Leaves

http://fireflyforest.net/images/firefly/2005/July/Verbascum-thapsus-2.jpg

Through my own observations I've found that the leaves are fuzzy, having light colored hairs on the leaves. This helps prevent the leaves from drying out as well as assisting in keeping herbivores away. The leaves are large, and relatively smooth on the edges. The underside is not nearly as hairy as the top. It is still fuzzy however. The leaves are relatively thick with all the hair. The leaves as shown in the picture above spiral around the stock this is during the plants second - and last year. During the first year of this plant the plant is low to the ground, but still has that spiraling structure. The leaves on the bottom of the plant are larger in both width and length. The size tapers to allow light to hit those lower plants. Self-shading is a big issue for this plant, and this is the strategy it utilizes to overcome that issue.

The leaves are the most identifying structure on this plant, after which are the flowers. All that I have mentioned above I have self observed looking at these pictures posted here and through my own experience among them.

http://www.missouriplants.com/Yellowalt/Verbascum_thaspus_leaf2.jpg

Some things I found out about the plants are some of the medicinal uses of the leaves. I cannot vouch for these herbal remedies, botanical.com says people do this.

"The dried leaves are sometimes smoked in an ordinary tobacco pipe to relieve the irritation of the respiratory mucus membranes, and will completely control, it is said, the hacking cough of consumption. They can be employed with equal benefit when made into cigarettes, for asthma and spasmodic coughs in general" 

(http://www.botanical.com/botanical/mgmh/m/mulgre63.html#med).

I personally doubt adding smoke to your lungs - no matter the plant- would not be beneficial to your health. I will not be trying this method of healing a hacking cough.

Try it if you dare.