Crocus tuna-ekimii Yüzb., 2017

Yüzbaşioğlu, Sirri, 2017, Crocus tuna-ekimii (Iridaceae), a new species from Turkey, Phytotaxa 314 (1), pp. 110-116 : 111-114

Crocus tuna-ekimii Yüzb. sp. nov. ( Fig. 1 )

Crocus tuna-ekimii differs from the closely related C. sozenii by having yellow-orange flowers (vs. violet-blue), chromosome number and karyotype formula 2n = 2x = 12 = 6m + 6sm (vs. 2n = 2x = 8 = 4m + 4 sm).

Type:— TURKEY. Balıkesir, Dursunbey, Durabeyler köyü, Pinus nigra ormanı altı, kayalık arazi, 1000 m, 27 February 2016, S. Yüzbaşıoğlu 4248 & F. Canız (holotype ISTE 112782!, isotypes ISTE!, NGBB!).

Corm ovoid to subglobose, around 1 cm in diameter. Outer tunics coriaceous, inner softer, neck 3–4.5 mm long; coriaceous rings with many conspicuous teeth, teeth 0.5–1.25(–2.2) mm long. Cataphylls 4 or 5, white. Leaves 2–2.11– 3 (n = 46), glaucous, 1.5–4 mm wide with (3–)5–7 ribs in lateral channels depending on leaf width, erect, distinctly Vshaped, sparsely ciliate on edges and keel margins; white stripe prominent, 1/4–1/5 of leaf width; shorter than flowers. Prophyll absent. Bract and bracteole present, membranous, white, bracteole slightly shorter than and hidden within bract. Flowers 1(–2), yellow-orange. Perigone tube (5–)7.5–10.5(–12) cm long, purplish. Perigone segments elliptic to obovate, apex subacute to obtuse, yellow-orange. Outer segments 23–30.5 × 9.5–12 mm, abaxial surface usually striped brownish, stripes covers 1/3–3/4 of segments, not reaching apex of abaxial surface. Inner segments usually slightly shorter and wider than outer segments, 22–29 × 9.6–13.4. Throat yellow-orange, glabrous. Filaments 6.25–9.5 mm long, orange, usually sparsely scabrid throughout. Anthers arrow-shaped, 10.2–14(–18) mm long, yellow, lobes 2.25–3(–4.5) mm. Connective colorless to light yellow; pollen yellow. Style orange, divided into 3 branches, often expanded or fringed at apex, branches 5–10.5 mm long. Style to stamen length ratio 73% shorter, 22% equal, and in 5% slightly longer (n = 38). Capsules at ground level, purple, oblong, 12.25–18.5 × 5.45–7.75 mm. Seeds ellipsoid, 2.1–2.4 × 1.5–1.75 mm, brown with prominent caruncle and poorly developed raphe.

Paratypes:— TURKEY. Balıkesir, Dursunbey, Durabeyler köyü, Pinus nigra ormanı altı, kayalık arazi, 1000 m, 15 March 2004, S. Yüzbaşıoğlu 2433, M. Mustard ( ISTE 112781 !) ; ibidem, 18 May 2016, S. Yüzbaşıoğlu 4258 (capsule & seeds) ( ISTE 112783 !) .

Phenology:— C. tuna-ekimii flowers February to March, while mature fruits are produced in May.

Etymology: —The specific epithet honors Tuna Ekim, a well-known Turkish taxonomist and mentor of the author. The Turkish name of this species is given as “bey çiğdemi”, according to guidelines of Menemen et al. (2013).

Analysis of seed testa surface:—Micro-structures of the seed surface was found a good marker for a systematic grouping of the entire genus by Kerndorff et al. (2015). The new species has tuberculate seed surface with conical papillae and filiform excrescences ( Fig. 2a–c ).

Karyology:— Crocus tuna-ekimii is diploid with 2n = 12 ( Fig. 3a, b ). The karyotype formula is 2n = 2x = 12= 6m + 6sm, and the metaphase chromosome length ranges from 2.26 to 4.21 μm. The chromosome number for C. sozenii is 2n = 8 (bulbs collected from type locality) ( Fig. 3c, d ). The karyotype formula is: 2n = 2x = 8 = 4m + 4sm, and the metaphase chromosome length ranges from 2.95 to 4.38 μm.

Ecology, distribution and proposed conservation status: —The new species grows on marble bedrock (Jura- Cretaceous) under Pinus nigra J.F.Arnold forest at 1000 m elevation ( Fig. 4 ). Although it is found side by side with Crocus flavus subsp. dissectus T.Baytop & B.Mathew at the type locality, the new species usually prefers to be on the bedrock like Galanthus gracilis Čelak. As presently known, C. tuna-ekimii is a narrow endemic and known only from the type locality, in north-western Anatolia. The estimated extent of occurrence was calculated as ca. 0.1 km 2. No deterioration has been detected in the area since 2004, when it was first discovered. However, there are marble quarries in the vicinity. This situation can be regarded as a threat in the future when considering the peculiar habitat of the species.According to available data, the conservation status of C. tuna-ekimii is evaluated as Critically Endangered (CR), [B1ab(i, ii) + 2ab(i, ii)] ( IUCN, 2001).

Taxonomic relationships:—Based on its orange-yellow flowers, annulate corm tunic, and three-branched style, C. tuna-ekimii can be grouped with C. chrysanthus s.l. ( Candan & Özhatay, 2013), C. muglaensis , C. uschakensis , C. henrikii , and C. gembosii . However, C. tuna-ekimii can be easily distinguished from the above close relatives by having fewer (usually 2) and wider (up to 4 mm) dark green (glaucous) leaves, more ribs (up to seven) on both surfaces and abaxially, and by having usually only a single flower per corm. In contrast, the species mentioned above generally have more leaves and flowers per corm as well as recurved leaves (vs. erect in C. tuna-ekimii ). Except for the flower color, C. tuna-ekimii most closely resembles C. sozenii from Simav (Kütahya). Although their leaf characters are very similar (usually 2, erect, to 4 mm wide, and many ribs to 7), the new species has yellow-orange (vs. violet-blue) flowers, chromosome number and karyotype formula 2n = 2x = 12 = 6m + 6sm (vs. 2 n = 2x = 8 = 4m + 4sm). Their morphological comparison is given in Table 1. Harpke et al. (2013) recognized three major testa surface types with subtypes. However, C. tuna-ekimii does not match exactly any of them, albeit close to Type 3. The seed surface of C. sozenii is very similar to C. tuna-ekimii ( Fig. 2 ). Differences in seed surface among taxa belonging to different C. sect. Crocus series was mentioned by Kerndorff et al. (2015). A quite similar plant is currently stored in E herbarium (E00333345!), under the name C. chrysanthus . It was collected from Simav (Akdağ) by Coode & Jones in 1965. Detailed field studies should be carried out to establish the identity of this specimen, which may pertain to C. tuna-ekimii .

from literature ( Rukšāns 2015 & 2017) and specimens collected from type locality.

Figures

FIGURE 1. Crocus tuna-ekimii. a: habit. b: anthers and three-branched style (tepals removed). c: leaf cross-section and ribs in lateral channels. d: corm tunics. e:flower. f: mature capsule. g: seeds.

FIGURE 2. SEM images of the seed surface. a, b, c: C. tuna-ekimii. d, e, f: C. sozenii.

FIGURE 3. Somatic chromosomes and karyotypes. a, b: C. tuna-ekimii. c, d: C. sozenii.

FIGURE 4. Habitat of C. tuna-ekimii. a: habitat. b: a group of C. tuna-ekimii on the marble bedrock. c: from left to right; C. tuna-ekimii, C. flavus subsp. dissectus, Galanthus gracilis and C. tuna-ekimii.