Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich, 2021

Rätzel, Stefan, Hand, Ralf, Christodoulou, Charalambos S. & Uhlich, Holger, 2021, Phelipanche chionistrae (Orobanchaceae): a new holoparasitic species from Cyprus, Candollea 76 (1), pp. 77-82 : 78-80

Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich , sp. nov. ( Fig. 1 , 2 ).

Holotypus: CYPRUS. Distr. Lemesos: Troodos, by forest road to Kakopetria not far away from turn-off from Prodromos road, 1795 m, 34°56'29"N 32°51'55"E, 16.VI.2018, Hand 9011 ( B [ B 10 1067919 ]! image available at https:// herbarium.bgbm.org/object/B101067919) .

Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich is similar to P. olbiensis (Coss.) Carlón and P. rosmarina (Beck) Banfi s.l. but differs by its calyx teeth shorter than the calyx tube to equally long. Phelipanche chionistrae further differs from P. olbiensis by the longer indumentum of corolla and corolla lobes, by the mostly shorter corolla, by the elongated, longer and more hairy anthers and by the different host spectrum. Phelipanche chionistrae differs from P. rosmarina s.l. by the shorter indumentum of the stem, bracts, and calyx, by the shorter corolla, by the longer and more hairy anthers, by the strict specialization on serpentine substrate and by the different host spectrum.

Plant (5.5–)6.5– 8(–12) cm tall, intensely coloured in all parts (except throat bulges). Stem gracile, c. 1.2–3(–4.5) mm in diam., simple (very rarely with few branches), sparsely scaly, blackish-dark red to brownish-violet, turning pale brown lower down and dark brown higher up in dried stage, densely light glandular hairy; glandular hairs 0.1 –0.2 mm long, with yellowish glands. Scales sparse, 5–7(–8) mm long, colouration as in stem, dark brown in dried stage, glandular hairy, glabrous at the base, the lower ones broadly ovate, obtuse to triangular-acuminate, the upper ones narrowly triangularacuminate, apically sometimes ± cucullate. Spike few-flowered, with (3–)5–10(–12) flowers, 2– 5 cm × c. 2 cm wide, usually ± dense and distinctly shorter than the remaining stem. Bracts 5–7 × 3–4 mm, same colour as the stem, dark brown in dried stage, broadly based triangular-acuminate, whitish glandular hairy (hairs 0.1– 0.2 mm long), indistinctly multi-veined, shorter than the calyx teeth, reaching as far as the constriction of the corolla. Bracteoles lanceolate, 4– 5 × 1 – 1.4 mm, same colour as the stem, dark brown in dried stage, somewhat shorter than the calyx teeth, with short light glandular hairs. Calyx 4-toothed, relatively robust, 6–7 mm long; teeth broadly based narrowly triangular-acuminate, shorter than the calyx tube (rarely lanceolate and about as long as the calyx tube), reaching somewhat beyond the point of insertion of the stamens, same colour as the stem and the bracts, densely light glandular hairy; hairs 0.1–0.2 mm long. Corolla (9–)10–13(–15) mm long, erecto-patent, narrowly tubular, slightly curved above the constriction, whitish base largely hidden in the calyx tube, otherwise intensely dark purplish-violet (blackish purple in the budding state), veins indistinctly darker, externally with numerous light glandular hairs; hairs 0.1‒0.25 mm long. Upper lip 2-lobed; lobes rectangular, vertically erect or slightly recurved, with whitish, eglandular, multicellular hairs outside and apically inside, densely hairy on the margins; hairs 0.2‒0.35 mm long. Lower lip 3-lobed; lobes approx. equal, rounded to rarely slightly acuminate, antrorse or ligulate in the distal half, somewhat recurved downwards; indumentum as in upper lip. Throat bulges white, with antrorse to erect hairs. Filaments inserted 3‒3.5 mm above the base of the corolla tube, whitish hairy at the lowest quarter, otherwise glabrous; hairs 0.2‒0.4 mm long. Anthers white, oblong, 1.1‒1.4 × 0.8‒0.9 mm, apically ± acuminate, with up to 0.4 mm long curly hairs at base and suture. Ovary ovate, apically narrowed to the style base. Style hyaline glandular hairy, densely hairy below stigma; hairs c. 0.1 mm long. Stigma 2-lobed, ± light yellow. Seeds dark brown, variously shaped, most often ovate, but also rounded or polygonal, c. 0.2 × 0.4 mm.

Etymology. – The epithet chionistrae refers to the Mt. Chionistra, colloquially also known as Mt. Olympos, reaching 1.952 m above sea level and forming the highest elevation of both the Troodos range and the island of Cyprus.

Distribution and habitat. – Phelipanche chionistrae seems to be endemic to the highest altitudes of Mt. Chionistra ( Fig. 3 ). MEIKLE (1985) does not cite any material from the higher altitudes of Mt. Chionistra under the name Orobanche ramosa s.l. possibly because of its relative rareness. The summit consists of Upper Cretaceous, more or less serpentinized and tectonized harzburgites which belong to the Troodos ophiolite complex ( GSD, 1995). The vegetation of the peak is generally dominated by very open stands of Pinus nigra subsp. pallasiana (D. Don) Holmboe. Phelipanche chionistrae has been found on large openings with sparse vegetation cover, often less than 10 %. The terrain is extremely rocky complicating the determination of hosts of the new taxon, which sometimes grows in clefts of bare serpentine rocks at considerable distance from any other vascular plant. Hitherto, it has only been found at an altitude of 1500–1900 m.

Phenology. – Flowering individuals of P. chionistrae have been found from May to June.

Conservation status. – Phelipanche chionistrae was first observed in 2009 and since then several small populations (1–20 plants) have been located at eight places on the higher parts of Mt. Chionistra in an area of 10 km ², all found within the Troodos National Forest Park, which is also a Natura 2000 site, with controlled human activities. However, climate change is a potential threat for this high-altitude species. Considering the protected status of its distribution area, the low level of threat, the small known population (<1000) and the restricted Area of Occupancy (<10 km ²) ( IUCN, 2012) as well as incalculable habitat changes as a result of climate change (e.g., GIANNAKOPOULOS et al., 2010; HADJINICOLAOU et al., 2011), the species could be preliminary assessed as “Near threatened” [NT]. Further surveys are needed in the higher peaks of central Troodos such as neighbouring Madari and Papoutsa peaks to better understand its distribution.

Notes. – Phelipanche chionistrae parasitizes Alyssum troodi Boiss. (Brassicaceae) , most probably Teucrium cyprium Boiss. ( Lamiaceae ; Fig. 1C ) and possibly Alyssum cypricum Nyár. and Hypericum confertum subsp. stenobotrys (Boiss.) Holmboe (Hypericaceae) but does definitely not parasitize Rosmarinus officinalis L. ( Lamiaceae ).

Current opinion is divided as regards the taxonomy of species that obligately parasitize Rosmarinus officinalis L. We treat here these species as a complex including Phelipanche rosmarina (Beck) Banfi et al. s.str., Orobanche mariana A. Pujadas , Phelipanche pseudorosmarina (A. Pujadas & Muñoz Garm.) Uhlich and Orobanche rumseyana A. Pujadas & P. Fraga. This complex may represent different species and does not necessarily mean a definite synonymisation advocated by SÁNCHEZ-PEDRAJA et al. (2020). Phelipanche chionistrae is morphologically closely related to Phelipanche olbiensis (Coss.) Carlón et al. and the Phelipanche rosmarina complex. Morphological comparison can be found in Table 1 . Several diagnostic characters are lost in herbarium specimens of Orobanchaceae and they need to be studied in fresh material. This is the case for example of the indumentum in P. olbiensis which provides a good diagnostic character ( Table 1 ). Its flowering shoots are densely covered with short glandular hairs with relatively large yellow-hyaline heads; longer glandular hairs are scarce or lacking. Depending on the light conditions, plants look matt velvety or glittering ( Fig. 4A ). As it contrasts with the colour of the stem and bracts this character can be clearly seen. All other taxa have a rather silky indumentum ( Fig. 4B ) which is caused by a mixture of short and long glandular hairs with smaller, inconspicuous glandular head that cover stem and bracts.

Phelipanche chionistrae also differs by its preference for higher altitudes. With the exception of P. sinaica (Beck) Rätzel & Uhlich which however shows a differing host spectrum, the other taxa prefer lower altitudes (sea-level up to c. 650 m). Phelipanche sinaica differs from P. chionistrae by its permanently compact inflorescences which are relatively rich in flowers (c. (8‒)14‒28(‒30) vs. c. 3‒10(‒12)) and by its paler to dull violet corollae. Phelipanche sinaica parasitizes Lactuca viminea (L.) J. Presl & C. Presl and it is known to occur in Azerbaijan, Egypt and Iran ( RÄTZEL et al., 2017b). Apart from P. nowackiana (Markgr.) Soják , a NE Mediterranean species that also parasitizes perennial taxa of Alyssum s.l., Phelipanche chionistrae is the second species known to be a strict serpentinophyte.

Additional specimens examined. ‒ CYPRUS. Distr. Lemesos: Chionistra, near giant Pinus nigra tree, 1850 m, 12.VI.2009, Christodoulou s.n. ( B); ibid. loco, on S slopes of massif, 1735 m, 34°55'08"N 32°51'31"E, 22.V.2013, Hand & Christodoulou 6104 ( B); ibid. loco, 1825 m, 34°55'59"N 32°52'26"E, 30.V.2013, Christodoulou s.n. ( B). Distr. Lefkosia: Troodos, on forest road to Kakopetria, towards N Shoulder, close to seismological station on top E of forest road, 1828 m, 34°56' 49"N 32°51'38"E, 16.VI.2018, Hand 9013 ( B); 300 m S of Kannoures spring, 1550 m, 34°56' 26"N 032°52'47"E, 24.VI.2019, Hadjikyriakou 7754 (Herb. Hadjikyriakou); Kannoures spring , 1500 m, 34°56'36"N 32°52'45"E, 18.VII.2019, Hadjikyriakou 7762 (Herb. Hadjikyriakou) .

Figures

Fig. 1. – Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich in Mt Chionistra.A. Single plant habit; B. Inflorescence; C. Habitat, plants in Teucrium cyprium Boiss. [Photos: C.S. Christodoulou]

Fig. 2. – Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich. A. Flower, side view; B. Flower, front view; C. Anther; D. Calyx and bracteoles; E. Bract, outside; F. Stem scale, outside; G. Corolla, open, inside with stamens; H. Stigma and upper part of the style; I. Ovary with style and stigma. [Drawings: S. Rätzel]

Fig. 3. – Distribution map of Phelipanche chionistrae Rätzel, Hand, Christodoulou & Uhlich in Cyprus and in the central Troodos range (inlay). Elevation is represented in levels of grey.Phytogeographical divisions follow MEIKLE (1985).[Map: A.Antoniou & K. Papasavvas]

Fig. 4. – A. Phelipanche olbiensis (Coss.) Carlón et al. on Helichrysum L. in Crete, Greece;B. Phelipanche rosmarina (Beck) Banfi et al., Serra dos Candeeiros in Portugal. [Photos: A: A. Jagel & T.Schmitt; B: P. Pinho]