Clematis iranica Habibi, Ghorbani & Azizian, 2014

Clematis iranica Habibi, Ghorbani & Azizian View in CoL sp.nov. ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 )

Similis ab Clematis orientalis differt ruentes virgultum, folia 1–2 pinnata , viridi, sub coriaceis, variabilis in figura, ellipticolanceolatis, ad ovatis-lanceolatis interdum lanceolatis.

Type:— IRAN. Mazandaran Province, Noor, Baladeh-Uoosh , on rocky slopes, along rivers, 2100 m, 2 December 2006, M. Habibi, M. Ghorbani & M.H. Heidary. SBUH:8500087 (Holotype SBUH , Isotypes TARI , IRAN , MPIH ).

Scrambling shrubs; branches shallowly sulcate, puberulent. Leaves 1–2 pinnate, with 5–13 leaflets, dark green, sub-coriaceous, variable in shape, elliptic-lanceolate to ovate- lanceolate or lanceolate, 17.0–60.0 × 7.0–31.0 mm, entire or more often trilobed or unevently bilobed, generally with a number of lesser or tooth like lobes at apex, acute or subacute lobes, at leaf base cuneate sometimes truncate, on both surfaces minutely puberulent, or nearly so, abaxial midrib surface slightly prominent. Petioles 23.0–34.0 mm long. Inflorescence cymes, axillary; peduncles 15.0–56.0 mm long, pubescent; bracts pinnate to unifoliate foliaceous. Flowers ca. 24.0–32.0 mm in diameter, pedicel slender, 15.0–39.0 mm long, pubescent. Sepals 4, yellow, spreading or reflexed, elipticlanceolate, 9.0–13.0 × 3.0– 4.5 mm, pubescent on both surfaces, with velutinous margin, acute apex. Stamens 6.0– 7.0 mm long; filaments 4.0–5.0 mm long, purplish, pubescent; anthers narrowly oblong, 2.0–3.0 mm long, glabrous, apex obtuse. Styles 5.5–7.5 mm long, densely villous. Achenes narrowly oblong, ca. 2.8 × 1.2 mm, puberulent, slightly rimmed; persistent styles, 2.5–5.5 cm long, plumose.

This species is closely related to C. orientalis . Thus, comparisons between these two species are presented here through text, tables and figures.

Habitat, ecology and phenology:— Clematis iranica occurs in Northern, Northwestern and Northeastern Iran. This species is observed along with C. orientalis in most of these areas. They usually appear on elevations between 1400 and 2200 m in small populations on rocky slopes, along rivers and streams of water shrubberies and hedges. It flowers and fruits from June to July.

Etymology:— The species epithet is derived from the word “ Iran ”, where the type specimen was collected.

Discussion:— Clematis iranica belongs to a natural group of scrambling shrubs. This group consists of more than 12 species worldwide, including C. orientalis ( Grey-Wilson 1989, Wang 2006). Clematis iranica is morphologically close to C. orientalis , treated under the sect. Meclatis ( Spach 1838: 272) Baillon (1867: 57). Clematis iranica has the following characters in common with other members of sect. Meclatis ( Grey-Wilson 1989, Brandenburg 2000, Wang 2006): yellow or greenish-yellow flowers and the pubescent dilated filaments, together with the pubescent achenes and styles. However, it differs from other species in the section by its scrambling, shrubby habit.

The new species is allied to Clematis orientalis . These species are sympatric in Iran, despite showing some differences in their vegetative and reproductive features. Clematis iranica has a scrambling habit, 1–2 pinnate leaves with a dark green color, oblate-lanceolate, ovate-lanceolate or lanceolate shape, and acute to acuminate apex. Clematis orientalis has a woody vine habit, one pinnate leaf with a grey-green color, oblate-ovate or ovate cauline leaves, and an obtuse apex ( Table 1 View TABLE 1 ). Additionally, palynological, anatomical and cytological comparisons were carried out on these two species. The pollen morphology was studied using scanning electron microscopy (SEM) and some differences were demonstrated in the pollen shape. The general shape of pollen grains in C. iranica is equiprolate in equatorial plain and rounded in polar view, whereas the other species has prolatespheroidal in equatorial and rounded in polar view pollen grains ( Fig. 3 View FIGURE 3 , Table 2 View TABLE 2 ).Furthermore, the epidermal cells in C. iranica are irregular in shape with slightly undulate anticlinal walls, while they are regular with straight to curved anticlinal walls in C. orientalis ( Fig. 4 View FIGURE 4 , Table 2 View TABLE 2 ). Mitotic karyotype analyses in the studied species and populations of Clematis , revealed the presence of 2n= 2x= 16 chromosomes in both species. The studied species are different in their karyotypic formula, and these differences are presented in Fig. 5 View FIGURE 5 and Table 2 View TABLE 2 .

Clematis iranica seems to be most closely related to C. orientalis sensu stricto.

This close relationship is evident particularly in reproductive features such as inflorescence type, sepal shape and sepal color. The observed differences are listed in Tables 1 View TABLE 1 and 2 View TABLE 2 . These differences are more important because these species are sympatric while they show large seasonal reproductive segregation.