Hieracium pallidum subsp. amiatae Gottschl. & Selvi

Gottschlich, Günter, Selvi, Federico & Dunkel, Franz G., 2024, Hieracium pallidum subsp. amiatae (Asteraceae), a new subspecis from Monte Amiata (Tuscany, Italy), Phytotaxa 660 (2), pp. 198-204 : 199-200

Hieracium pallidum subsp. amiatae Gottschl. & Selvi , subsp. nov. ( Figs. 1–4 )

Type:— ITALY. Tuscany, prov. of Siena / Grosseto 1, Mt. Amiata , summit area (42°53ʹ14ʺN 11°37ʹ24ʺE), at several spots of trachytic rocks (ca. 50 plants), 1720–1728 m, 02.07.202 3, G. Gottschlich-81986 & F. G. Dunkel-41183 (holotype: FI; isotypes: Hieracia Europaea Selecta No. 1101 ( B, FR, H, IBF, LI, M, MSTR, PAL, W, Hb. Gottschlich-81986, Hb. Brandstätter, Hb. Dunkel-41183).

Paratypes:— ITALY. Monte Amiata sulla vetta, 1734 m, suolo siliceo, 04.07.192 4, A. Fiori ( FIAF 33819 ) ; Monte Amiata , sulle rocce trachitiche della vetta, 1730 m, 13.07.200 1, F. Selvi 1888 ( FI) ; Tuscany, prov. of Siena, Vetta del Monte Amiata , 20.06.201 8, G. Gestri (PI-021581, Hb. Gottschlich-71172) .

Diagnosis:— Hieracio pallido subspecie lanudo simile, sed involucrum pilis stellatis densissimis pilis glanduliferis multo minoribus obsitis.

Perennial, rhizome stout, oblique or vertical. Stem erect, vertical, cylindrical, stout (Ø 2 mm), (20)25–30(35) cm tall, often with 1–2 secondary stems, reddish green, striated, phyllopodous, with sparse to moderately dense 3–4 mm long, whitish, soft, simple and dentate hairs, sparse microglands and sparse to moderate stellate hairs. Basal leaves (2)3–4, with 2–4 cm long petiole, lamina 3–10 × 1.5–3.5 cm, elliptical to ovate-lanceolate, the lower part remotely dentate, the upper part slightly denticulate, bluish green, upper surface glabrous, margin with subdense, subrigid, sickle-shaped, 2– 3 mm long, white, simple hairs and scattered 0,1 mm long glandular hairs, lower surface with moderate 2–3 mm long simple hairs, stellate hairs absent. Cauline leaves (1)2, 2–8 × 1–3 cm, narrowly ovate to ovate-lanceolate, acuminate, the lower often inserted near the base and with a broadly winged 1.5–2 cm long petiole, the upper reduced in shape and with 0.5–1 mm long winged petiole or nearly sessile. Synflorescence paniculate, branches (1)2–3(4), straight or curved, (1)2–6(10) cm long, each with (1)2–3(4) capitula (sometimes abortive); capitula (2)4–6(10); acladium 1.2–1.5 cm long. Peduncles with 1–2 linear, 2 mm long bracts, with sparse 1 mm long white simple hairs, sparse 0.1 long glandular hairs and very densely covered with stellate hairs. Involucre campanulate, 8–10 mm long. Involucral bracts in few series, blackish green, linear-lanceolate, 1 mm wide, acute, with scattered 1 mm long simple hairs, scattered 0.2–0.3 mm long black glandular hairs, and very dense stellate hairs which give the whole involucre a white greyish appearance. Corolla limb ligulate, yellow. Styles yellow, margins of alveoli shortly dentate. Achenes brown.

Etymology:—The epithet amiatae refers to the type locality of Monte Amiata.

Phenology:—Flowering June and early July.

Distribution and ecology:— Hieracium pallidum subsp. amiatae is currently known only from the rocky summit area of Mt. Amiata. It grows in crevices of extrusive volcanic boulders of the trachytic type, in full light ( Fig. 4 ).

Conservation status:—The high visitor pressure caused by the attractiveness of the mountain in conjunction with undirected climbing on the rocks is proving to be very threatening for the new subspecies. The observations in the summit area show that many plants in accessible places were damaged by footfalls. Due to its restricted range and very reduced number of mature individuals (<100) and the actual partial damages by climbing activities Hieracium pallidum subsp. amiatae is to be listed as “Vulnerable” (VU) under criterion D2, according to IUCN criteria ( IUCN 2022).

To create more numerous microhabitats for this extremely small population, it would be useful to fell some beech trees in the immediate vicinity of the rocks, as H. pallidum subsp. amiatae does not tolerate shade.

Systematic affinities:—With its blue-green leaf colour and bristly pubescence, H. pallidum subsp. amiatae shows characteristics that clearly refer to H. sect. Oreadea Arvet-Touvet (1871: 47). However, the stem foliation shows an influence of H. sect. Grovesiana . Thus, this taxon belongs to H. pallidum Bivona ( Bivona-Bernardi 1838: 11). Although the name H. pallidum was previously used as the name for the collective species, which today bears the name H. schmidtii (e.g. Zahn 1921: 213; 1931: 243 and in many floras), it was shown on material from the type locality ( Gottschlich et al. 2013) that H. pallidum has morphological relationships to the species of H. sect. Grovesiana . This species also includes H. pallidum subsp. lanudae ( Gottschlich et al. 2013: 830) from the northern Apennines and 1 The border between the provinces runs over the top of the mountain. The new subspecies occurs on both sides of the border.

H. pallidum subsp. aetnense from Sicily ( Gottschlich et al. 2013: 826) ( Table 1 ; fig. 5 ). Like the latter subspecies, karyologically examined by Di Gristina et al. (2014), H. pallidum subsp. amiatae is tetraploid with 2n = 4x = 36 and capable of sexual reproduction ( Selvi & Fiorini 1996).

Figures

FIGURE 1. Hieracium pallidum subsp. amiatae, subsp. nov., isotype (Hb. Gottschlich-81986).

FIGURE 2. Hieracium pallidum subsp. amiatae, single capitulum.

FIGURE 3. Hieracium pallidum subsp. amiatae, single capitulum in nature (Photo: F. Selvi, 6.6.2022).

FIGURE 4. Hieracium pallidum subsp. amiatae, plant in nature (Photo: G. Gottschlich, 2.7.2023).

FIGURE 5. Distribution of Hieracium pallidum in Italy.