Berteroa physocarpa Yüzb. & Al-Shehbaz, 2017

Yüzbaşioğlu, Sirri, Al-Shehbaz, Ihsan A., Yüzbaşioğlu, Elif & Dalyan, Eda, 2017, Berteroa physocarpa (Brassicaceae), a new species from NW Turkey based on morphological and molecular data, Phytotaxa 305 (2), pp. 87-96 : 90-93

Berteroa physocarpa Yüzb. & Al-Shehbaz , sp. nov. ( Figs. 1 , 2 ).

Diagnosis:— Berteroa physocarpa is readily distinguished from all other congeners by a combination of perennial habit, strongly inflated fruit with glabrous valves, and white flowers.

Type:— TURKEY. A 2( A) Kocaeli. Kartepe, zirve çevresi, 1600 m, 24 July 1994, A. J. Byfield 1058 (holotype ISTE 67180!, isotype ISTE!).

Description: Herbs, perennial, moderately pubescent with appressed stellate trichomes. Stems 40–75 cm, ascending, terete, branched at base, leafy, pubescent with 5–7 unequal-rayed stellate trichomes longest rays of which parallel to stem long axis, some appearing as submalpighiaceous. Basal leaves rosulate, oblanceolate, 4–12 × 1–4 cm including basally flattened petioles 1.5–3 cm, pubescent with appressed, sessile stellate trichomes some with central subsetose ray and others submalpighiaceous along entire to coarsely dentate margin, base cuneate to attenuate; middle cauline leaves oblanceolate, lanceolate, to elliptic, 4.5–7 × 1–1.5 cm, sessile, cuneate at base, gradually reduced in size upwards and uppermost to 10 × 2.6 mm. Raceme densely flowered, only slightly elongated in fruit; rachis pubescent as stem; fruiting pedicels 6.5–9.4 mm, ascending to divaricate-ascending, straight or slightly curved, pubescent with stellate trichomes some with reduced rays except subsetose central ray and appearing simple. Sepals 3.7–4.5 mm, ovate-oblong, with membranous white margin, stellate pubescent, subapically with setose central ray and reduced lateral rays, subsaccate at base; petals white, 6.3–8.5 mm, narrowly obcordate, with oblong lobes 2.5–4 mm, attenuate to flattened claw-like base 3–4 mm; median filaments 4.1–4.9 mm, dilated at base, unappendaged; lateral filaments 3.3–4.1 mm, basally with toothed oblong appendage 0.7–0.9 mm; anthers yellow, oblong, 1–1.3 mm; nectar glands 4, toothlike, 1 on each side of lateral stamen; ovules 4–5 per locule. Fruit oblong-ellipsoid to globose, distinctly inflated, 9.3–13.3 × 6.8–8.6 mm, glabrous on valves, occasionally with a few trichomes along proximal part of replum; septum complete, membranous; style slender (2.6–)3–3.8(–4.2) mm, glabrous or with few trichomes at base. Seeds suborbicular-lenticular, strongly flattened, minutely reticulate, 3–4 mm diam., including undulate, usually paler wing 0.4–0.6 mm wide.

Distribution and habitat: Berteroa physocarpa grows in the alpine-subalpine zone and is known only from two isolated populations at high altitudes in NW Anatolia. The type locality is on the second highest peak (ca. 1600 m) in the Marmara region. The plants grow on limestone slopes around the peak at the edge of the forest boundary. Uludağ, the other distribution area, is the highest part of the region and reaches to 2543 m. Specimens were collected from Uludağ at about 2200 meters from Kuşaklıkaya by G. Güleryüz.

IUCN Red List category: The distance between the two localities of Berteroa physocarpa ( Fig. 3 ) is about 100 (air) kilometers. The species is quite localized and occupies only a limited area (ca. 0.2 km 2) in the type locality, Kartepe. It is represented by mature individuals not exceeding 50. The main threats affecting the small population are overgrazing, road construction, skiing, and tourism. We did not have a chance to study the Uludağ population. Conservation status of five species endemic to Uludağ was studied by Daşkın & Kaynak (2011). One such species is Gysophila olympica Boiss. (1849: 55) , and only it grows on Mt. Uludağ, Kuşaklıkaya, and its surroundings. According to these authors, Kuşaklıkaya and its surroundings have been used both for winter sports and recreational activities in summer. The principal threats there are the construction of ski runs and ski tracks and partial overgrazing. We believe that similar threats are applicable for this new species. According to available data, the conservation status of B. physocarpa is evaluated as Endangered [EN B2ab(i,ii,iv): area of occupancy less than 500 km 2, known at no more than 5 locations] ( IUCN, 2001).

Phenology: Flowering starts at the end of the July and continues until October. Mature fruits have been collected in August–October.

Etymology: The specific epithet refers to the inflated fruit.

Karyology: The chromosome number reported here for this new species is 2 n = 2 x = 16 =14sm + 2 sm-SAT (from type locality, SYZB 3829). The basic chromosome number x =8 is the same as that for other Berteroa species (see Warwick & Al-Shehbaz 2006 and BrassiBase). The chromosomes are small, 1.20–1.52 μm. A pair of SATchromosomes was observed in some of the chromosome sets ( Fig. 2d ). The same chromosome number and a pair of SAT-chromosomes were observed by Ančev & Goronova (1999) for Berteroa incana ( Linnaeus 1753: 650) de Candolle (1821b: 291) subsp. stricta (Boiss. & Heldr. in Boissier 1854: 35) Stojanoff & Stefanoff (1948: 533) from Bulgaria.

Phylogenetic analysis: The purpose of this molecular work was not to deal with family-wide or Alysseae-wide phylogenies. Rather, it was just to find out whether or not Berteroa physocarpa falls within the tribe Alysseae and the three genera that have either bifid ( Berteroa , Galitzkya Botschantzeva 1979: 1440 ) or deeply emarginate ( Aurinia Desvaux 1815: 162 ) petals. Recent studies on the tribe (e.g., Rešetnik et al. 2013, Španiel et al. 2015), as well as the Alysseae database (Alybase: www. alysseae .sav.sk), should be consulted for a wealth of information and literature on the tribe.

A total of 11 taxa (15 accessions), including the outgroup ( Table 1), were used. The result of multiple alignments of ITS region, including the 5.8 S rRNA gene, was 579 bp, of which 402 (69 %) were constant, and number of distinctsite patterns were 129. The G+C content of taxa within the ingroup was similar and averaged 55%. The maximum likelihood tree, which was constructed in Bayesian models, was TIM3e+G. Based on ITS DNA sequences, Berteroa was sister to Galitzkya and both to Aurinia the tribe Alysseae ( Fig. 4 ). The ITS data show that B. physocarpa (bootstrap value 48%) is hardly separated from B. orbiculata , but it clearly fell within the genus Berteroa ( Figs. 4 , 5 ).

Discussion: A brief account of the other Berteroa species in Turkey is presented here. Berteroa mutabilis ( Ventenat 1802: 85) de Candolle (1821b: 292) is a widespread and common species in Turkey, especially in NE Anatolia, along the valleys. It is also recorded from a few localities at the coastal edge of the Thrace in Marmara region.

Berteroa obliqua (Sm. in Sibthorp & Smith 1813: 12) de Candolle (1821b: 292), which was added to the Turkish flora by Davis et al. (1988), was collected from Tekirdağ, Mahyadağ by Hermann but our field and herbarium studies indicate that it is common in Thrace region.

Berteroa orbiculata de Candolle (1821b: 293) differs from the other Berteroa species by its pale yellow petals. Cullen (1965) indicated that it is known from Trabzon (NE Anatolia). However, based on our extensive fieldwork and herbarium studies, it apparently does not grow there. The species was reported by Sorger (1978) based on his collection in 1967 around Izmir, Bergama (voucher in LINZ herbarium) as the last known record of this species. Despite searching for it in that region many times, the species was not found.

According to Davis et al. (1988), Berteroa incana is only known from European part of Turkey in Thrace. The first collection from Tekirdağ was given as a doubtful record, and the second was from Çilingoz (İstanbul). Özbek et al. (2015) indicated that specimen collected from Çilingoz is B. obliqua , and that B. incana was reported from Kars as a new record for the flora of Turkey.

During our studies in Turkish herbaria, we found an interesting specimen at HUB that was collected from Isparta by H. Peşmen & A. Güner in 1974. Peşmen annotated it as Berteroa orbiculata in 1975 and later Peter H. Davis as B. mutabilis . We sampled the plants from that locality, and they clearly grow in undisturbed, natural habitats. The population is currently studied by us both morphologically and molecularly, and we believe that it represents an undescribed subspecies of B. orbiculata .

Figures

FIGURE 1. Berteroa physocarpa. a: plant. b: petal. c: short filament. d: long filament. e: fruit. f: seed. (Drawn by Al-Shehbaz from S. Yüzbaşıoğlu 3790 at MO)

FIGURE 2. Berteroa physocarpa. a: habit and habitat. b: flowers and fruits. c: rosette leaves. d: somatic chromosomes (arrow indicates satellite).

FIGURE 3. Distributional map of the species of Berteroa in Turkey. B. physocarpa (); B. mutabilis (); B. obliqua (); B. orbiculata (); B. incana ().

FIGURE 4. Maximum likelihood tree established under TIM3e+G model of DNA substitution in W-IQ-TREE in an analysis of 14 ITS sequences from 11 taxa. Ultrafast bootstrap values are indicated from 1000 replicates.

FIGURE 5. Pyhlogenetic position of Berteroa physocarpa in tool of BrassiBase using ITS sequence.