Reseda balansae Müll. Arg. (1857: 119)

Çilden, Emre, Yildirimli, Şinasi, Zare, Golshan & Martín-Bravo, Santiago, 2018, Rediscovery of the restricted endemic Reseda balansae (Resedaceae) in Turkey, Phytotaxa 362 (1), pp. 87-96 : 90-94

Reseda balansae Müll. Arg. (1857: 119)

Type:— TURKEY. Pl. d’Orient, Gorge du Guzel-Déré, en amont de Sédichig, à 3 lieues au NO. de Mersina, Fl. 20 mai– Fr. 7 juin, 1855, B. Balansa 768 (‘754’). [ C5 İçel: Gorge of Güzeldere ( Efrenk ) up-river from Sedichig ] (Lectotype, designated here: G-00150517!; isolectotypes: BM!, C, DS!, E!, G!, GOET!, JE!, K!, MPU!, OXF!, P!, TL, US!, W!, WAG!, WU!) .

Indicatio locotypica:—“ Habitat in faucibus regiones calidioris secus rivulum Guzel-Déré circa Mersina Asiae minores ”. [ Turkey, Mersin]

Etimology:—Müller Argoviensis dedicated this species to the collector of the type material, B. Balansa (1825–1891).

Iconography:— Abdallah & de Wit (1978: fig. 30); Fig. 3 .

Annual to perennial, 50–110 cm. Stem branched, erect, glabrous. Leaves 2–15 × 0.5–1.8 cm, basal leaves entire, oblong to obovate-spathulate, cauline leaves entire to trisect, decurrent, glabrous; margins glabrous or scabridulous. Inflorescence a raceme 20–45 cm long, lax. Bracts 1.5–3 × 0.25–0.5 mm, erect, linear, persistent, glabrous. Pedicel 2–5(–6) mm in flower, 5–10 mm in fruit, erect or patent, glabrous. Flowers bisexual, perianth 6(–7) merous. Calyx dialysepalous, sepals 1.5–3.5 × 0.5–1 mm in flower, persistent, not or slightly accrescent, usually reflexed in fruit, 2–5 × 0.5–1 mm in fruit, oblong to oblong-spathulate, margin glabrous or rarely scabridulous. Corolla dialypetalous, heteromorphic, white, light yellow when dry. Petals unguiculate, limb trisect, with lateral lobes wider than central one, deeply laciniate. Superior petals 2–3 mm, multipartite, limb appearing 9–13(–16) laciniate; lateral lobes palmatisect, each with (4–)5–6(–8) linear or linear-spathulate laciniae, central lobe linear-spathulate or spathulate, longer or slightly shorter than lateral ones, appendage c. 1.5 × 1–1.5 mm, rectangular-spheroidal, margin papillate. Lateral and anterior petals smaller and reduced; lateral petals 1.5–2.5 mm, sometimes asymmetric, lacking one of the lateral lobes; anterior petal 1–1.5 mm, usually reduced to the central lobe. Disc 0.5–1 × 1.5–2 mm, margin not curved; papillose-scabrous. Stamens 15–20, deciduous; filament 2–2.5 mm, glabrous, not widened in the upper part; anther 0.5–0.75 mm, oblongelliptic. Ovary obovate-elliptic, with three carpels and styles. Capsule 7–14 × 6.5–10 mm, pendulous when fully ripe, obovoid-cylindric to obovoid-subglobose, glabrous, constricted below the teeth and narrow at base (stipitate), mouth wide, capsule teeth 1–1.5(–2) mm. Seed 2.4–2.6(–2.7) × 1.5–1.7(–1.8) mm, 10–21 per capsule, reniform, greyishbrown when mature, testa undulate-rugose, dull; sinus 0.5 mm wide; with carunculoid tissue ( Fig. 5 ).

Ecology: —Calcareous slopes and cliffs, about 350–700 m above the sea level. The vegetation in the area is a Mediterranean forest dominated by Pinus brutia Tenore (1815 : lxxii), with Cistus salviifolius Linnaeus (1753: 524) , Cistus creticus Linnaeus (1762: 738) , Scrophularia lucidaifolia Uzunh. & E. Doğan in Uzunhisarcıklı et al. (2015: 95), Valerianella coronata ( Linnaeus 1753: 34) Candolle (1815: 241) , among others in Işıktepe, and additionally Aethionema spicatum Post (1885: 62) in Kayrakkeşlik.

Distribution: —Endemic from the Eastern Mediterranean, Southern Turkey (İçel province). Fig. 1 .

Phenology: —April–June.

Taxonomic notes: —The type collection is composed of many duplicates which are widely distributed in many European and American herbaria. Müller Argoviensis (1857) did not explicitly designate holotype when describing the species. Later, Abdallah & de Wit (1978) indicated that the “type” (lectotype) is in G herbarium, but without specifying the herbarium number. Since there are several duplicates of the type material at G, it is necessary to formally designate a lectotype. We followed the criterion by Martín-Bravo (2013; in schedula) to select the specimen G-00150517 from G-BOIS collection as lectotype.

MüllerArgoviensis(1857)based R.balansae on Balansa’s specimen number754.However,this number corresponds to material belonging to genus Aegilops ( Poaceae ). This was probably a misprint that was subsequently corrected by Müller Argoviensis himself (1868), which indicated that Balansa’s number 768 is the one which corresponds to the type material of R. balansae . Later authors agree with this explanation ( Boissier 1867, Coode 1965, Abdallah & de Wit 1978).

Phytogeographic notes: —The area in which R. balansae is found is included in one of the main hotspots of plant biodiversity of the Mediterranean Area (Southern Anatolia and Cyprus; Médail & Quézel 1997, 1999). The Eastern Taurus range has been identified as a putative glacial refuge for Mediterranean plants ( Médail & Diadema 2009), and it has an estimated endemism rate higher than 20% ( Médail & Quézel 1997). It constitutes a barrier that delimitates the Mediterranean phytogeographic region lying between the south of this range and the Mediterranean sea, and separates it from the Central Anatolian plateau (e.g. Bilgin 2011), where a much more continental climate exists. Therefore, we consider that emphasizing conservative efforts in Mersin area would not only help to preserve endemic species as R. balansae , but also to contribute to the conservation of the Eastern Taurus range, a hotspot of plant biodiversity.

Palynology: —Pollen grains in R. balansae are tricolporoidal and isopolar, circular at polar view. Polar axis (P) is 19.00–22.00 μm (20.36 ±0.77 μm). Equatorial axis (E) is 17.00–21.00 μm (19.38 ±0.92 μm). P/E ratio is 1.05 and pollen shape is prolate-spheroidal. Amb diameters are 18.00–21.00 μm (18.98 ±0.87 μm). Apocolpium is (t1) 5.00 μm, while apoporium (t2) 15.00–18.00 μm. Colpi are thin and long, easy to observe; colpi length (Clg) is 17.00–20.00 μm and width (Clt) 3.00 μm. Pori are difficult to observe, so that pori widths cannot be measured. Exine layer is thin, 1.50 μm, sexine 0.75 μm and nexine 0.75 μm. Exine sculpture is microreticulate. Muri thickness is 0.5 μm and lumina width is 0.5 μm. ( Fig. 6–7 ).

Palynological measurements are similar to those found in R. armena , R. coodei , R. minoica and R. anatolica , which also belong to sect. Phyteuma (Çilden et al. unpubl. data). Whereas pollen shape in R. coodei and R. anatolica are prolate-spheroidal as in R. balansae , R. armena and R. minoica pollen grains are subprolate. This palynological result indicates that R. minoica differs from R. balansae in pollen shape, but resembles it in pollen size (especially polar axis). Regarding R. malatyana Yıldırım & Şenol (2014: 1014) , one of the chasmophytic and Turkish endemic Reseda species and also member of sect. Phyteuma , it differs from R. balansae in its pollen shape, since is the only species in Turkey that has oblate-spheroidal pollen type.

Conservation assessment: — Reseda balansae has been previously considered as endangered (“EN”) at the national level, in the Red Data Book of Turkish Plants ( Ekim et al. 2000), although this evaluation did not use the standard criteria and rules established by the IUCN (2012, 2017a), and hence this species should have been considered as “Data Deficient” (“DD”) instead of EN. Furthermore, the species has not been included in the IUCN Red List of threatened species ( IUCN 2017b). The type population was rediscovered in 2014, in Işıktepe (Sedichig) village, near Mersin, after 159 years since its first and only known collection. Only 60 flowering individuals were registered. Unfortunately, in 2015 we found that this population had been largely destroyed due to ongoing road works ( Fig. 4 ), and no individual could be located. The only other known population, collected in 1895 from another village of the same province, Kayrakkeşlik (Kagiraki), was rediscovered in 2015 and to our knowledge is the only extant population of the species. It is probably composed of no more than 20 individuals (E. Çilden & G. Zare pers. obs.). According to IUCN guidelines (2017), since only one population is known, the extent of occurrence (EOO) and area of occupancy (AOO) of the species would be only 4 km 2 (2 × 2 km grid cell; IUCN 2017a). Due to the destruction of the type population, it can be considered that the EOO, AOO, area of the habitat, number of locations and number of mature individuals would be declining. Under IUCN criteria (2012), this data easily allow the classification of the species in the “critically endangered” category using criteria B and D: CR B1ab(i, ii, iii, iv, v)+2ab(i, ii, iii, iv, v); D.

Other examined specimens:— TURKEY. C5 İÇEL: Kagiraki, limestone cliffs. March/ May 1896, W. Siehe 93 (JE s.n., OXF-67542, P-05388840, WU-3125). Işıktepe (Sedichig), from Güzeldere (Efrenk river) bridge to Çukurkeşlik village, calcareous cliffs, 355 m, 36°53’40” N, 34°32’25” E, Pinus brutia openings, 10 April 2014, E. Çilden 1609 & G. Zare (HUB, Herb. Yıldırımlı). Ibidem, 14 May 2014, E. Çilden 1621, B. Özüdoğru & G. Zare (HUB, Herb. Yıldırımlı). Kayrakkeşlik (Kagiraki) village, calcareous cliffs, 650 m., 36 ° 58’31” N, 34 ° 28’14” E, Pinus brutia openings, 30 April 2015, E. Çilden 1702 & G. Zare (HUB, Herb. Yıldırımlı). Ibidem, 28 April 2016, E. Çilden 1724 & G. Zare (HUB).

Figures

FIGURE 1. Distribution map of Reseda balansae in Turkey (●: Işıktepe ■: Kayrakkeşlik).

FIGURE 3. Reseda balansae (Turkey, Içel, Işıktepe; EC 1621). A) Habit; B1) Cauline leaf; B2) Basal leaf; C) Flower; D1) Superior petal; D2) Lateral petal; D3) Anterior petal; E1) Capsule with persistent sepals and bract; E2) Longitudinal section of capsule; F) Seed; G) Stem. (Illustrated by Golshan Zare).

FIGURE 4. Reseda balansae (Turkey, İçel, Işıktepe). a) The type population in 2014; b) the same one in 2015, after destruction due to ongoing road works.

FIGURE 5. SEM micrographs of R. balansae (EÇ 1609) seeds. a) General view; b) Seed surface ornamentation; c) Sinus region.

FIGURE 6. Light microscope microphotographs of R. balansae (EÇ 1609) pollen grains. a) Optical section from equatorial view; b) Colpus view, surface ornamentation; c) Optical section from polar view; d) Apocolpium, surface ornamentation.

FIGURE 7. SEM micrographs of R. balansae (EÇ 1609) pollen grains. a) Equatorial view; b) Pollen surface ornamentation; c) Polar view.