Type: — TURKEY. C6 Hatay, “Ad confinia Abetum [sic; sphalm. Abietum] in monte Akmadagh (Amano) Syriae bor. alt. 5600’ (Ky. Exs. 46!)”. Lectotype (designated here by M. G. Pimenov): P00753157 [fruiting fragments]; this voucher is undoubtedly connected to P00753162 [leaf fragment] (as ‘ H. amani ’, ad confinia Abietum in monte Akma Dagh, alt. 5600’, 21 June 1862, Kotschy -46), as both sheets are clearly annotated on their labels to belong to ‘ Drake’s collection’ at P; therefore they should be considered as initially being part of a single voucher, later marked with different barcode numbers (Art. 8.3 Ex. 4 of the ICN). Isolectotypes: P00753158, P00753159, P00753160, P00753161, C10008457, K000685828, W 0050238, W0050239, W 0050240, and W 0050241.

Description: Biennial, 0.9–1.2 m tall, aromatic herb. Stem solitary, 1.5–2.5 cm diameter below, finely striate-sulcate, glabrous in the lower part, subglabrous to sparsely pubescence in the upper part. Basal leaves 1-pinnate with pinnatisect segments or 2 pinnate; primary pinnae 3–4-paired; lamina triangular oblong and 40–70 cm long. Terminal leaf trisect. Ultimate lobes of leaves ovate to oblong, acute and dentate. All leaves sparsely short-adpressed pubescent above, more densely short-adpressed pubescent below with ovate-oblong sheaths. Central umbels 5–15 cm pedunculated. Rays 15–40, unequal, 4–10 cm in fruiting stage, short pubescent-setulose. Bracts 0. Bracteoles 0–1, filiform. Sepals and petals minute. Petals greenish white. Ovaries adpressed setulose. Stylopodium conical, 0.5–0.7 mm in flower, 1–1.5 in fruit. Style 1.5–2 mm in flower, the same length or deciduous in fruit. Mature mericarps obovate-orbiculate, c. 10 × 9 mm, occasionally adpressed setulose, emarginate, notch depth 1–1.5 mm. Endosperm 2.5–3.5 × 0.2–0.6 mm in cross-section, not extending up to the margins of the mericarp and not separating dorsal and commissural vittae from each other, c. 2/3–6/7 of the width of the marginal (outer) dorsal vittae are in contact with commissural surface. Commissural pericarp thin (c. 14 μm), translucent here, dorsal vittae becoming visible in the commissural surface. Dorsal vittae 4, broadly clavate c. 1–2 mm broad, c. ½ to ¾ as long as mericarp. Commissural vittae 4; the two central ones broadly clavate, c. 0.8–1 mm broad and ¼ as long as the mericarp; the two lateral ones ½ as long as mericarp (Fig. 1, 3Y, 4B, 5B, 6B, 7B, Table 1).

Flowering time: From May to July.

Recent collection: TURKEY. C6 Hatay: İskenderun-Kaledibi (vicinity of the type locality), 36°38’38.85”N 36°20’1.71”E, 1030 m elevation, 4 June 2015, S. Kayikci & Y.Güzel-20 (ANK; Herbarium of Mustafa Kemal University).

Distribution and proposed conservation status: Endemic to Amanos Mountains. It is represented by only one population within an area of less than 10 km 2. Besides having narrow distribution area, destruction of the habitat by human activities, e.g. urbanization and land clearing, threaten the population. So, it should be evaluated as critically endangered (CR) according to IUCN criteria (IUCN 2016)

Habitat observation from recent collection: Close to streams, under Platanus orientalis L. (1753: 999), or within the Fagus orientalis Lipsky (1898: 300) - Pinus nigra Arnold (1785: 8) mixed forest. Heracleum amanum occurs together with Quercus cerris Linnaeus (1753: 997), Pteridium aquilinum (L.) Kuhn (1879: 11), Centaurea lycopifolia Boiss. & Kotschy ex Boissier (1875: 693), Asperula cymulosa (Post) Post (1893: 22), Salvia tomentosa Miller (1768: without pagination), Tanacetum cilicicum (Boiss.) Grierson (1975: 434), Verbascum amanum Boissier (1879: 310), Carpinus orientalis Miller (1768: without pagination), Ostrya carpinifolia Scopoli (1772: 244) and Tilia argentea Candolle (1813: 150).

Carpological observations:

Heracleum crenatifolium: Endosperm of H. crenatifolium is wide and thick (3–4.75 × 0.4–1 mm). It extends up to the margin of the mericarp, and separates dorsal and commissural vittae from each other. Only a small proportion of the dorsal vittae (1/3–2/4 of their width) come into contact with commissural surface. Commissural pericarp is thick (42 μm) over the contact area. Therefore, dorsal vittae never become visible on commissural surface (Figs. 4A, 5A, 6A and 7A).

Heracleum amanum: Endosperm of H. amanum is narrow and thin (2.5–3.5 × 0.2–0.6 mm). It does not extend up to the margin of the mericarp, and does not seperate dorsal and commissural vittae from each other. Also, a large proportion of these dorsal vittae (c. 2/3–6/7 of their width) are in contact with commissural surface. Commissural pericarp is thin enough (c. 14 μm) to be translucent over the contact area. As a result, dorsal vittae become visible on the commissural surface (Figs. 4B, 5B, 6B, 7B).