Silene linearis Decne., Ann. Sci. Nat. Bot. ser . 2, 3: 276. 1835, nom. cons. prop. (in press) [non Sweet].

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

3. Silene linearis Decne., Ann. Sci. Nat. Bot. ser. 2, 3: 276. 1835, nom. cons. prop. (in press) [non Sweet].

Type.

[Egypt], Hab. le désert du Sinaï, [1.6.1832], N. Bové 178 (lectotype, designated here: G! [G00226732]; isolectotypes: K! [K000728452], G! [G00226733]).

Description.

15.0-60.0 cm tall, erect or spreading. Stem pubescent in lower part, scabrous, glabrous but with sessile glands in upper part; with 6-10 distinct internodes, the uppermost internode length 3.0-6.0 cm long and obviously longer than the next upper internode. Basal leaves oblanceolate 30.0-60.0 × 2.0-4.0 mm, pubescent. Cauline leaves linear or lanceolate 10.0-55.0 × 1.0-4.0 mm, pubescent. Calyx 11.0-19.0 mm long, campanulate at anthesis and clavate in fruit, pubescent; teeth unequal; shorter ones 1.5-2.0 mm, ovate, mucronate; longer ones 2.0-2.5 mm, ovate, acuminate; marginal hairs short (up to 0.5 mm), dense. Inflorescence non-divaricate, branch axile (much) less than 90°. Petal claws 6.0-7.0 mm long, glabrous; limbs 6.0-8.0 mm long, divided, upper-surface white, lobes linear or oblong, divergent, petal limbs cleft to middle or more, lower-surface green; coronal scales 1.0-2.5 mm long, obovate, apex dentate. Anthophore 8.0-11.0 mm long, densely puberulent. Anthers exserted; filaments 8.0-9.0 mm long, glabrous. Styles exserted. First pedicel 1.0-3.0 cm in flower, 2.0-4.0 cm in fruit, erect, glabrous, apex antrorse. Capsule 5.0-7.0 mm long, ovoid or ellipsoid, fragile, opaque. Seeds 0.7-0.9 mm wide, 0.6-0.7 mm high, testa smooth.

Distribution.

E Egypt (Red Sea area, Sinai), N Arabian Peninsula, W Jordan and Palestine (Fig. 7 ).

Notes.

Silene linearis has some superficial similarity to S. austroiranica , which has narrowly lanceolate calyx teeth with narrow transparent margin, and not the broad rounded margin of S. linearis (see Fig. 6 ). Silene austroiranica is allopatric and found further south and east on the Arabian Peninsula, and in eastern Iraq and western/southern Iran.

The ranges of the calyx, anthophore and capsule lengths are unusually large in S. linearis . The large-flowered individuals are all found in Egypt (although not all specimens from Egypt are large-flowered), with calyx length of 17-19 mm (and proportional anthophores and capsules). The specimens are in all other respects similar (or perhaps with slightly shorter mucro on calyx teeth) to the S. linearis specimens with smaller flowers, and we do not think the difference is sufficient to merit taxonomic recognition. The Egyptian specimens are in general (independent of flower size) tomentose to villous while the specimens from Palestine and Jordan are often slightly puberulous, although at least one specimen from Palestine is densely tomentose.

One sequence for a specimen from Egypt ( S. linearis , ID 49, KX757593) is included in the ITS tree. It forms a strongly supported clade together with the other two S. linearis accessions (PP = 1.00 MPB = 96% MLB = 93%, Fig. 3 ). The S. linearis clade (with the two Palestine accessions) is strongly supported in all trees (PP = 1.00, Fig. 1 ; PP = 0.95 MPB = 75% MLB = 95%, Fig. 4 ; PP = 1.00 MPB = 100% MLB = 100%, Fig. 5 ).

Nomenclatural notes.

The name Silene linearis Decne. has been used for a long time, but the delimitation of the taxon has varied. A number of authors have used the name in our sense, e.g. Boissier (1867), Rohrbach (1868), Williams (1896), Post (1932), Chowdhuri (1957), Mouterde (1966), Zohary (1966), Chamberlain (1996) and Boulos (1999). Other authors use this name for a more inclusive taxon, e.g. Rechinger (1964) and Blakelock (1957), including S. leyseroides , S. arenosa , S. chaetodonta and S. kotschyi Boiss. (= S. microsperma ). Sweet (1830) used the epithet " linearis " in Hortus Britannicus 2nd ed., in a completely different context, five years earlier than Decaisne’s description was published. The name Silene linearis Sweet has been cited by few authors. Rohrbach (1868) referred to the name as a synonym for Silene cucubalus Wib. (= Silene vulgaris (Moench) Garcke) and Marsden-Jones and Turrill (1957) recognized the name as a part of the Silene vulgaris -assemblage but used the name in a highly informal way. The name is not mentioned in Chater et al. (1993), Aeschimann (1985), Pignatti (1982) or Greuter et al. (1984). Silene linearis Decne. has been suggested to be conserved against Silene linearis Sweet (Eggens & al., in press).

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 6. Different types of calyx teeth. A Silene linearis (M. Bierkamp & P. Zinth 177 BSB) B Silene austroiranica (Rechinger 10772 B) C Silene corinthiaca (B. Oxelman 1934 GB) D Silene georgievskyi (Rechinger 9828 B). A, B and D are representatives of S. section Arenosae. Illustrations by F. Eggens.

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.