Orobanche mlokosiewiczii Piwow., Ó. Sánchez & Moreno Mor., 2017
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publication ID |
https://doi.org/ 10.11646/phytotaxa.319.2.1 |
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persistent identifier |
https://treatment.plazi.org/id/8E2687C4-FFE6-FF94-A094-2006FA2EFA2B |
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treatment provided by |
Felipe |
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scientific name |
Orobanche mlokosiewiczii Piwow., Ó. Sánchez & Moreno Mor. |
| status |
sp. nov. |
Orobanche mlokosiewiczii Piwow., Ó. Sánchez & Moreno Mor. View in CoL , spec. nov. ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 )
Type: — GEORGIA. Mccheta-Mtianeti distr. : Dariali Gorge, near the village of Gveleti, moist tall herbaceous vegetation near waterfalls, N. E. exposure, ca 1,700 m, 18 July 2015, R. Piwowarczyk s.n. (holotype KTC!; isotype KRA!) .
Description: —Plant, (16–)30–40(–53) cm tall, whitish, pale white-yellow, pale yellow, pale dirty pink. Stem simple, slender (1.5–)2.0–2.5(–4.0) mm in diameter in the upper part, (3.0–)4.0–5.0(–6.0) mm in the middle, slightly widening towards the base, (3–)5–6(–7) mm; slightly bulbous at base; slightly striate (clearly striate when dry); densely glandular-pubescent in the upper part, with white glandular hairs 0.8–1.2 mm; stem pale white-yellow or pinkish-brown pale, rarely (pale brown or brown when dry). Basal leaves (8–)12–14(–19) mm × (3.0–)4.5–5(–7.0) mm, ovate-lanceolate (triangular) to lanceolate, glabrous abaxially, or shortly ciliate at the edge with hairs ca 0.8 mm. Upper leaves (12–)15– 17(–21) mm × (3.0–)4.5–5.0(–6.0) mm, narrowly lanceolate to lanceolate, becoming sparse above, more or less erect, pale yellow, pale brown, changing early to brown when drying, especially at the top; densely glandular-pubescent, with hairs 0.8–1.2 mm. Inflorescence (3.0–)7.5–9.0(–15) cm × (2.5–)3.0–3.5(–4.0) cm, cylindrical to slightly ovate, shorter than the remaining stem; (4–)10–12(–22)-flowered, ± dense (not very compact), sometimes lax. Bracteoles are absent. The flowers are erecto-patent.
Bracts (13–)16–17(–22) mm × (4–)5–6(–7) mm, shorter or equal to the corolla, narrowly lanceolate, with dense white or pale yellow glandular hairs, 0.4–0.7(–10) mm long, the same colour as leaves. Calyx (7–)9–10(–13) mm long, only (1.0–)1.5–2.5(–4.0) mm wide at the widest point, shorter than half of the corolla tube; two segments, free, clearly separate, simple, entire, narrow, with teeth long, acuminate almost filiform at apex and with bases gently ovate, pale yellow, pale pink, pale brown and become ± brown in large part when drying, nerves conspicuous in dry specimens and with dense glandular-hairy, hairs ca 0.5–0.8(–1.0) mm, white or pale yellow. Corolla (17–)20–23(–25) mm long, (7–)10–12(–14) mm in diameter in the central part; campanulate, rarely tubular-campanulate, with a very wide open throat (often the bottom of the corolla can be seen), usually strongly inflated above the insertion of the filaments, and strongly constricted below; the dorsal line slightly curved, in the upper part straight and strongly patent; externally glandular-pubescent with white or pale yellow (in dry form with orange glands) glandular hairs of (0.2–)0.4–0.8(–1.0) mm, more or less abundant, hair cover slightly denser at upper lip; corolla pale white-yellow, whitish, rarely whitishpink, yellowish-white, with dirty white, pale pink or pale brown veins, very sensitive to damage and browning; upper lip slightly emarginate, later distinctly curved up and patent, very rarely with two broad lobes, emarginated, sparsely glandular hairy also in the inner part, hairs ca (0.2–) 0.3–0.4 mm; lower lip with three oval, or ± rectangular to ± triangular lobes, central lobe larger than lateral lobes, lobes irregularly dentate on margins, lobes sparsely glandular hairy also in the inner part.
Stamens obliquely inserted, adaxial filaments 4–5 mm above the corolla base, and abaxial at (3.0–)3.5–4.0(–4.5) mm, slightly widened at base. Filaments (15–)16–17(–19) mm long, (1.0–)1.3–1.5(–2.0) mm wide, clearly geniculate, densely villous in the base to ± middle part; not glandular, white hairs (0.5–)0.8–1.0(–1.3) mm long, upper part with dense short, usually ca 0.1–0.2 mm, white with orange glands, glandular hairs; filaments white to pale yellow or pale pink. Anthers (3.0–)3.5(–4.0) mm long, ca 1.5 wide, oblongoid, mucronate, pale brown to brown (pale brown when dry); basally and along ¾ of suture distinctly and numerous hairy (ca 0.4–0.8 mm). Ovary 8–10 mm × 3–4(–5) mm, glabrous or with very sparse white glandular hairs ca 0.2 mm above, whitish, pale yellow, pale pink, basally clearly dirty yellow; lateral opening by two longitudinal slots. Style 12–15 mm long, with very sparse (more abundant, conspicuous and dense on the upper part) short glandular hairs, ca 0.2–0.3 mm long, style pale yellow to whitish and pale pink. Stigma bilobed, lobes elongated spherical to ovate and ± flattened, with and numerous warts (orange when dry) on the lobes and yellow or bright yellow. Seeds ovoid or oblongoid; seed coat reticulate with polygonal shallow cells, which range from more or less isodiametric or irregular to tangentially elongated; seed coat is pitted. Pollen inaperturate, spheroidal. The flowers emit a sweet-sickly scent.
Distribution and habitat: —The locality of the newly-described species is situated in the Kazbegi region in the central part of the Great Caucasus range, in Georgia, near the Russian border. So far, the species was found only at one locality and is probably endemic to the Greater Caucasus. The Dariali Gorge (or Caucasus Gates) is a steep cleft in the mountains, in the valley of the Tergi river, alongside which is a historically and strategically important road, also know as the Military Highway, connecting Russia and Georgia. Tectonically the area is included in the Greater Caucasus Mountain range zone. Lithologically it is represented by Jurassic and Paleozoic rocks—clay slate, slate, arkosic and tuffaceous sandstone, older granites, younger lava, quartzite, granitoids of Dariali and Gveleti granite massive. The Kazbegi region is of volcanic origin with characteristics of relief, i.e. the sharp ridges, steep and rugged peaks, caves, very deep gorges and canyons, often with impressive waterfalls in them. Not uncommon, there are also different sized glaciers and glacial deposits occurring in many places. The highest elevation of the region is 5033 m a.s.l.—Mt. Kazbegi ( Maruashvili 1971, Abdaladze et al. 2015).
In one of the branches of the Dariali Gorge, near the village of Gveleti, in a narrow and steep gorge with a waterfall, the locality of O. mlokosiewiczii was found. It grows on a shaded slope, N.E. exposure, near a waterfall within the coverage area of water splashing from it ( Fig. 3 View FIGURE 3 ). The plant community has been identified as thermo-hygrophilous subalpine tall herbaceous vegetation (Megaphorbia) ( Nakhutsrishvili 2013), dominated by Senecio propinquus , Aconitum cymbulatum , Heracleum cf. sosnowskyi , Filipendula ulmaria , often with ferns ( Dryopteris , Athyrium ) etc. Below the waterfall, where there was a stream, this community was dominated by Heracleum cf. sosnowskyi , Aconitum orientale , Cephalaria gigantea etc.
Phenology: —Flowering period July–August, fruiting in August.
Ecology: —Parasitic on Aconitum cymbulatum (Schmalh.) Lipsky in Lipsky (1899: 213) ( Ranunculaceae ), Caucasian endemic species ( Fig. 3 View FIGURE 3 ). The host species was before flowering, and it flowers were only in buds. The host connection has been confirmed by a soil outcrop.
Etymology: —The epithet ‘ mlokosiewiczii ’ honours Ludwik Młokosiewicz (1831–1909), a Polish explorer of the Caucasus, naturalist, botanist and zoologist. He also urged the protection of the forested area in N.E. Georgia, thereafter known as the Lagodekhi Protected Areas. More than sixty new flora and fauna species were discovered by Młokosiewicz with many of them named after him (after Chodubski 1982).
Conservation: —The known locality of Orobanche mlokosiewiczii lies in the protected areas of Kazbegi National Park. The new species does not seem to be seriously threatened because its habitats are relatively stable, away from settlements and destructive human activity. However, this gorge is popular with tourists, and the species is extremaly rare with a low number of individuals (less than 50). A threat may also be from mechanical destruction by the rapid flow of water from the waterfall, e.g. during rainstorms, as well as due to the subsequent change in habitat fertility. Moreover, in the Kazbegi region, Tertiary relict thermo-hygrophilous subalpine tall herbaceous vegetation is distinguished as the plant community most sensitive to fluctuations in temperature and humidity ( Abdaladze et al. 2015).
Phylogenetic analysis:— The analysis of the phylogenetic trees ( Fig. 4 View FIGURE 4 ) shows that both Orobanche krylowii Beck (1881: 309) and O. lycoctoni Rhiner (1892: 133) are grouped in two separated branches with bootstrap support over 60 and Bayesian posterior probability over 0.9. Orobanche mlokosiewiczii falls within an unresolved polytomy with these two species, but seems to be seperated from them. Indeed, analysis of sequences shows that O. krylowii (except one) differ from O. lycoctoni by 3 substitutions and 1 indel. O. mlokosiewiczii have 2 of these substitutions common with O. lycoctoni and one substitution and one indel is shared with O. krylowii . Also in the sequence of O. mlokosiewiczii is found one unique indel.
Discussion:— The Orobanche parasitise on the roots of plants in various families of flowering plants, especially Asteraceae , Fabaceae , Lamiaceae and Apiaceae . However, in the literature there are only a few true mentions of the parasite on species of Ranunculaceae , comprising only three species: O. lycoctoni on Aconitum Linnaeus (1753: 532) ( Carlón et al. 2002, 2005, 2008, Schneeweiss et al. 2009), O. haenseleri Reuter in Candolle (1847: 22) mainly on Helleborus Linnaeus (1753: 557) , and also species from Lamiaceae ( Carlón et al. 2005, 2008), and O. krylowii on Thalictrum Linnaeus (1753: 545) ( Frajman et al. 2013). So far, for the Orobanche parasite on Aconitum (exlusively A. lycoctonum Linnaeus (1753: 532)) only one species, O. lycoctoni , is known, occurring disjunctive on the Cantabrian Mts. in Spain and then in the Alps ( Schneeweiss et al. 2009, Sánchez Pedraja et al. 2016). The newly-described species, O. mlokosiewiczii , is the second, but it is a parasite of another species of Aconitum , A. cymbulatum , and was found in the Greater Caucasus in Georgia, almost 2,500 kilometers in a straight line from the nearest localities of O. lycoctoni in the Julian Alps in Slovenia.
Orobanche mlokosiewiczii clearly differs from other similar Orobanche species —especially by its mainly campanulate flowers and usually very wide open throat of corolla. Moreover, in place of insertion filaments, the corolla is initially highly inflated, bellied, and then narrowed sharply to the base. In addition to the above features, it differs mainly from O. lycoctoni and O. krylowii with free, definitely smaller and single calyx segments (in O. krylowii segments are also single, but are wider), smaller bracts, the dorsal line of the corolla and their not bilobed upper lip, higher filaments insertion, style with more abundant and conspicuous hairs, with flattened lobes but not disc-like stigma, and another species of host ( Fig. 1 View FIGURE 1 , Table 2).
In the local Caucasian context, the newly-described species is easily distinguished by its white, or white-yellow colour, specific mountains habitats and by its endemic host. Despite these characteristics, it also needs comparison with two somewhat similar and poorly known Greater Caucasus Mountains species, O. inulae Novopokrovsky & Abramov in Novopokrovsky (1950: 323) parasite Inula Linnaeus (1753: 881) , and the recently described O. flava subsp. cicerbitae Uhlich & Rätzel (2004: 207) [≡ O. cicerbitae (Uhlich et Ratzel) Tzvelev in Tzvelev (2015: 210)] parasite Cicerbita Wallroth (1822: 433) and Senecio propinquus Schischk. (1953: 406) . Regarding the last species, on the basis of the diagnosis and available photographs ( Uhlich 2015; Rätzel et al. 2016), it appears that this taxon is not related to O. flava Martius ex F.G. Schultz (1829: 9) as Tzvelev (2015: 210) seems to indicate, and its position and host are unclear. However, it is a very interesting and poorly known taxon, probably closer to the comparable species analysed in this work. A similar situation existed with O. lycoctoni , which was included as closely related to O. flava ; however, molecular data showed that it is not closely related, even with the other species of “grex” Curvatae Beck in Engler (1930: 243) [≡ O. “tribus” Curvatae Beck (1890: 34)] ( Manen et al. 2004, Carlón et al. 2005, 2008). While O. lycoctoni and O. krylowii , except O. haensleri , seem to be closely related, the relationship of this clade to other Orobanche remains unclear ( Schneeweiss et al. 2009, Frajman et al. 2013).
The differences between these five mountains species, with their striking whitish-yellow colour, always almost whitish, perhaps with the exception of the O. flava subsp. cicerbitae ( Rätzel et al. 2016) , are summarised below (Identification key, Table 2), following Novopokrovsky & Tzvelev (1958), Carlón et al. (2002, 2005, 2008), Rätzel & Uhlich (2004), Frajman et al. (2013), Uhlich (2015), Rätzel et al. (2016), and the authors’ own studies in herbaria and in the field.
Our molecular phylogenetic analysis supports that the taxon identified as O. mlokosiewiczii can be regarded as a new species, separated from O. krylowii and O. lycoctoni ( Fig. 4 View FIGURE 4 ). It seems to be roughly equally distant to both these species. Moreover, in analysing differences between O. krylowii and O. lycoctoni , we found that features shared by one of these species and O. mlokosiewiczii are also found in most of the rest of the taxa studied, indicating that these features are ancestral ones. Also, O. mlokosiewiczii has one indel not found in the other two taxons. Such results suggest that these three taxons are relatively young, diverging at a similar time, and evolving independently since then.
The newly-described species is, habitually, a close relative to series Orobanche sensu Teryokhin in Teryokhin et al. (1993: 39). However, the group of species included here is in the opinion of the authors arbitrary, the species contained in it are highly polymorphic and require future research. Of special interest are some morphological characteristics, different from other sections, e.g. Orobanche krylowii and O. lycoctoni have a uniquely enlarged, flattened (disc-like) yellow stigma. In O. mlokosiewiczii strange flattened lobes (but not disc-like) of the stigma were also encountered, but a more typical stigma was also observed in the species population ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 , Table 2). Noteworthy in the three above-metioned species is the characteristic ± strong narrowing of the corolla in place of insertion of the filaments. Accordingly, the three species appear to form a new series ( Orobanche series Krylowianae ser. nov.), which we propose inside the Orobanche sect. Orobanche L. (1753: 632), supported by morphological and ecological (Table 2), as well as phylogenetic results ( Fig. 4 View FIGURE 4 ).
Mountain habitats, through orographic, geographical and ecological isolation of some plant communities, have resulted in a high degree of local endemism.The Kazbegi region is characterised by rich flora and a richness of Caucasus endemic species (26%) and genera (6 out of 11) and a high diversity of plant communities ( Nakhutsrishvili et al. 2006, Nakhutsrishvili 2013, Abdaladze et al. 2015). Most species of Orobanche grow in highly insolated places, mainly in arid and semi-arid grasslands. Orobanche in the high mountain habitats of Europe and Asia still hold many puzzles to solve, both in their own local context, as well as in their global phytogeographic and evolutionary interrelationships.
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