Crocus asymmetricus Erol, 2020

Çiftçi, Almila, Harpke, Doerte, Mollman, Rachel, Yildirim, Hasan & Erol, Osman, 2020, Notes on Crocus L. Series Flavi Mathew (Iridaceae) and a new species with unique corm structure, Phytotaxa 438 (2), pp. 65-79 : 74-75

Crocus asymmetricus Erol sp. nov.

Crocus asymmetricus is similar to C. antalyensis . It is easily distinguished from C. antalyensis by its asymmetric corm and lack of long, persistent neck of old cataphylls at the apex.

Type:— TURKEY. Maraş: border of Maraş – Osmaniye, Ceyhan Valley 850–920m a.s.l., 6 March 2019, Mehmet Çelik s.n. (holotype ISTF 41370!, isotype: EGE!)

Corm ovoid-globose, asymmetric when mature, 8–18 mm in width (mean 12.28 ± 2.5; n = 17) × 11–19 mm in length (mean 15.52 ± 2.6; n = 17); roots emerge from one side. Corm tunics coriaceous to membranous, split into narrow bands or triangles from base, rings absent; neck narrow sharp triangular teeth, 1.79–4.52 mm long (mean 3.17 ± 0.9; n = 17). Cataphylls 2-3, white, dried cataphylls white. Prophyll absent. Bract and bracteole present, conspicuous, silvery white. Leaves synanthous, 3–8, usually 5 (mean 4.83 ± 1.09; n = 18), green, elongate lanceolate, 0.84–3.06 mm in width at broadest (mean 1.8 ± 0.5; n = 18), white stripe usually 1/2 of leaf diameter, 0.33–1.07 mm (mean 0.76 ± 0.2; n = 18), without ribs, glabrous. Perianth tube creamy white (yellow on herbarium specimens) with purple stripes. Flowers star-shaped, perigone segments elliptic, obtuse to subacute, outer segments 19–30 mm long (mean 25.31 ± 3.4; n = 13), 4–9 mm wide (mean 7.4 ± 1.4; n = 13). Inner segments 20–28 mm long (mean 23.9 ± 2.3; n = 13) and 5–10 mm wide (mean 7.47 ± 1.9; n = 13). Segments purple on inside, outer segments dull lilac-white on abaxial side with three distinct purple stripes and featherings, inner segments purple, sometimes with one inconspicuous purple stripe and featherings. Throat bright yellow, glabrous. Filaments creamy, 3–6 mm long (mean 4.67 ± 1.05; n = 13), glabrous, anthers 9–14 mm long (mean 10.84 ± 1.5; n = 13), pale yellow, connective white. Styles orange, many branched, with long branches 5–10 mm long (mean 7.66 ± 0.71; n = 13). Styles always longer than stamens ( Fig. 3 ). Mature capsule and seed not observed. Flowering February. Chromosome number 2n = 2 x = 8 ( Fig. 5 ).

Etymology:—The species epithet is derived from the asymmetric corm of the new species. The Turkish name given to the species is “Karacaoğlan çiğdemi” according to the guidelines laid out by Menemen et al. (2013). Karacaoğlan was a folk poet who lived near the type locality of C. asymmetricus in 1700s.

Taxonomic relationships: — The asymmetric corm of Crocus asymmetricus is unique within the genus. Other corm tunic characters and the multifid stigma branches suggest that this species belongs to C. ser. Flavi . Prior to the discovery of this new species, the only species in series C. ser. Flavi showing lilac-blue flowers and multi-branched stigma were C. antalyensis and C. antalyensioides . These two closely related taxa are characterized by long, brown, persistent neck of old cataphylls at the apex ( Fig. 3 , Table 1), whereas the new species has deep lilac-blue flowers without persistent cataphylls ( Fig. 1 , 2 , Table 1). Besides its slightly asymmetric corms ( Figs. 2 , 3 ), C. asymmetricus shows another unique features, i.e. the arrangement of root emergence, where roots emerge from only one point rather than from around the basal node as in other species. Since its original description published in 1975 no one paid enough attention to the corm of C. adanensis . Indeed, after a careful observation of peeled corms (free from tunics) of this species we found that roots only emerge from the base of the corm in two or three bundles ( Figs. 6a, b ). This feature is shared with C. asymmetricus discovered in the Ceyhan valley. The ITS sequences of individuals of this population are also unique within the genus: eight substitutions and two indels distinguish it from the closest species C. vitellinus . Our phylogenetic analysis places the new species in a clade comprising C. vitellinus , C. graveolens , and C. hyemalis (pp = 1) ( Fig. 4 ). Morphologically, C. asymmetricus can be distinguished from the latter four species by its flowers color in addition to the unique corm shape and root emergence ( Table 1, Fig. 1 ).

All species of C. ser. Flavi with the exception of C. hyemalis are part of the Turkish flora. A new identification key for species occurring in Turkey is presented below (the two subspecies of C. antalyensis are excluded, but a key for them was provided by Erol et al. 2011).

Figures

FIGURE 1. Crocus asymmetricus from its locus classicus: habit (A, B); peeled corm (C); corms with tunics (D).

FIGURE 2. Illustration of C. asymmetricus: A. Habitus; B. Flower dissection; C. Leaf cross section; D. Corm: D1. General view, D2. Young (above) and mature corm (below); E. Corm tunics (E1 and E2); F. Basal tunic. Drawing made from specimen ISTF 41370.

FIGURE 3. Illustration of Crocus antalyensis: A. Habitus; B. Flower dissection; C. Leaf cross section; D. Corm: D1. General view, D2. Young (above) and mature (below) corm; E. Tunics (E1, E2, E3). Drawing made from specimen ISTF 41144.

FIGURE 4. Phylogenetic tree obtained by Bayesian inference of the nuclear rDNA ITS. Numbers along branches are posterior probabilities.

FIGURE 5. Mitotic metaphase plate with 2n = 8 chromosomes (a), and idiogram (b) of C. asymmetricus. Scale bar = 10 µm.

FIGURE 6. Corm of C. adanensis: basal view (a), side view (b).