Verbascum × sipiadense Zograf.

Zografidis, Aris, Esser, Hans-Joachim, Dimopoulos, Panayotis & Raus, Thomas, 2022, Typification of the names Verbascum limnense and Celsia tomentosa (Scrophulariaceae) and a new nothospecies, V. × sipiadense, with the hybrid formula V. limnense × V. sinuatum, Phytotaxa 542 (2), pp. 214-220 : 216-218

Verbascum × sipiadense Zograf.

( V. limnense × V. sinuatum ), nothosp. nov.

— Type: GREECE. Nomos Evvias , Eparchia Chalkidos : Island Evvia, just outside the settlement of Sipiada (near Limni) on roadsides, 38°46’N, 23°16’E, 30 m, 5 May 2018, Zografidis 360 (holotype UPA! ; isotype ATH!). Fig. 3 .

Diagnosis: Intermediate between the parental species V. limnense and V. sinuatum but sterile. Differing from the former by having the lamina of basal leaves coarsely crenate to lobed (vs. crenate to subentire), leafy flowering stems (vs. subaphyllous), up to 4-flowered glomerules (vs. solitary flowers), bracteoles present (vs. bracteoles absent) and bicoloured, white-violet stamen hairs (vs. white). Differing from the latter by the presence of long eglandular hairs at the base of the petioles of rosette leaves, 2- to 7-flowered glomerules (vs. 1- to 4-flowered), glabrous outer surface of corolla (vs. stellate-tomentose) and bicoloured stamen hairs (vs. violet).

Description: Sterile biennial herb producing a basal leaf rosette in the first year of growth and an erect, terete, leafy flowering stem 1–1.8 m of height in the second year. Indumentum covering the aerial part of the plant eglandular, grayish-yellowish, persistent. Rosette-leaves petiolate with petioles 1–8 cm long, base of petioles with longer hairs; lamina obovate to obovate-elliptic, coarsely crenate to lobed, attenuate to petiole, obtuse at apex, 7–30 × 2.5–10 cm. Lower cauline leaves similar but ±sessile. Middle and upper cauline leaves sessile, progressively smaller, ovate-oblong to ovate-triangular, crenulate, subacute to acute, the upper ones ca. 2 × 1 cm. Inflorescence freely branched from below, lax. Flowers solitary or in groups (glomerules) of 2–4; bracts c. 2 × 1 mm, ovate-lanceolate, acute; bracteoles present, lanceolate; pedicels 1–3 mm. Calyx 2–3 mm, segments lanceolate-oblong, acute, divided almost to the base. Corolla yellow, 2–2.5 cm in diameter, with pellucid glands, outer surface glabrous, inner surface glabrous or with simple hairs on the proximal part of upper lobes (on the central vein of the lobe); stamens 4(–5) with medifixed anthers; filament hairs white and violet. Capsules not formed.

Notes: Natural hybrids between Verbascum spp. are readily produced when species coexist, whereas all hitherto described hybrid taxa are invariably sterile (e.g., Murbeck 1933, Huber-Morath & Rechinger 1960). It is also noted that, unlike V. × sipiadense, the parental species V. limnense always exhibits white stamen hairs, not violet ones as cited in former literature ( Ferguson 1972, Trigas 2003, Strid 2016a). It is thus hypothesized that the various descriptions of V. limnense in previous floras might have been partially based on heterologous material consisting of the new nothospecies.

Figures

FIGURE 3. Holotype of Verbascum × sipiadense Zograf. kept in UPA (UPA-29510).