Rhanteriopsis baskilensis Hamzaoğlu & Behçet, 2022

Hamzaoğlu, Ergin & Behçet, Lütfi, 2022, Rhanteriopsis baskilensis sp. nov. (Inuleae, Asteraceae), a new species from Turkey, Phytotaxa 539 (1), pp. 33-44 : 35-42

Rhanteriopsis baskilensis Hamzaoğlu & Behçet , sp. nov. ( Figs. 1−6 ).

Type:— TURKEY. Elazığ: Baskil district , between İçlikaval and Şahindere villages, between 1500 and 1640 m a.s.l., rocky areas, 22.07.2021, L.Behçet 20517 (holotype GAZI, isotype Bingöl University Faculty of Arts and Sciences Herbarium) .

Diagnosis:— Rhanteriopsis baskilensis differs from R. microcephala by the stems entirely (vs. only apically) densely woolly, outer involucral bracts 0.4–0.7 (vs. 1.2–2.6) mm wide; inner involucral bracts 0.2–0.4 (vs. 0.8–1.2) mm wide; paleae 0.2–0.3 (vs. 0.5–0.9) mm wide; pappus consisting of 5 (vs. 2–4) bristles.

Description:—Caespitose perennials, entirely densely white-woolly, with thick woody root-stock, covered with remains of petioles. Stems 15–25 cm tall, erect to ascending, sometimes branched in upper part, completely leafy. Sterile shoot leaves oblanceolate, long petiolate, 3–10 × 0.5–1.5 cm. Cauline leaves elliptic to oblanceolate, entire, acute to rounded, attenuate at base; lower ones long petiolate, 3–6 × 0.6–0.8 cm; upper ones comparatively short petiolate or ± sessile, 1–3 × 0.2–0.6 cm. Capitula homogamous, discoid, solitary, terminal. Involucre broadly cyathiform, 9–11 mm in diameter. Involucral bracts 3–4-seriate, white-woolly; outer bracts linear to lanceolate, 5–6 × 0.4–0.7 mm; inner bracts oblong to linear, glabrescent in lower part, 5–6 × 0.2–0.4 mm, ciliate. Paleae narrowly oblong to sublinear, 5–6 × 0.2–0.3 mm. Disc florets 5-lobed, 4–5 × 0.4–0.5 mm, corolla lobes and apical part of tube dorsally densely glandular. Pistil 5–6 mm long, stigma 0.9–1.2 mm long. Anthers 2.7–3.3 mm long, filament 1.2–1.5 mm long. Achenes 4-edged, 4–6-ribbed, oblong to linear, 1.5–1.7 mm long, sparsely hairy, apically strigose-hispid (ca. 0.5 mm). Pappus consisting of 5 bristles, flattened, with serrate margins, 3–4 mm long, dirty white.

Distribution and ecology:—Baskil district (Elazığ province, Turkey), in which the new species is distributed, is located in the Irano-Turanian phytogeographic region. Rhanteriopsis baskilensis grows on rocky areas between 1500 and 1640 m a.s.l. and was found in a single locality. According to Emberger (1955), the Baskil district is located in the semi-arid cold Mediterranean bioclimate area. Walter (1962) divided the Turkish part of the Irano-Turanian phytogeographic region into two parts and the Baskil district was included in the forest area dominated by deciduous trees. Although there are oak communities in patches in the area where the new species was collected, steppe and rocky areas also have an important place. In addition to Quercus infectoria Olivier (1801: 252) subsp. veneris (Anton Kerner) Meikle (1985: 1479) , Q. libani Olivier (1801: 290), there is also the distribution of Q. brantii Lindley (1840: 41) infrequently as oak species distributed in the area. The distribution of Celtis tournefortii Lamarck (1797: 138), Crataegus orientalis (Miller) Marschall von Bieberstein (1808: 387), Rhamnus pallasii Fischer & Meyer (1837: 46), Rosa pulverulenta Marschall von Bieberstein (1808: 399) in the area was determined as a shrub form. Other important taxa with distribution in the habitat where the new species develops can be mentioned as follows: Acantholimon acerosum (Willdenow) Boissier (1846: 80), Astragalus densifolius Lamarck (1783: 317), Asyneuma virgatum (Labillardière) Bornmüller (1921: 351), Atraphaxis billardierei Jaubert & Spach (1844: 14), Chrysophthalmum montanum (Candolle) Boissier (1849: 4) , Dianthus orientalis Adams (1805: 54), Eremogone ledebouriana (Fenzl) Ikonnikov (1973: 140), Helichrysum arenarium (Linnaeus) Moench (1794: 575) , Hypericum scabrum Linnaeus (1755: 25), Onosma alborosea Fischer & Meyer (1839: 38), Prangos pabularia Lindley (1825: 7), Silene arguta Fenzl (1842: 8), Stachys mardinensis (Post) Mill (1980: 57), Teucrium chamaedrys Linnaeus (1753: 565) and T. polium Linnaeus (1753: 566).

Taxonomic notes

In molecular phylogenetic studies, it was shown that the genus Rhanteriopsis is closer to the genus Chrysophthalmum Schultz Bipontinus (1843: 955) and included in a monophyletic group called the “ Inula complex” together with the genera Inula , Pentanema Cassini (1818: 74) , Carpesium Linnaeus (1753: 859) , Amblyocarpum Fischer & Meyer (1837: 30), Telekia Baumgarten (1817: 149) and Varthemia Candolle (1836: 473). The genus Rhanterium , with which Rhanteriopsis is morphologically similar, is included in the other monophyletic group, the “ Pulicaria complex”. Rhanteriopsis , unlike many taxa in the “ Inula complex”, carries capitula to the palea and has flattened pappus bristles ( Englund et al. 2009, Gutiérrez-Larruscain et al. 2018). Although Rhanteriopsis species are phylogenetically close to Chrysophthalmum , they are more similar to some Inula species (especially I. heterolepis Boissier (1856: 12) in Turkey) with their semi-bushy and usually densely hairy appearance ( Davis 1975, Grierson 1975, Wiklund 1987).

Rhanteriopsis microcephala and R. puberula are very similar species. These two species were separated by Wiklund (1987) using the pubescence ratio of branch tips and leaves and leaf length. Rhanteriopsis baskilensis is similar to R. microcephala in terms of pubescence and involucrum width, and to R. puberula in terms of leaf shape and dimensions. On the other hand, R. baskilensis is clearly distinguished from both species in terms of involucral bracts, paleae and achenes dimensions and pappus bristles number ( Figs. 1–6 , Table 1 ).

Petiolar remnants of dead leaves and long-stalked leaves are clustered on the lower parts of stems during the flowering period of R. baskilensis ( Fig. 1 ). Since only severed stems were found in the R. microcephala herbarium specimen (P02708934) studied here, it was not possible to determine the similarity of the base of the two species. In flowering specimens of R. puberula , the bases are bare, clustered dead petiolar remnants and long-stalked leaves are not observed.

Although the capitulum features (homogamous) of Rhanteriopsis baskilensis are generally similar to R. microcephala and R. puberula ; in R. baskilensis , invulocral bracts are 3–4-series (not 2–3-series). Rhanteriopsis baskilensis is in agreement with the current description of the genus in terms of its floral characteristics. However, while the number of pappus bristles is up to 4 in the known species of the genus, it is 5 in R. baskilensis . This difference caused the genus description to expand ( Fig. 2 ).

The structure of achene and pappus in Rhanteriopsis baskilensis was examined in detail with the help of SEM images. However, since actual samples (not digital images) of other species of the genus were not accessible, comparisons could not be made. In R. baskilensis , mature achenes are about half the length of the pappus. The strigosehispid hairs at the apex of the achene are quite prominent and are about 1/3 of the length of the achene. Although the pappus bristles appear mostly equal in length, they can differ by 1/5−1/4 ( Fig. 3 ).

The achenes of Rhanteriopsis baskilensis are very sparsely woolly hairy, 4-edged and 4–6-ribbed. A carpopodium is observed at the base of the achene. The body consists of long prismatic cells. The strigose-hispid hairs at the achene apex are of different lengths, ± flat and the tips emarginated ( Figs. 4−5 ). Pappus bristles are clearly flat, with serrated margins directed towards the tip. The width of the middle of the bristle is 1/3 of the total bristle width ( Fig. 6 ). It can be assumed that flattening of the pappus bristles may facilitate its transport by wind, and the saw-like teeth may contribute to the transport of the achene by animals (by clinging to the body surface of the animal).

The genus Rhanteriopsis makes the first record for Turkey in present study. The other known species of the genus generally grow in arid and stony-rocky habitats. Rhanteriopsis microcephala and R. lanuginosa , which are distributed in Syria and Lebanon, are the closest species to R. baskilensis in terms of distance. Rhanteriopsis lanuginosa prefers altitudes of 900−1000 meters range in stony plains and slopes, sparsely grassy or shrubby habitats in Syria and Lebanon. Rhanteriopsis microcephala grows in rocky habitats at c. 1500 meters in Syria and shows more similarity to R. baskilensis in this preference. The areas where R. puberula and R. bombycina species grow are at greater distances than the areas where R. baskilensis grows. While R. puberula prefers calcareous, limestone or sandstone cliffs at altitudes of 350−2000 meters in the Zagros Mountains (within the borders of Iran and Iraq), R. bombycina prefers limestone cliffs at altitudes of 1000−1500 meters in the Zagros Mountains (only within the borders of Iran) ( Wiklund 1987) ( Fig. 7 ).

Distribution and conservation status

The population of Rhanteriopsis baskilensis is currently only observed in an area of approximately 2 km 2 in the northwest of Baskil (Elazığ province, Turkey), between İçlikaval and Þahindere villages. However, individuals belonging to the species are likely to grow in similar habitats observed in the nearby area. Approximately 300 individuals were counted in an area of 2 km 2 at the type locality of the species. The species grows in rocky areas and the probability of these areas being degraded to become agricultural areas is very low. On the other hand, intensive grazing by farm animals in and around the type locality of the species can be considered as a threat. Considering the type locality and similar habitats in its immediate vicinity, R. baskilensis grows in an area of less than 100 km 2. Considering the known range and potential threats together, it was found appropriate to recommend the Critically Endangered [CR: B1ab(i,iii)] threat category for the species ( IUCN Standards and Petitions Committee 2019).

Specimens examined

Rhanteriopsis baskilensis .— TURKEY. Elazığ: Baskil district, between İçlikaval and Şahindere villages, between 1500 and 1640 m a.s.l., rocky areas, 22.7.2021, L.Behçet 20517 (GAZI, Bingöl University Faculty of Arts and Sciences Herbarium) .

Figures

FIGURE 1. Habit of Rhanteriopsis baskilensis (holotype).

FIGURE 2. Rhanteriopsis baskilensis. A. capitulum, B. inside of capitulum, C. disc-floret, D. disc corolla and glandular lobes, E. style, F. paleae, G. achene and pappus, H. achene.

FIGURE 3. The achene and pappus of Rhanteriopsis baskilensis.

FIGURE 4. The achene of Rhanteriopsis baskilensis.

FIGURE 5. The achene detail of Rhanteriopsis baskilensis. A1−A2. base of achene, B1−B2. Body of achene, C1−C2. apex of pappus and strigose-hispid hairs.

FIGURE 6. The pappus bristles detail of Rhanteriopsis baskilensis. A. general view of 5 of pappus bristles, B. flattened pappus bristles, C. serrate margins of pappus bristles, D. body of pappus bristles.

FIGURE 7. Distribution of Rhanteriopsis baskilensis (), R. microcephala (), R. lanuginosa (), R. puberula () and R. bombycina (').