Senecio joharchii Ghahremaninejad et al. (2010: 27)

Calvo, Joel, Álvarez, Inés & Aedo, Carlos, 2015, Systematics of Senecio section Crociseris (Compositae, Senecioneae), Phytotaxa 211 (1), pp. 448-450 : 448-450

28. Senecio joharchii Ghahremaninejad et al. (2010: 27) . TYPE: Iran, Northern Khorasan Province, Esfarayen, Saluk National Park , mt. Ahangaran , 37º13'23''N 57º13'35''E, 16 April 2008, A. Ezazi & N. Rahchamani 4692 (holotype, FAR not seen; isotypes, FAR image!, TUH not seen).

Perennial herb. Stem ca. 17 cm, erect, leaved, not ramificated, densely arachnoid-floccose. Basal leaves 3–9 cm long, 0.8–1.8 cm wide, persistent, oblanceolate, obtuse, attenuate to cuneate, with a petiole 3–6 cm long, entire to denticulate towards the base, densely arachnoid-floccose, concolorous. Middle cauline leaves 7.5–10 cm long, 1.2–1.6 cm wide, alternate, oblanceolate, obtuse, sometimes acute, semiamplexicaul, entire to denticulate towards the base, densely arachnoid-floccose, tertiary venation inconspicuous; upper cauline leaves 1.5–7 cm long, 0.2–0.9 cm wide, acute, sessile, densely arachnoid-floccose. Synflorescence reduced to a solitary capitulum. Capitula 1; involucre 18–20 mm in diam., cupuliform; involucral bracts 32–35, 9–10 mm long, 0.8–1 mm wide, lanceolate to oblong, long-attenuate, apex violet coloured with a black spot at the summit, arachnoid-floccose; supplementary bracts 13–16, 2.5–4 mm long, 0.5–1 mm wide, subulate, widened at the base, without scarious margin, a quarter to a three-quarters as long as involucral bracts, apex violet coloured with a black spot at the summit, arachnoid-floccose, not imbricated or slightly so at the base. Ligulate florets ca. 12, ca. 10 mm long, yellow; tubular florets ca. 6 mm long, yellow. Achenes 1.2–1.5 mm long, shorter than pappus, with scattered trichomes; pappus 4–6 mm long, whitish. Chromosome number: unknown. Figure 21 .

Iconography: — Ghahremaninejad et al. (2010: 28, fig. 1).

Distribution and habitat: — Iran, northern Khorasan Province; habitat unknown; elevation of ca. 1900 m ( Figure 32 ).

Phenology: — Flowering from April to May.

Etymology: — The specific epithet honors an Iranian plant taxonomist, Mohammad-Reza Joharchi, who develops his career at FUMH herbarium, Ferdowsi University of Mashhad, Mashhad, Iran.

Discussion: — This is a new species that is recently described and only known from the type material, and therefore, scarce information about it is available. Since the efforts to obtain specimens for examination were unsuccessful, the biometric data here presented are based on the protologue. Nonetheless, some pictures of one

SYSTEMATICS OF SENECIO SECTION CROCISERIS

Phytotaxa 211 (1) © 2015 Magnolia Press • 85 isotype allow us to recognize it as a separate species. The leaf indumentum, number of involucral bracts, and number and size of the supplementary bracts discriminate this species from S. paulsenii subsp. khorasanicus , which also grows in the Khorasan Province. Senecio joharchii has the leaves densely arachnoid-floccose, while those of S. paulsenii are glabrescent to weakly arachnoid. The number of involucral bracts is clearly higher in S. joharchii [32–35 vs. (14–)20–21(–24)]. Concerning the supplementary bracts, these also differ in number (13–16 in S. joharchii vs. (5–)6–9(–14) in S. paulsenii ) and size (widened at the base in S. joharchii vs. linear-oblong in S. paulsenii ).

The number and shape of both involucral and supplementary bracts are very similar to those of S. provincialis from NE Spain and SE France, and also they usually bear solitary capitulum. In this case, basal leaves are useful to distinguish each other. Senecio provincialis has its basal leaves ovate to lanceolate, glabrescent to covered with scattered arachnoid trichomes above, arachnoid to slightly lanate beneath, usually discolorous. On the other hand, S. joharchii has its basal leaves oblanceolate to lanceolate, densely arachnoid-floccose on both faces, concolorous. Moreover, it differs from S. provincialis in the apex of the involucral bracts that is violet coloured with a black spot at the summit. The stem base is also violet coloured, a character more frequent among the Crociseris species from Central Asia.

Taking into account that the isotype studied was just starting to bloom, the length measurements of the ligulate flowers and the achenes are questionable. More collections are needed in order to improve the knowledge of some morphological characters and distribution, and to understand the variability of S. joharchii .

Figures

FIGURE 21. A–I. Senecio olympicus Boissier—a. Habit (drawn from Boissier s.n. July 1842, L).—b. Habit (drawn from Davis 37377, E).—c. Capitulum (drawn from Davis 37377, E).—d. Involucral bract (drawn from Davis 37377, E).—e. Supplementary bract (drawn from Davis 37377, E).—f. Ligulate floret (drawn from Davis 37377, E).—g. Tubular floret (drawn from Davis 37377, E).—h. Achene (drawn from Nydegger 14050, G).—i. Indumentum of achene (drawn from Nydegger 14050, G). J–L. Senecio joharchii Ghahremaninejad et al. (drawn from Rahchamani 4692 & Ezazi, FAR, as image)—j. Capitulum.—k. Involucral bract.—l. Supplementary bract.

FIGURE 32. Distribution map for Senecio paulsenii subsp. khorasanicus (Rechinger & Aellen) Nordenstam (▲) and S. joharchii Ghahremaninejad et al. (●).