Stachys milasensis Ö.Güner, 2022

Güner, Özal, 2022, Stachys milasensis (Lamiaceae), a new species from Turkey, Phytotaxa 566 (1), pp. 64-72 : 66-70

Stachys milasensis Ö.Güner , sp. nov. ( Figs. 1a–b )

Diagnosis: — Stachys milasensis differs from the related S. swainsonii by having dense villous flowering stems, ovate to oblong-lanceolate cauline leaves, remote verticillasters, bilabiate calyx, oblong-ovate and spinescent-tipped calyx teeth and oblong-ovate nutlets.

Type: — Turkey, Muğla province, Milas distinct, beetwen Kayabükü and Çukur villages, above Konak village , metamorphic rocks slopes, 660 m, 10.05.2019 Ö.Güner 3101 (holotype GAZI; isotypes ANK, HUB) .

Description:—Suffrutescent perennial herbs. Flowering stems numerous 7–18(-35) cm long, erect to pendent, usually branched at base, densely villous with glandular papillate and sessile glands. Cauline leaves ovate to oblong-lanceolate, 7–18(-26) × 6–14 mm long, margin crenate, apex rounded to obtuse, truncate to attenuate at base; covered densely villous with glandular hairs; petiole 3–10 mm long, uppermost sessile. Floral leaves similar to cauline leaves but smaller, longer than verticillasters at below and gradually shorter than verticillasters toward, margin crenate, apex obtuse, sessile. Verticillasters 4–6 flowered, the lower subremote, the upper 2–3 approximate. Bracteoles few, oblonglanceolate or lanceolate, 2–3.5 mm long, shorter than 1/2 of the calyx, narrowly acute, cuneate-truncate at base, covered dansely villous. Pedicels 1–2 mm long. Calyx bilabiate, tubular to subcampanulate, 6–9 mm long, dansely villous with glandular papillate and sessile glands; teeth unequal, oblong-ovate with short spinescent tip, 2–3 mm long, 1/2–1/3 × tube; spin c. 1 mm long, glabrous. Corolla white, 13–15 mm long, lips streaked and spotted with pink inside, pilose hairy with glands outside; tube exserted from calyx, 7–9 mm long, annulate; limb bilabiate, upper lip 4–5 mm long, retuse the lower 3-lobed, middle lobe longer than 2 lateral lobes, 6–8 mm long, emerginate. Style 8–9 mm long, not exceeding the upper lip, apex equally bifid into subulate stigmas. Stamens 4, within corolla tube; anthers dithecous; thecae divaricate; filaments flattened and with short swollen hairs in point of attachment to corolla tube. Nutlets oblong-ovate, faintly trigonous, winged near base, blackish, 2.0–2.5 × 1.3–1.5 mm.

Phenology:— Stachys milasensis flowers from early May to the end of June. The ripe seeds are released from the end of May to the end of August.

Distribution and ecology:— Stachys milasensis grows in Beşparmak Mountain in the districts of Milas (Muğla) and Çine (Aydın) at an elevations from 600- 100 m ( Fig. 3 ). The region hosts endangered biota, various noticeable geomorphological formations and some ancient cities. The area contains rock units belonging to the Menderes Massif, Çine, and Southern Submassif, which consists of metamorphic rocks. These rocks exhibit high geomorphological features such as bald hills, domes, and pillars with a flat top, weathering pits, polygonal cracks, tafoni, honeycombs, corestones, blocks, spheroidal weathering, exfoliation structures and flared slopes ( Gül et al., 2019). Stachys milasensis is well adapted to live on open rock cracks in Pinus pinea L. (1753: 1000) forest in the region ( Fig. 4 ). The new species shares habitat with the herbs Allium sphaerocephalon L. (1753: 297), Sedum confertiflorum Boiss. (1843: 15) and Ziziphora taurica M.Bieb. (1808: 414) , and the shrubs/trees Cistus creticus L. (1762: 738), Lavandula stoechas L. (1753: 573), Olea europaea L. (1753: 18), Pinus pinea and Spartium junceum L. (1753: 708).

Etymology and vernacular name:—The epithet of the new species is derived from the name Milas district of Muğla where the type specimen was collected. The name of S. milasensis is proposed as “Milas Kayaçayı” in Turkish, according to the guidelines of Menemen et al. (2016).

Conservation status: — Stachys milasensis is known only from special geomorphological occurrences in Beşparmak Mountain in Turkey. The new species should be classified as CR (Critically Endangered) according to IUCN (2022) criteria. The estimated area of occupancy is less than 15 km 2 with the number of mature individuals being less than 300 [criterion B2ab (ii, iv, v); C2a (ii)]. In the region, the most prominent threat to the new species is habitat destruction through activities such as mining operations, harvest of pine nuts and overgrazing. In addition, more wildfires in Muğla have occurred in recent years. If the wildfires continue or spread to more areas in the province, the habitat of the new species may damage in the near future. Especially excessive grazing and wildfires are threats that are affirming themselves globally in temperate climate areas where administrations are trying to find remedies trought management targeted ( Wagensommer et al., 2017).

Taxonomic relationships: —Section Swainsoniana, which has distributed in a limited region and contains some local endemic species, is among the lesser known sections. Bhattacharjee (1980) described the section Swainsoniana and divided it into two subsection. This section comprises 11 species (13 taxa), many of which are endemic to Greece. The section, mostly distributed in the eastern Mediterranean region, is characterized by following characters: ovate to narrowly ovate-oblong or ovate-lanceolate lower cauline leaves, attenuate to truncate at base, rarely subcordate, verticillasters (4-)6(-10)-flowered usually with conspicuous herbaceous bracteoles, as long as calyx or slightly shorter, rarely few and setaceous, calyx ± bilabiate, subcampanulate to campanulate and teeth ± equal ( Bhattacharjee, 1980). The first subsection Swainsonianeae is distinguished by shorter flowering stems (5–16 cm long) and obovate leaves with attenuate bases and is only distributed in Greece. The other subsection Decumbentes is described by ovateoblong to ovate-lanceolate leaves with rounded to subcordate base and taller flowering stems (30–55 cm long) and grows in many parts of the Balkan Peninsula. Furthermore, based on phylogenetic analyses, Salmaki et al. (2019) described Swainsoniana R.Bhattacharjee [Y.Salmaki] as a new clade.

The subsection Swainsonianeae is confined to Greece and includes seven perennial suffruticose taxa of narrow distribution and particular habitat preference ( Constantinidis, 1995). In the subsection, Stachys swainsonii , closely related to the new species, is particularly polymorphic and has three subspecies which are all chasmophytes in Greece ( Dimopoulos et al., 2013). The new species Stachys milasensis belongs to the subsection and only grows in Turkey. It is characterized by having dense villous flowering stems and oblong-ovate calyx teeth with spinescent tip ( Figs 1a–b ). The newly described species is similar in appearance to S. swainsonii with a dwarf form of flowering stems, more cauline leaves and white corolla but differs in its dense villous flowering stems, ovate to oblong-lanceolate cauline leaves, remote verticillasters, oblong-ovate and spinescent-tipped calyx teeth and oblong-ovate nutlets ( Fig. 1 , Table 1 ).

The calyx is an important character used to distinguish Stachys species (Güner et al., 2021), and also the ratio of the tooth to calyx is the main diagnostic characteristic. While the new species has oblong-ovate calyx teeth, S. swainsonii has triangular to lanceolate teeth ( Fig. 2 ). Therefore, the distinctive characters of the new species such as dense villous small flowering stems and oblong-ovate calyx teeth with short spinescent tips are included in the section and the known boundaries of the section are expanded.

Stachys swainsonii is a Greek endemic with a narrow distribution and is restricted to Parnassos mountain in Greece ( Fig. 3 ). The species and S. milasensis are chasmophyte species in the same subsection. However, the new species is geographically isolated from S. swainsonii . The new species grows in southern Turkey, while S. swainsonii is only distributed in Greece ( Fig. 3 ). Stachys milasensis is well adapted to live in Besparmak Mountain which attracts attention with its cultural, natural, geological, historical and archaeological in western Turkey ( Fig. 4 ).

The new species Stachys milasensis has oblong-ovate calyx teeth which are not visible in other species in Turkey ( Figs. 2a , 5 ). The common types of calyx teeth in Turkey are lanceolate, lanceolate-subulate and triangular to triangularlanceolate. Moreover , cauline leaves of the new species are ovate to oblong-lanceolate. Also , the new species is the first member of the section to be represented in Turkey. Therefore , the section species grow in both Greece and Turkey. With this addition, the number of Turkish Stachys species amounts to 94 (121 taxa), and 65 (53.7%) of these taxa are endemic.

Additional specimens examined:— Stachys euboica Rech.f. : Greece, Insula Euboea meridionalis, 5 km. a promontorio Kaphireos meridiem versus in fissuris rupium calc. 22.06.1958, Rechinger, K.H., #19064 (K!). Stachys menthifolia Vis. : Croatia ( Croatia), Dalmatia, Visiani, R. 1832 (K!). Stachys milasensis (paratype): Turkey, Muğla province, Milas, between Kayabükü and Konak villages, rocks slopes, 28.06.2019, Ö.Güner 3102a (Herb. Ö.Güner); Stachys spruneri Boiss. : Greece, Corÿdalus, Spinner s.n. (K!). Stachys swainsonii (Lectotype) : Greece, Parnassus, Swanton, W., #64 (K!) .

Figures

FIGURE 1. Stachys milasensis, a—general view, b—cauline leaves and verticillasters. Stachys swainsonii, c—general view, d— verticillasters (photograph by. G. Pantakis).

FIGURE 2. Flowers of Stachys milasensis (a) and S. swainsonii (b) (photograph by. S. Giannakopoulou).

FIGURE 3. Geographical distribution of Stachys milasensis (★) and S. swainsonii (▲).

FIGURE 4. Habitat of Stachys milasensis in Muğla province, southwestern Turkey.

FIGURE 5. Stachys milasensis, a—dissected corolla and calyx, b—flower, c—cauline leaves.