Petrorhagia dubia subsp. mustafanus Oskay

Oskay, Dilek, 2024, Petrorhagia dubia subsp. mustafanus (Caryophyllaceae), a new subspecies from Turkey, Phytotaxa 646 (1), pp. 75-81 : 76-79

Petrorhagia dubia subsp. mustafanus Oskay subsp. nov. ( Fig. 1 , 2 )

Type: — TURKEY, Manisa: Soma district, Dede mountain peak, 900 m, 39°18’26.90”N 27°46’42.19”E, 08 June 2023, Oskay 2944 (holotype EGE43791 !; isotypes: EGE, CBÜ —Department of Biology) .

Diagnosis:— Petrorhagia dubia subsp. mustafanus can be distinguished easily from P. dubia subsp. dubia by its petal colour (white and concolour veins vs. pink or purplish, with darker veins). Other important differences are the stem leaves length (10–20 mm vs. 20–60 mm), the lenght of bracts (14–17 mm vs. 6–14 mm), the lenght of capsule (8–9 mm vs 5–7 mm), and the diameter of seeds (0.8–1.0 mm vs 0.7–0.8 mm).

Description:— Annual, stems almost erect, simple or slightly branched, 20–75 cm long, glandular-tomentose at the middle internodes, glabrous above and below. Basal leaves 10–20 × 2–5 mm, narrowly oblanceolate. Stem leaves to 20–55 × 0.5–2.0 mm, narrowly lanceolate, linear, oblong, 5–8 veined (mostly 7) at the base, 3–5 veined (mostly 5) at the middle and 1 veined towards the apex. Leaves smooth margins. Stem leaves gradually become shorter from bottom to top, and the membranous width at leaf margins increases and is reduced almost to the bract. Leaf sheath 4.0– 7.5 mm long, at least twice as long as wide. Inflorescence capitate surrounded by 4(–6) largest bracts. Also, each flower surrounded by 2 narrower bracts. Bracts acute, mucronate brownish–scarious. The largest bracts 14–17 × 6–14 mm. Pedicels up to 3 mm. Calyx 10–14 mm, cylindrical, ribs 3 veined, teeth oblong, obtus. Petals 12–17 mm long, limb 4–5 × 2–3 mm wide, obcordate to bifid, white. The capsule is 8–9 mm long, ovoid. Seeds conical-papillate, 1.3–1.5 × 0.8–1.0 mm, strongly cymbiform (almost subglobose on the outer surface), with thick curved margin.

Etymology: —The name of the new subspecies is dedicated to my husband, “Prof. Dr. Mustafa Oskay”, who is a microbiologist and has always supported me throughout my academic life. Also, the name “Seçkin zarkaranfili” has been suggested as the Turkish name for the new subspecies since the name Mustafa in Turkish means the chosen one.

Flowering time: June.

Distribution and Ecological notes:— Petrorhagia dubia subsp. mustafanus were collected only above the tree line of Dede mountain of Soma district, Manisa province, West Anatolia ( Fig. 3 ). As a result of observations in the field P. dubia subsp. mustafanus has a local distribution subalpine zone of the mountain. In the fields of the new subspecies distribution areas, there are the characteristic mountain steppe plants, more wind resistant and cushion form plants such as Astragalus angustifolius Lamarck (1783: 321) , Dianthus anatolicus Boissier (1843: 22) ., Erodium somanum H.Peşmen (1968: 268) , Cerastium banaticum (Rochel) Steud (1841: 328) , Chamaecytisus eriocarpus (Boissier 1843: 10) Rothm (1944: 144) ., Aubrieta deltoidea (Linnaeus 1763: 908) DC (1821: 294) .

Conservational status:— It is known only Dede Mountain, one locality of the Soma district. The area of occupancy (AOO) of the subspecies is less than 10 km 2 and population density seems to be not very low. The new subspecies has been proposed as ‘Critically Endangered’ CR B2ab(i)(ii) according to the IUCN Red List categories and criteria ( IUCN 2022).

Taxonomic relationships:— Although Petrorhagia dubia subsp. mustafanus shows close similarities to P. dubia subsp. dubia , differ from each other in many aspects. Morphological differences are summarized in Table 1. P . dubia subsp. mustafanus can be distinguished easily from P. dubia subsp. dubia by the petal colour white and concolour veins in P. dubia subsp. mustafanus while pink or purplish, with darker veins in P. dubia subsp. dubia . Another important difference is the basal leaves length, 10–20 mm in P. dubia subsp. mustafanus while 20–60 mm P. dubia subsp. dubia .

Again, the largest bract lengths are significantly different in the two subspecies, 14–17 mm in P. dubia subsp. mustafanus , 6–14 mm in P. dubia subsp. dubia . Another difference is the capsule length, 8–9 mm in P. dubia subsp. mustafanus , 5–7 mm in P. dubia subsp. dubia . Seeds diameter 0.8–1.0 mm in P. dubia subsp. mustafanus , 0.7–0.8 mm in P. dubia subsp. dubia ( Fig. 4 ). The stem, calyx and petal lengths are also longer in P. dubia subsp. mustafanus .

Figures

FIGURE 1. Habit of Petrorhagia dubia subsp. mustafanus.

FIGURE 2. Herbarium specimen of Petrorhagia dubia subsp. mustafanus.

FIGURE 3. Distribution map of Petrorhagia dubia subsp. mustafanus () and P. dubia subsp. dubia () in Turkey.

FIGURE 4. Overview of fruit capsules and seeds of the related subspecies. a: Petrorhagia dubia subsp. mustafanus; b: Petrorhagia dubia subsp. dubia.