Campanula persepolitana Kotschy ex Boiss., Diagn. Pl. Orient.

Zeraatkar, Amin & Nasab, Farzaneh Khajoei, 2023, Taxonomic notes on some species of Campanula, sect. Oreocodon, Phytotaxa 618 (3), pp. 283-290 : 286-289

Campanula persepolitana Kotschy ex Boiss., Diagn. Pl. Orient. ser. 1, 7: 19 (1846). ( Figs. 1 , 3–7 )

Type:— Persia [ Iran]: Kotschy, K. G. T., 861, G!.

Description:— Plants annual, small, fragile, cespitosa and chasmophyte. Stems branched (simple), ascending, flexuous, fragile, (0) 0.7–3 cm long, arising from the collar of a thin tap-root, glabrescent or sparsely with simple villous hairs up to 2 mm long. Leaves reniform, 0.4–2.8 (3) cm in diam., margin slightly to obviously dentate, sometimes repand, subentire or entire, cordate at base, glabrescent, or covered with very sparsely simple hairs (usually short, up to 0.5 mm long) on both sides, to glabrous; petioles thin, 0.7–13 cm long, glabrescent or covered with sparsely simple hairs, up to 2 mm long. Inflorescence small, corymb, 1–7 cm long, distinctly leafy. Pedicel thin, filiform, 0.5–7 cm long, ascending to erect, purple, glabrescent or covered with sparsely to moderately simple hairs, up to 2 mm long. Calyx lobes lanceolate, to linear-lanceolate or subulate, (1.5)2–2.5(3) × 0.2–0.3 mm, ascending, acute, narrowly acute (rarely obtuse) at apex, glabrous, villous at margin, or glabrescent, glabrescent at fruiting time; appendage absent. Corolla tube narrowly cylindrical to campanulate, white (rarely white with pale blue midribs and lobes), 9–10 × 2–5 mm, glabrous, divided to 1/5 tube; corolla lobes 2–2.5 × 1–1.5 mm, elliptic to widely ovate, obtuse; appendage absent. Style included in the corolla tube or equal to it, 5–5.5 mm long, white, glabrous, straight. Stigmas 3, usually fused, sometimes distinct, slightly recurved or straight, c. 2 mm long. Stamens c. 4 mm long; filament white, 2–3 mm long, with triangular base, base of filament c. 2 × 0.5 mm, glabrous; anthers yellow, c. 2 mm long; pollen grains bright yellow. Ovary glabrous, shiny green. Capsule narrowly elliptic shaped, c. 2.5–4 mm long, glabrous, opening by 3 basal pores. Seeds numerous, narrowly ellipsoid, 0.5–0.7 × 0.2–0.3 mm, yellow to rarely blue, shiny; surface ornamentation striate.

Habitat and ecology:—Both species are either chasmophytes or chomophytes and cannot grow in full sun and are adapted to semi-humid regions. C. perpusilla is distributed on vertical limestone, sandstone or conglomerate and overhanging rocks while C. persepolitana grows on limestone crevices ( Figs. 2–6 ).

Taxonomic and distributional remarks: —Two species Campanula persepolitana and C. perpusilla are closely related Iranian Campanula species which have some identical morphological traits such as reniform leaves and long pedicels and petioles ( Figs. 4 & 5 ). Previous studies have concluded that the morphological differences between the two species are minimal ( Rechinger & Schimann-Czeika 1965, Aghabeigi 2010). Furthermore, the studies indicate that the identities of these species need to be assessed through more collections and field studies of their populations. On the other hand, until the present study C. persepolitana was known only in a few localities close to the type location. Here, a careful examination of living plant species, as well as herbarium specimens of these two species, revealed they are distinct species. The corolla of C. perpusilla is always white with deep blue lobes whereas it is white on C. persepolitana (very rarely white with pale blue lobes). It is important to refer that the color of the corolla is obscureor little known to date ( Rechinger & Schimann-Czeika 1965, Aghabeigi 2010) and the first photographic documentation of the living plant in its habitat is presented here. Moreover, they can be distinguished from each other by the corolla structure. C. persepolitana has a longer corolla and the shape of corolla lobesvaries (divided into 1/5 tube vs 1/6; elliptic to widely ovate, obtuse vs widely ovate, acute or acute-obtuse) ( Fig. 5 ). Indumentum characters appear to have taxonomic significance and have been used in species delimitation of the genus ( Abdollahfard et al. 2022). Previous studies have concluded that the only reliable difference between the two species is the presence (in C. persepolitana ) and the absence ( C. perpusilla ) of trichomes ( Rechinger & Schimann-Czeika 1965, Aghabeigi & Assadi 2008, Aghabeigi 2010). Our extensive study of a variety of specimens and living materials in their range shows that C. persepolitana is always hairy, compared with the hairy and hairless forms frequently found within the same C. perpusilla populations. Both species have simple, needle-shaped and flatted trichomes. In addition, trichomes are more common and longer on pedicels and also petioles, compared with leaves that are usually glabrescent, sparse or glabrous, and shorter. Although, C. persepolitana have longer trichomes (up to 2 mm compared with 0.4 (1) mm in C. perpusilla ) ( Fig. 6 ). Seed color is another diagnostic feature between species ( Fig. 7 ). Finally, the two species are quite geographically separated. C. persepolitana is a vulnerable species and appears to be restricted to the rock crevices of mountains in NW Fars province, and represents one of the narrow endemics of the Irano-Turanian region in Iran. C. perpusilla has a wider range and is found mainly at low altitudes in western and southwestern Iran and in a small area of Iraqi Kurdistan ( Fig. 1 ).

Among all known species of the sect. Oreocodon (Fed.) Ogan. only C. persepolitana and C. perpusilla are annual. While these two species were known as perennial in the Campanula treatment for Flora of Iran ( Aghabeigi 2010) and Flora Iranica ( Rechinger & Schimann-Czeika 1965) and the recent revision of the genus in Iran ( Aghabeigi & Assadi 2008).

Asyneuma persicum Bornm.,Beih. Bot. Centralbl., Abt. 2. 38(2): 347 (1921).

Campanula hystricula Pau, Trab. Mus. Nac. Ci. Nat., Ser. Bot. No. 14, 37 (1918). syn. nov.

Holotype:—Persia [ Iran]: Kouh-Sefid (Alto Karun [River]), 3000–3500 m, Martínez de la Escalera, 5 June 1899 ( MA 121236 !).

Campanula hystricula is another species described by Pau from the Bakhtiari Mountains based on only one flowering specimen ( Pau &Vicioso 1918). The species has remained a mystery for over a century and in the few publications mentioning the species name, including Flora of Iran and Flora Iranica, and no attempt has been made to clarify this item.

After examining the voucher specimens and type locality, we found that it is actually Asyneuma persicum Bornm. due to many characteristics including corolla cleft for 2/3–3/4 of its length; style longer than corolla; basal leaves of lanceolate, with entire, subentire and slightly dentate margin; cauline leaves of linear-lanceolate to oblong-lanceolate, sessile or subsessile, strigose; linear bracts etc.

Asyneuma persicum is a common species in the Zagros Mountains , Turkey and Iraq. It is a common species in the highlands (including the upper forest belt) of Zagros, mostly with the cushion-tragacanthic communities. Depending on various environmental factors and the different vegetation types within its range, A. persicum exhibits a wide range of phenotypic plasticity ( Aghabeigi 2010).

Figures

FIGURE 1. Distribution of Campanula perpusilla (circle) and C. persepolitana (triangle).

FIGURE 2. Habitats of Campanula perpusilla. Conglomerate (a,b) and rocky mountains (c,d). Photograph by A.Z.

FIGURE 3. Habitats of Campanula persepolitana. Photograph by A.Z.

FIGURE 4. Campanula perpusilla (a) and C. persepolitana (b) in vegetative stage. Photograph by A.Z.

FIGURE 5. Campanula persepolitana (a,b) and C. perpusilla (c,d) in flowering time. Photograph by A.Z.

FIGURE 6. Trichomes on pedicels of Campanula perpusilla (a) and C. persepolitana (b). Scale bars: 1 mm. Photograph by A.Z.

FIGURE 7. Seeds of Campanula persepolitana (a–f) and C. perpusilla (g,h). Scale bar: 1 mm. Photograph by A.Z.