Centaurea kuhdashtensis Ranjbar & Mohamadi, 2021

Ranjbar, Massoud, Askari, Ali & Mohammadi, Somayeh, 2021, Two new species of Centaurea sect. Microlophus (Asteraceae, Cardueae) from Iran, Phytotaxa 480 (2), pp. 125-138 : 132

2. Centaurea kuhdashtensis Ranjbar & Mohamadi , sp. nov. Figs. 7–9 .

Diagnosis:— Centaurea kuhdashtensis is similar to C. koeieana but differs by hispid (vs. arachnoid) hairs, upper cauline leaves decurrent for 3–10 mm (vs. 2–7 mm), lower cauline leaves 35–38 × 10–11.5 cm (vs. 15–17 × 2–3.5 cm), median [lower] cauline leaves pinnatipartite- pinnatilobate or pinnatifid (vs. lanceolate or lanceolate-oblong), margin entire-dentate (vs. irregularly dentate or entire), segments lower cauline leaves 15–17 pairs (vs. no segment), basal cauline leaves 44–46 × 13–15 cm (vs. 15.5–17 × 2–3 cm), basal cauline leaves pinnatipartite-pinnatilobate or pinnatifid (vs. oblong lyrate or pinnatilobate), basal cauline leaves 14–15 pairs (vs. 1–2), margin basal cauline leaves irregular dentate (vs. dentate or lobate), involucres 10–16 × 5–7 mm (vs. 15–18 × 5–8 mm).

Type:— IRAN. Lorestan, Bolouran to Baba Zeyd, 65 km to Baba Zeyd , 35 km to Kuhdasht , 33° 33’ 22’’ N, 47° 18’ 01’’ E, 1504 m, 1 May 2013, M . Ranjbar 33645 (holotype: BASU) .

Perennial plants with thickened rootstock, usually completely green up to 80 cm tall, in the lower part loosely covered with hispid hairs. Stem erect, often branched above, sometimes branched in the median to upper parts striate striped, many branched, usually striped, 1–3 mm in diam. at base, cylindrical. Sometimes ascending, branched often at the base, or branched in median part, thinly white striate, rigid densely leafy throughout. Leaves and stem loosely hispid, venation actinodromous at basal and lower stem leaves. Basal cauline leaves pinnatipartite, pinnatilobate or pinnatifid, 44–46 × 13–15 cm, terminal segments larger, lanceolate-linear, lateral segments 14–15 pairs, lanceolate-linear, segments sometimes lobed near the base, acute at apex, margin irregular dentate. Lower cauline leaves pinnatipartite to pinnately divided, odd pinnate in outline, 35–38 × 10–11.5 cm, terminal segments larger, oblong-lanceolate, lateral segments 15–17 pairs, oblong-lanceolate, segments sometimes lobed near base, acute at apex, margin dentate. Median [lower] cauline leaves pinnatipartite, pinnatilobate or pinnatifid, odd pinnate in outline, 10–13 × 3–5 cm, margin entire dentate, decurrent for 15–20 mm, margin dentate, venation reticulate. Median [upper] cauline leaves sessile, simple oblong-lanceolate, 9–10.5 × 0.8–0.9 cm, acute to acuminate at apex, decurrent for 40–50 mm, perfoliate, margin entire. Upper cauline leaves sessile, simple, oblong to oblong-lanceolate in outline, 1–3 × 0.3–0.5 cm, shortly decurrent for 3–10 mm, acuminate at apex, venation reticulate, margin entire. Involucres conical contracted towards top, diamond, 10–16 × 5–7 mm. Phyllaries multiseriate, imbricate, coriaceous, yellowish or green, hairy. Outer phyllaries ovate, 3–5 mm long. Median phyllaries ovate to oblong 6–8 mm long, spine 1 mm long. Inner phyllaries oblong, 10–12 mm long. Appendages forming a minute deciduous tip, not decurrent, outer phyllaries deciduous, inner phyllaries persistent, always small, not concealing the basal part of phyllaries. Flowers yellowish-green; central flowers hermaphrodite, up to 14 mm long; peripheral sterile, not radiant, limb lobes linear. Achene oblong, 1–2 mm long. Pappus multiseriate, scabrous, the outer 3–6 mm long, the inner much shorter.

Etymology: —The specific epithet refers to Kuhdasht city, near which the type specimens were collected.

Phenology: —Flowering March (second half) to May.

Distribution and habitat: — Centaurea kuhdashtensis occurs in Kuhdasht area, a mountainous region in western Lorestan province, Iran. Phytogeographically it is an Irano-Turanian element and grows in dry clay, stony slopes and screes, at 1400–1600 m ( Fig. 6 ).

IUCN Red List category: — Centaurea kuhdashtensis is known from a few small populations, consisting of no more than five plants, observed in the mountains between Bolouran and Baba Zeyd village (M. Ranjbar, pers. obs.). According to the IUCN Red List criteria ( IUCN 2001), this species could be classified as Critically Endangered (CR). This category includes taxa in which fewer than 50 mature individuals exist.

In recent years, several morphological and molecular studies have been done on this section ( Garcia-Jacas et al. 2006). The evaluated morphological characters were most suitable for separating Centaurea dezfulica from C. pabotii and C. kuhdashtensis from C. koeieana ( Table 1).

Figures

FIGURE 6. Distribution of Centaurea in Iran. A, C. dezfulica, B, C. pabotii, C, C. kuhdashtensis and D, C. koeieana.

FIGURE 7. Centaurea kuhdashtensis (M. Ranjbar 33645, BASU). Scale = 5 cm.

FIGURE 8. Centaurea kuhdashtensis (M. Ranjbar 33645, BASU). A1, close up of capitula, B1–B3, outer phyllaries, C1–C3, median phyllaries, D1–D3, inner phyllaries, E, leaf stomata, F and G, leaf indumentum. Scale A = 1 cm.

FIGURE 9. Measured morphological characters in Centaurea kuhdashtensis (M. Ranjbar 33645, BASU). A, middle stem leaf, B, central floret, C, involucre, D, involucral bract. For character explanations see Table 1.