig. 5 .

Nutlet morphology: —Nutlets 3× 2.5 mm, shortly beaked, shine cream, cream-brown variagated, ventrally keeled, acute. Nutlet surface is rugose-rugulose and characterized by its epidermal cells which has small or fine wrinkles ( Fig. 6 ).

Figures

FIGURE 1. Onosma erzincanica in its type locality, photograph by Rıza Binzet (A—habit, B—flowers).

FIGURE 2. The holotype of Onosma erzincanica, photograph by Rıza Binzet.

FIGURE 3. The holotype of Onosma obtusifolia.

FIGURE 4. Distribution map of O. erzincanica (filled circle) and O. obtusifolia (filled triangle).

FIGURE 5. SEM micrographs of O. erzincanica pollen.

FIGURE 6. SEM micrographs of O. erzincanica nutlets.