Silene arenosa K.Koch, Linnaea 15: 711. 1841.

Eggens, Frida, Jafari, Farzaneh, Thollesson, Mikael, Crameri, Simon, Zarre, Shahin & Oxelman, Bengt, 2020, Phylogeny and species delimitation in Silene sect. Arenosae (Caryophyllaceae): a new section, PhytoKeys 159, pp. 1-34 : 1

1. Silene arenosa K.Koch, Linnaea 15: 711. 1841.

= Silene kowalenskyi Stschegl., Bull. Soc. Nat. Mosc. 26: 322. 1853. - Type: Tab. V.f.1. (neotype designated here: [Azerbaijan] Inter Nachitschevan et Ordubad, Kowalensky s.n. G-BOIS! [G00544651])

Type.

[Azerbaijan], Prope flumen Araxin in arena frequenter, [1837, 1838], K.Koch 873 (lectotype, designated by Lazkov in Caucasian Flora conspectus 3(2): 208. 2012, LE! [LE01051368]; syntypes: [Azerbaijan], Araxon, annu 1838, LE! [LE01051369]; B destroyed?).

Description.

(5.0-)10.0-30.0 cm tall, spreading or rarely erect. Stem papillate throughout, pubescent in lower part, glabrous but with sessile glands in upper part; with 2-3 distinct internodes, the uppermost internode1.5-4.0 cm long and obviously longer than the next upper internode. Basal leaves oblanceolate, glabrous. Cauline leaves linear or lanceolate 10.0-40.0 × 2.0-4.0 mm, glabrous or slightly papillate. Calyx 10.0-14.0 mm long, cylindrical at anthesis and clavate in fruit, glabrous, slightly papillate; teeth unequal; shorter ones 1.0-1.5 mm long, ovate, mucronate; longer ones 1.5-2.0 mm, ovate, acuminate; marginal hairs short (up to 0.5 mm), sparse. Inflorescence non-divaricate, branch axile (much) less than 90°. Petal claws 6.0-7.5 mm long, glabrous; limbs 2.0-3.0 mm long, emarginate or bifid, upper-surface pink, lobes linear, petal limbs cleft to middle or more; coronal scales 0.4-0.5 mm long, ovate, apex entire. Anthophore 4.0-5.0 mm long, glabrous. Anthers exserted; filaments 7.0-8.0 mm long, glabrous. Styles exserted. First pedicel 1.0-3.0 cm in flower, 2.0-3.5 cm in fruit, spreading, glabrous, apex mostly geniculate or antrorse. Capsule 6.0-8.0 mm long, oblong or ellipsoid, fragile, opaque. Seeds 0.5-0.8 mm wide, 0.5-0.7 mm high, testa smooth.

Distribution.

Armenia, Azerbaijan (Nachitchevan), NW Iran (Fig. 7 ).

Notes.

The two accessions form a strongly supported clade in all trees (PP = 1.00, Fig. 1 ; PP = 1.00 MPB = 100% MLB = 100%, Fig. 3 ; PP = 1.00 MPB = 98% MLB = 98%, Fig. 4 ; PP = 1.00 MPB = 99% MLB = 100%, Fig. 5 ). Despite its geographical, morphological and phylogenetic distinctiveness, this taxon has been confused with S. leyseroides ( Melzheimer 1988: as synonym, Schischkin 1936). The two species are superficially similar; both have spreading stems and pedicels that are upturned (or geniculate) at apex in fruit, so that all capsules are vertical although the pedicel may be almost horizontal. However, S. arenosa is readily distinguished by the shorter, mucronate and sparsely ciliate (not acuminate and densely ciliate) calyx teeth and the glabrous anthophore from S. leyseroides . It also has smaller petals that are almost completely included within the calyx, and the petal limb is sometimes emarginate rather than bilobed. We have not seen any material of S. arenosa from any other area than Armenia, Azerbaijan (more specifically the region Nachitchevan), and Iran (close to the borders to Armenia, Turkey, and Nachitchevan), whereas S. leyseroides appears to be allopatric and grows mainly in the Zagros Mountain range and in E Afghanistan/NW Pakistan (see Fig. 7 ).

The seeds of S. arenosa are possibly more shining on the surface, instead of the greyish, dull surface that is the common condition for Silene seeds, but we have seen too few specimens with seeds to draw definitive conclusions. The green midpart of the calyx teeth is narrow, which can make the teeth look lanceolate rather than ovate. Collections from near the border between Iran and Turkey have calyces which are densely papillose in upper parts.

Figures

Figure 1. Species tree from two STACEY runs and three unlinked regions (ITS, RPB 2, rps 16). Posterior probabilities> 0.75 are shown above branches. The number following the taxonomic name is the specimen ID (Suppl. material 1). Scale bar reflects the number of substitutions per site.

Figure 3. Phylogenetic tree resulting from Bayesian analysis of the ITS sequences including 76 taxa. The trees were summarized in a 50 % majority-rule consensus tree with the posterior probabilities (PP) indicated above branches. Bootstrap support values (> 75 %) based on MP and ML are noted below branches, respectively. The numbers following the taxonomic name indicate the specimen ID and Genbank numbers (Suppl. material 1), respectively.

Figure 4. Phylogenetic tree resulting from Bayesian analysis of the rps 16 sequences including 71 taxa. The trees were summarized in a 50 % majority-rule consensus tree with the posterior probabilities (PP) indicated above branches. Bootstrap support values (> 75 %) based on MP and ML are noted below branches, respectively. The numbers following the taxonomic name indicate the specimen ID and Genbank numbers (Suppl. material 1), respectively.

Figure 5. Phylogenetic tree resulting from Bayesian analysis of the RPB 2 sequences including 76 taxa. The trees were summarized in a 50 % majority-rule consensus tree with the posterior probabilities (PP) indicated above branches. Bootstrap support values (> 75 %) based on MP and ML are noted below branches, respectively. The numbers following the taxonomic name indicate the specimen ID and Genbank numbers (Suppl. material 1), respectively.

Figure 7. Distribution map of S. sect. Arenosae. Each color code corresponds to one taxon: A S. arenosa B S. austroiranica C S. chaetodonta D S. exsudans E S. georgievskyi F S. leyseroides G S. linearis H S. microsperma subsp. cypria I S. microsperma subsp. maritima J S. microsperma subsp. microsperma K S. microsperma subsp. modesta L S. striata.