Reproducing only by seed.
First year plant has no stems but just a rosette of large, gray woolly leaves. Second year plant has tall erect stems. Stem 1-2m high, stout, unbranched or with 1 or 2 branches near the top, somewhat winged by edges of leaves which run down the stem below their nodes. The stems are densely woolly.
First year plant is a rosette with many leaves, often 30cm long and 10cm wide. They are oblong or broadest beyond the middle, narrowed towards the stalk. Stem leaves of second year plants are a similar shape but gradually smaller upwards and changing from widest beyond the middle to widest before the middle and without leafstalks.
Flowers in a very dense, compact, elongated, thick spike. Five petals, yellow, united into a saucer-shaped corolla 12-20mm wide with 5 lobes. Stamens with 3 small anthers and 2 long ones. Seedpods are nearly spherical, about 1cm in diameter but obscured by the mass of woolly bracts and sepals. Seeds brownish, very small, about 0.7mm long. Flowers from early July to September.
Deep and thick taproot.
Common mullein is widespread throughout southern Ontario but rather rare in the northern part of the province, occurring usually in dry sandy or gravelly soils, along roadsides, waste places and poor pastures.
It is distinguished by its densely white or gray woolly leaves during the first year, almost resembling white felt insoles, its stiffly erect stem in the second year, tipped with yellow flowers (hence one local name, "Candelabra"), its leaf margins continuing down the stem as narrow wings, its very dense, thick, woolly spike with yellowish flowers and nearly spherical seedpods and its erect, dry, brownish stalks which may remain standing for one or two years.
Common mullein. A. Rosette of basal leaves. B. Top of flowering stem.
Densely wooly stem of mullein.
Lower leaf of common mullein.
Mullein plant on roadside in central Ontario, mid-July.
Mature seed head.
Cotyledons of common mullein.
4 leaf common mullein with cotyledons.
Seedling common mullein prior to bolting.
Leaf of common mullein showing the woolly texture.
Common mullein bolting and prior to flowering.
Yellow flower of common mullein.