Verbascum bombyciferum

Biennials. Stems 60–200 cm, densely and persistently tomentose, eglandular. Leaves: surfaces densely and persistently tomentose, eglandular; basal and proximal cauline with petiole 15–40 mm; blade broadly elliptic to lanceolate-oblong, 25–35 × 15–25 cm, base attenuate; cauline slightly auriculate-clasping, gradually smaller distally, base not decurrent, margins obscurely crenate or entire, apex of distal cauline and floral bracts acute. Inflorescences unbranched or branched from proximal nodes, narrowly cylindric, flowers loosely overlapping, in clusters of 2–8; rachis densely and persistently tomentose, eglandular; bracts ovate to lanceolate-triangular, 7–12 mm, base not decurrent, apex acuminate, densely and persistently tomentose, eglandular. Pedicels free, 2–5 mm; bracteoles 2. Flowers: calyx 6–10 mm, densely and persistently tomentose, eglandular, lobes lanceolate to narrowly lanceolate; corolla yellow, (20–)30–40 mm diam., pellucid glands absent; filaments villous, hairs yellowish to yellowish white, or 2 proximal glabrous distally or completely; stigma spatulate, base decurrent. Capsules ovoid to subglobular, 5–8 mm, tomentose.

Phenology: Flowering Jun–Sep.
Habitat: Grassy, rocky benches, streambeds.
Elevation: 300–500 m.

Introduced; Calif., Asia (Turkey), introduced also in Europe (England, Germany).

Discussion

Verbascum bombyciferum is naturalized in Sonoma County, escaped from ornamental plantings in 1976 at a residence on the Pepperwood Preserve (F. Hrusa et al. 2002). Photos of the population (http://www.calflora.org) show plants (intermixed with typical V. thapsus) with a dense, persistent, bright white vestiture, spikes unbranched or proximally few-branched and 1–2 m, the floral clusters thick and somewhat remotely arranged, yellow corollas with yellowish to yellowish white filament hairs, and broadly elliptic, basally attenuate leaves densely and persistently tomentose on both surfaces. Internet photos confirm the identification as V. bombyciferum and indicate that the Calflora photos show plants just beginning to flower, as the plants potentially elongate proximally and the spikes may develop lateral branches, although the central one usually remains dominant.

Verbascum bombyciferum of Sonoma County has been identified previously (F. Hrusa et al. 2002) as V. olympicum Boissier, and that name has correspondingly been registered in other literature. Verbascum bombyciferum (as well as V. olympicum) is endemic in native range to Mount Olympus (now known as Uludağ) in northwestern Turkey.

Selected References

None.

Lower Taxa