Dichodon kotschyi (Boissier) Ikonnikov, Novosti Sist. Vyssh. Rast., 1973

Arabi, Zahra, Ghahremaninejad, Farrokh, Rabeler, Richard K., Sokolova, Irina, Heubl, Günther & Zarre, Shahin, 2018, On the taxonomic status of the genus Dichodon (Caryophyllaceae: tribe Alsineae): morphological and molecular evidence reassessed, Phytotaxa 360 (3), pp. 220-236 : 231

Dichodon kotschyi (Boissier) Ikonnikov, Novosti Sist. Vyssh. Rast. 10: 142. 1973 ≡ Cerastium kotschyi Boissier

(1867: 715) ≡ Arenaria kotschyi ( Boissier 1867: 715) Shinners (1962: 50) ≡ Cerastium viscidus var. kotschyi ( Boissier

1867: 715) Mouterde (1966: 477) ( Fig. 1A–B ).

Type (lectotype, designated here):—ANTILIBANON [ SYRIA]: circa Zebdaine prope Damascum, in madidis as fontes supra Bludan, alt. 5000’, 14 June 1855, Kotschy 128 [G!, isolectotypes: BM, BM000595327! (https://plants.jstor.org/stable/history/10.5555/al.ap. specimen.bm000595327), MPU, MPU013768!(https://plants.jstor.org/stable/10.5555/al.ap.specimen.mpu013768), K, K000723534! (http://apps.kew.org/herbcat/getImage.do?imageBarcode=K000723534, as C. anomalum Schrank (1795: 73) ].

= Dichodon schischkinii ( Grossheim 1950: 9) Ikonnikov (1973: 142) ≡ Cerastium schischkinii ( Grossheim 1950: 9) , syn. nov.

Type (lectotype, designated here):—AZERBAJDZHAN [ Azerbaijan]: Republica Autonoma Nachitschevan, distr. Schachbuz, in trajecto Bitschenach, ca. 2500 m, in pascuis, 16 June 1947, Grossheim, Iljinskaia & Kirpitcznikov s.n. ( LE!, barcode LE 01042957).

Description:—Annual plants, erect, covered with glandular hairs in upper parts. Taproots slender. Stems single, sometimes branched from the base dichotomously, lacking the aggregation of basal leaves. Leaves linear to narrowly lanceolate, light green, non-succulent. Inflorescences 3 to many-flowered, axillary inflorescences sometimes present. Bracts similar to the leaves, without scarious margins. Pedicels usually short, the lowest ones 1.5–2.5 times longer than sepals, the others equal to or shorter than sepals, congested to some extent, and erect. Petals white, slightly exceeding sepals, not deeply notched. Styles 3(4). Stamens 10. Sepals lanceolate, with wide scarious margins, glandular, purpletinged. Capsules cylindrical, mostly as long as sepals with short horizontally reclined or patent teeth. Seeds many, ovate, greyish yellow, 0.7–0.8 mm diam., verrucate on surface.

Typification of Cerastium kotschyi :— Four sheets numbered with “128” and collected by Kotschy “prope Bludan”, as reporetd in the protologue, were found at BM, G-BOIS, K and MPU. These specimens are syntypes (Art. 9.5 of ICN), and as a consequence, a lectotypification is necessary (Art. 9.1 of ICN). G-BOIS specimen is here designated as the lectotype, the other ones at BM, K, and MPU are isolectotypes.

Typification of Cerastium schischkinii :— The citation of the type in the protologue ( Grossheim 1950: 10) runs as follows: “Azerbajdzhan, respublica autonoma Nachitschevan, distr. Schachbuz, in trajecto Bitschenach ca. 2500 m, in pascuis 16 VI 1947, fl., fr., A. Grossheim, I. Iljinskaja et M. Kirpitcznikov. In Herb. Inst. Bot. nom. ac. V. L. Komarovii Ac. Sc. URSS in Leningrad conservatur”. No specimen, however, with the label in perfect agreement with the protologue was found in the collections of LE. Deposited in LE there are 6 sheets labelled as: “ Azerbaijan, Nakhichevan Autonomous Republic, Shakhbuz District, slopes of Batabat-dag Mt. above Bichenakh pass, 2350–2450 m a.s.l., alpine pastures, Grossheim, Iljinskaja, Kirpicznikov” (originally in Russian) are available in LE, 5 of them with the same collection date as in the protologue (16 June 1947), and one sheet without any date. All the specimens are determined by Grossheim as “ Cerastium schischkinii sp. nova ” in August 1948 and tagged as “Specimen authenticum” with a handwritten note “Cotypus!” by Grossheim. In addition, two sheets labelled as “ Azerbaijan, Nakhichevan Autonomous Republic, Bichenakh village, ca. 1800 m a.s.l., forest limits, wet depression, 28 V 1947, Grossheim, Iljinskaja, Kirpicznikov” are deposited in the herbarium LE. These are also determined by Grossheim as “ Cerastium schischkinii sp. nova ” in August 1948, and one of them is tagged as “Specimen authenticum” with the handwritten “Typus!” by Grossheim. We consider all the cited specimens as original material of the name, and choose the lectotype from among the ones collected on 16 June 1947, as their labels agree with the protologue in more detail (locality, date, habitat).

Taxonomic notes:— Dichodon kotschyi can be distinguished from D. viscidus by its non-succulent, linear to narrowly linear leaves, single to dichotomous stems, petals as long as sepals or slightly longer than sepals, and capsules mostly as long as sepals with patent capsule teeth. These characters and distribution of the specimens in lower elevation of Damavand correspond well with Grossheim’s description of Cerastium schischkinii , but the result of the phylogenetic analysis together with morphological evidence confirm C. schischkinii as a synonym of D. kotschyi .

Conservation status:— Dichodon kotschyi has a wide distribution range starting from high altitudes (> 2500 m) western from Syria, Turkey, Caucasus region and northwest to north Iran. Similar to D. alborzensis it is restricted to wet meadows that are subjected to lower precipitation leading to reduced individuals and populations of this species. In Iran we found about 100 individuals of this species in each locality in Prov. E Azerbaijan and Prov. Tehran, each locality with several patches (ca. 20 individuals in each patch). This species can be classified as the category Near Threatened (NT) according to the IUCN system ( IUCN 2017).

Selected specimens:— IRAN. Prov. East Azerbaijan: Tabriz, Almalou Gul , 2450 m, N 46.631944 E 37.664722, 16 August 2016, Arabi 47419 ( TUH) ; Prov. Tehran: North Tehran, Mt. Damavand , southern slopes, 3450 m, 02 July 2016, Arabi 47423 ( TUH) .

Figures

FIGURE 1. Representatives of three Dichodon spp. from Iran in different locations. A–B: D. kotschyi in Prov. Azerbaijan, 2450 m; C–D: D. kotschyi in Prov. Mazandaran, 3450 m; E–F: D. alborzensis in Prov. Mazandaran, 4200 m; G–H: D. alborzensis in Prov.Alborz, 2500 m; I–J: D. alborzensis Tehran, 3700 m; K–L: D. persicus in Prov. Hamedan, 2500 m.