Semenovia zhobica N.Khan, A.Sultan & Lyskov, 2025

Khan, Nazar, Lyskov, Dmitry, Sultan, Amir, Ukrainskaja, Uliana, Samigullin, Tahir, Khan, Tahir, Ishaq, Kamran & Khan, Amjad, 2025, Semenovia zhobica (Apiaceae), a new species from Northern Balochistan, Pakistan, Phytotaxa 695 (1), pp. 91-104 : 95-97

Semenovia zhobica N.Khan, A.Sultan & Lyskov , sp. nova ( Figs. 2–4 )

Type: — PAKISTAN. Balochistan, Zhob District, Cheena Mountain, 31°26′0′′N, 69°15′04′′E, 1977 m, 09 July 2023, Nazar Khan (holotype RAW barcode RAW 103023).

Diagnosis: — Semenovia zhobica is most similar to S. glabrior but differs in its leaves (up to 45 cm long, tripinnate vs. 10–20 cm long, pinnate), leaf segments (linear–lanceolate to ovate, cuneate, sessile, bifid to trifid and ternate, puberulous vs. cuneate, tripartite, glabrous), umbel rays (2–3, 0.4–1.5 cm long vs. 6–10, 2–3 cm long), number of bracts (2–3 vs. 5), number of bracteoles (4–5 linear–lanceolate vs. 5–8 linear), shape of petals (ovate vs. obovate), and shape of mericarps (obovate–oblong, 5.5–6.2 mm long, puberulous on both surfaces vs. oblong, 5–6 mm long, minutely pubescent).

The new species is also close to S. suffruticosa , however, they differ in terms of plant height (60–110 cm vs. 45–70 cm), leaves (tripinnate, with leaf segments linear, lanceolate to ovate, sessile, ternate to bifid and trifid vs. pinnate, leaf segments, obovate, orbicular to triangular), number and length of rays (2–3, 0.4–1.5 cm vs. 7–10, 4–5 cm), number and shape of bracts (2–3, linear vs. 5–8, linear) and bracteoles (4–5, linear–lanceolate vs. 5–8, linear), and number of flowers per umbellet (3–5 vs. 12–15).

Compared to S. zhobica , the other endemic to Balochistan, S. heracleifolia differs in stem indumentum (pubescent and striate stem vs. glabrous and smooth), leaves (15–45 cm long, tripinnate with 3–4 pairs of pinnae, linear–lanceolate to ovate leaf segments vs. basal leaves 10–20 cm long, bipinnate, with 7 pairs of pinnae, leaf segments oblong– lanceolate), rays (2–3, 0.4–1.5 cm long vs. rays 2–6, 2–3 cm long), petal (ovate vs. orbicular to oval), mericarps size and shape (obovate to oblong 5.5–6.2 × 3–4 mm vs. obovoid 6 × 4.5 mm), and carphophore (bifurcated for 3/4 the length of mericarp vs. bifurcated to the base of mericarp).

Description: —Polycarpic, greyish–green puberulent perennial 60–110 cm tall with a vertical rootstock and much-branched caudex covered with rigid straw-like brownish remains of petioles and dead branches. Rootstock long, cylindric, 1–2.5 cm thick. Stems many from base, solid, 3–4 mm in diameter at base, intricately branched, striate, puberulent with small soft white hairs. Leaves mostly basal, basal leaves 15–45 cm long, puberulent–pubescent, coriaceous, petiole 6–18.5 cm long, terete, without adaxial groove, sulcate, solid, sparsely hairy to glabrescent, petiole vascular bundles marginal and central, lamina 10–26 × 5–10.5 cm, tripinnate, pinnae 3–4 pairs, leaf segments, 2–10 × 0.8–1.2 (–2) mm, linear, lanceolate, sometimes ovate, sessile, puberulous on both surfaces, terminal leaf segment sometimes undivided and up to 1.2–2.9 cm. Leaf sheath ovate, 3–6 × 3–6 mm, densely white tomentose. Lower cauline leaves similar to basal leaves, middle and upper cauline leaves few and gradually reduced, 1–11 cm long, ternate to linear. Compound umbels borne in long panicles, 5–24 cm long, striate, pubescent, rays unequal, 2–3, densely pubescent, 0.4–1.5 cm long, involucral bracts 2–3, lanceolate to ovate, 1–3 veined, densely white pubescent, 1.5–3 mm long, umbellets 3–5 flowered, involucel of 4–5 linear–lanceolate, densely pubescent bractlets, 1–2 mm long, pedicel densely pubescent, slender, 1–5 mm long. Calyx teeth, minute, densely white tomentose, c. 0.5 mm, triangular. Petals ovate, 1–1.2 × ca. 1 mm, yellow when young and yellowish green with a purplish–black centre and white margined when mature, tips inflexed, densely pubescent on the abaxial surface. Stylopodium short conic, wavy at the margin, yellow, turning brown when dry, 0.4–0.5 × 0.8–1 mm. Filaments yellow, unequal, 1–1.5 mm long, anther 0.3–0.5 mm yellow, style slender, 0.5–1 mm long, reflexed, yellow, glabrous, ovary c. 0.5 mm, white tomentose. Fruits with a slender carphophore, bifurcate 3/4 the length of mericarp; mericarp obovate–oblong, dorsally compressed, 5.5–6.2 × 3–4 mm, finely puberulous on both the surfaces. Dorsal ribs filiform, marginal ribs broadly winged, 0.5–0.8 (–1) mm broad. Vittae filiform, vallecular vittae solitary, 3/4 the length of mericarp, commissural vittae binate.

Morphology of surface of leaves: Adaxial surface: The shape of epidermal cell is more or less hexagonal with sinuate to undulate or with sinuate U- or V-shaped anticlinal walls pattern; the epidermal cell length is 69.71±0.21 μm and width is 47.98±0.09 μm. Stomata are of anomotetracytic type, more or less oblong; the length of the stomata is 27.49±0.07 μm and width is 17.91±0.11 μm. The length of stomatal pore is 24.29±0.63 μm and width is 9.57±0.04 μm. The length of the guard cell is 29.17±0.21 μm and width is 20.41±0.78 μm. The length of the subsidiary cell is 39.33±0.78 μm and the width is 21.83±0.69 μm; total stomatal index is 27.55%.

Abaxial surface: The shape of epidermal cell is more or less hexagonal to heptagonal or sometimes irregular with deeply sinuate U-shaped or undulate anticlinal walls patterns; the epidermal cell length is 73.23±0.09 μm and width is 52.36±0.16 μm. Stomata are of anomocytic or anomotetracytic type and its shape is oblong to elliptic; the length of the stomata is 25.79±0.11 μm and width is 15.99±0.41 μm. The length of stomatal pore is 27.11±0.05 μm and the width is 11.27±0.13 μm. The length of the guard cell is 26.43±0.66 μm and width is 22.11±0.08 μm. The length of the subsidiary cell is 37.49±0.10 μm and the width is 23.21±0.03 μm; total stomatal index is 19.25%.

Etymology: —The epithet refers to the type locality i.e., Zhob district in Balochistan, Pakistan.

Phenology: —Flowering from June to October; fruiting in September to October.

Distribution and ecology: —The new species grows on the western rocky slopes on gravelly soils, amongst boulders and rocks, in Cheena Ghar of Zhob District and the Tor Ghar Sulaiman range of Musakhail District in Northern Balochistan, Pakistan ( Fig. 7 ). Both localities, especially Cheena Ghar, have a very diverse flora, with elevations ranging from 1800 to 2380 meters. The new species grows in association with Spiraea brahuica , Sophora mollis , Zhobia glabra , Scutellaria petiolata , Sageretia thea , Rhamnus pentapomica , Pistacia khinjuk , P. atlantica , Minuartia meyeri , Lappula microcarpa , Isodon rugosus , Farsetia heliophila , Ephedra intermedia , Crucihimalaya wallichii , Cotoneaster persicus , Caragana ambigua , Buddleja crispa , Ajania fruticulosa , Xylanthemum macropodum , Pentanema persicum , Tulipa clusiana , Androsace rotundifolia , Allium sulaimanicum , grasses and mosses.

International Union for Conservation of Nature (IUCN) red list category: — Semenovia zhobica is known only from the Cheena Mountain (Zhob distict) and Tor Ghar (31°17′45′′N 70°01′25′′E, 2381 m, Musakhail district). The new species is rare and restricted to the mountains, usually growing on rocky slopes. Continuing decline is projected in light of a possible reduction in the area of occupancy, and the number of mature individuals has been subject to overgrazing pressure and extensive land sliding (Criteria CR B1a,b, B2a,b). The population of the new species is very limited, and adverse effects in its area of occupancy are leading to the reduction in the number of plants. The number of flowering individuals in the two populations is less than 110 (Criteria EN C2a and D). Because of all these factors the species should be considered Critically Endangered (CR) according to the IUCN Red List Criteria for Critically Endangered taxa (IUCN 2012, 2024).

Ethnobotany: —Plants of the new species are grazed by goats and sheep.

Paratype: — PAKISTAN. Balochistan, Zhob District, Cheena Mountain 31°26′04′′N, 69°15′06′′E, 1987 m, 30 October 2022, Nazar Khan & Tahir Khan (RAW barcode RAW103022).

Figures

FIGURE 2. Semenovia zhobica. (a–b) Habitat: Cheena Ghar Zhob & Tor Ghar Musakhail, respectively (c–d); Habit (e–f); Flowering and fruiting shoot.

FIGURE 3. Semenovia zhobica. (a) Basal leaf; (b) Upper cauline leaf; (c) Umbel; (d) Flower with petals removed showing stylopodium and calyx teeth; (e) Flower; (f) Dorsal side and commissural side of mericarp, respectively; (g) Mericarp with carpophore; (h) T.S. of mericarp.

FIGURE 4. Representative specimen of Semenovia zhobica (holotype RAW103023). Courtesy of the National Herbarium of Pakistan (Stewart Collection), National Agricultural Research Centre.

FIGURE 7. Distribution of Semenovia zhobica in grid map system of Pakistan.