text: verbascum thapsus verbascum thapsus ( great mullein or common mullein ) is a species of mullein native to europe , northern africa , and asia , and introduced in the americas and australia . it is a hairy biennial plant that can grow to 2 meters tall or more . its small yellow flowers are densely grouped on a tall stem , which grows from a large rosette of leaves . it grows in a wide variety of habitats , but prefers well - lit disturbed soils , where it can appear soon after the ground receives light , from long - lived seeds that persist in the soil seed bank . it is a common weedy plant that spreads by prolifically producing seeds , but it rarely becomes aggressively invasive , since its seeds require open ground to germinate . it is a very minor problem for most agricultural crops , since it is not a very competitive species , being intolerant of shade from other plants and unable to survive tilling . it also hosts many insects , some of which can be harmful to other plants . although individuals are easy to remove by hand , populations are difficult to eliminate permanently . it is widely used for herbal remedies , with well - established emollient and astringent properties . remedies are especially recommended for coughs and related problems , but also used in topical applications against a variety of skin problems . the plant has also been used to make dyes and torches . description verbascum thapsus is a dicotyledonous plant that produces a rosette of leaves in its first year of growth . the leaves are large , up to 50 cm long . the second year plants normally produce a single unbranched stem , usually 1 – 2 m tall . in the eastern part of its range in china , it is , however , only reported to grow up to 1 . 5 m tall . the tall pole - like stems end in a dense spike of flowers that can occupy up to half the stem length . all parts of the plants are covered with star - shaped trichomes . this cover is particularly thick on the leaves , giving them a silvery appearance . the species ' chromosome number is 2n 36 . on flowering plants the leaves are alternately arranged up the stem . they are thick and decurrent , with much variation in leaf shape between the upper and lower leaves on the stem , ranging from oblong to oblanceolate , and reaching sizes up to 50 cm long and 14 cm across ( 19 inches long and 5 inches wide ) . they become smaller higher up the stem , and less strongly decurrent down the stem . the flowering stem is solid and 2 – 2 . 5 cm ( nearly an inch ) across , and occasionally branched just below the inflorescence , usually following damage . after flowering and seed release the stem and fruits usually persist in winter , drying into dark brown , stiff structures of densely packed , ovoid - shaped and dry seed capsules . the dried stems may persist into the following spring or even the next summer . the plant produces a shallow taproot . flowers are with ( usually ) five stamen , a 5 - lobed calyx tube and a 5 - petalled corolla , the latter bright yellow and an 1 . 5 – 3 cm ( 0 . 59 – 1 . 18 in ) wide . the flowers are almost sessile , with very short pedicels ( 2 mm , 0 . 08 in ) . the five stamens are of two types , with the three upper stamens being shorter , their filaments covered by yellow or whitish hairs , and having smaller anthers , while the lower two stamens have glabrous filaments and larger anthers . the plant produces small ovoid ( 6 mm , 0 . 24 in ) capsules that split open by way of two valves , each capsule containing large numbers of minute brown seeds less than a millimetre ( 0 . 04 in ) in size , marked with longitudinal ridges . a white - flowered form , v. thapsus f. , is known to occur . flowering lasts for up to three months from early to late summer ( june to august in northern europe ) , with flowering starting at the bottom of the spike and progressing irregularly upward ; each flower opens for part of a day and only a few open at the same time around the stem . taxonomy for the purpose of botanical nomenclature , verbascum thapsus was first described by carl linnaeus in his 1753 species plantarum . the specific epithet thapsus had been first used by theophrastus ( as , ) for an unspecified herb from the ancient greek settlement of , near modern syracuse , sicily , though it is often assimilated to the ancient tunisian city of thapsus . at the time , no type specimen was specified , as the practice only arose later , in the 19th century . when a lectotype ( type selected amongst original material ) was designated , it was assigned to specimen 242 . 1 of linnaeus ' herbarium , the only v. thapsus specimen . the species had previously been designated as type species for verbascum . european plants exhibit considerable phenotypical variation , which has led to the plant acquiring many synonyms over the years . introduced american populations show much less variation . the taxonomy of verbascum has not undergone any significant revision since mürbeck 's in the 1930s , with the exception of the work of arthur huber - , who used informal group in organizing the genus for the floras of iran and turkey to account for many intermediate species . since huber - 's groups are not taxonomical , mürbeck 's treatment is the most current one available , as no study has yet sought to apply genetic or molecular data extensively to the genus . in mürbeck 's classification , v. thapsus is placed in section subsect . ( or sect . verbascum subsect . verbascum depending on nomenclatural choices ) alongside species such as verbascum nigrum ( black or dark mullein ) , verbascum ( white mullein ) and verbascum sinuatum ( wavy - leaved mullein ) . subspecies and hybrids there are three usually recognized subspecies : v. thapsus subsp. thapsus ; type , widespread . v. thapsus subsp. crassifolium ( lam . ) . ; mediterranean region and to 2000 metres in southwestern austria . ( subsp. montanum ( . ) bonnier & ) v. thapsus subsp. giganteum ( . ) nyman ; spain , endemic . in all subspecies but the type , the lower stamens are also hairy . in subsp. crassifolium , the hairiness is less dense and often absent from the upper part of the anthers , while lower leaves are hardly decurrent and have longer petioles . in subsp. giganteum , the hairs are densely white tomentose , and lower leaves strongly decurrent . crassifolium also differs from the type in having slightly larger flowers , which measure 15 – 30 mm wide , whereas in the type they are 12 – 20 mm in diameter . both subsp. giganteum and subsp. crassifolium were originally described as species . due to its morphological variation , v. thapsus has had a great many subspecies described . a recent revision led its author to maintain v. giganteum but sink v. crassifolium into synonymy . the plant is also parent to several hybrids ( see table ) . of these , the most common is v. × . ( × v. nigrum ) . all occur in eurasia , and three , v. × fritsch , v. × and v. × l. ( syn . v. × ) , have also been reported in north america . common names v. thapsus is known by a variety of names . european reference books call it " great mullein " . in north america , " common mullein " is used while western united states residents commonly refer to mullein as " cowboy toilet paper " . in the 19th century it had well over 40 different common names in english alone . some of the more whimsical ones included " " , " indian rag weed " , " lungwort " , " adams - rod " , " hare 's - beard " and " ice - leaf " . vernacular names include innumerable references to the plant 's hairiness : " woolly mullein " , " velvet mullein " or " blanket mullein " , " beggar 's blanket " , " moses ' blanket " , " poor man 's blanket " , " our lady 's blanket " or " old man 's blanket " , and " " , and so on ( " flannel " is another common generic name ) . some names refer to the plant 's size and shape : " shepherd 's club ( s ) " or " staff " , " aaron 's rod " ( a name it shares with a number of other plants with tall , yellow inflorescences ) , and a plethora of other " x 's staff " and " x 's rod " . the name " velvet dock " or " mullein dock " is also recorded , where " dock " is a british name applied to any broad - leaved plant . distribution and habitat verbascum thapsus has a wide native range including europe , northern africa and asia , from the azores and canary islands east to western china , north to the british isles , scandinavia and siberia , and south to the himalayas . in northern europe , it grows from sea level up to 1 , 850 m altitude , while in china it grows at 1 , 400 – 3 , 200 m altitude . it has been introduced throughout the temperate world , and is established as a weed in australia , new zealand , tropical asia , la réunion , north america , hawaii , chile , hispaniola and argentina . it has also been reported in japan . in the united states it was imported very early in the 18th century and cultivated for its medicinal and properties . by 1818 , it had begun spreading so much that amos eaton thought it was a native plant . in 1839 it was already reported in michigan and in 1876 , in california . it is now found commonly in all the states . in canada , it is most common in the maritime provinces as well as southern quebec , ontario and british columbia , with scattered populations in between . great mullein most frequently grows as a colonist of bare and disturbed soil , usually on sandy or chalky ones . it grows best in dry , sandy or gravelly soils , although it can grow in a variety of habitats , including , meadows , roadsides , forest clearings and pastures . this ability to grow in a wide range of habitats has been linked to strong phenotype variation rather than adaptation capacities . ecology great mullein is a biennial and generally requires winter dormancy before it can flower . this dormancy is linked to starch degradation activated by low temperatures in the root , and application bypasses this requirement . seeds germinate almost solely in bare soil , at temperatures between 10 ° c and 40 ° c. while they can germinate in total darkness if proper conditions are present ( tests give a 35 % germination rate under ideal conditions ) , in the wild , they in practice only do so when exposed to light , or very close to the soil surface , which explains the plant 's habitat preferences . while it can also grow in areas where some vegetation already exists , growth of the rosettes on bare soil is four to seven times more rapid . seeds germinate in spring and summer . those that germinate in autumn produce plants that overwinter if they are large enough , while rosettes less than 15 cm ( 6 in ) across die in winter . after flowering the entire plant usually dies at the end of its second year , but some individuals , especially in the northern parts of the range , require a longer growth period and flower in their third year . under better growing conditions , some individuals flower in the first year . triennial individuals have been found to produce fewer seeds than biennial and annual ones . while year of flowering and size are linked to the environment , most other characteristics appear to be genetic . a given flower is open only for a single day , opening before dawn and closing in the afternoon . flowers are self - and protogynous ( with female parts maturing first ) , and will self - pollinate if they have not been pollinated by insects during the day . while many insects visit the flowers , only some bees actually accomplish pollination . v. thapsus ' flowering period lasts from june to august in most of its range , extending to september or october in warmer climates . visitors include halictid bees and hoverflies . the hair on lower stamens may serve to provide footholds for visitors . the seeds maintain their powers for decades , up to a hundred years , according to some studies . because of this , and because the plant is an extremely prolific seed bearer ( each plant produces hundreds of capsules , each containing up to 700 + seeds , with a total up to 180 , 000 or 240 , 000 seeds ) , it remains in the soil seed bank for extended periods of time , and can sprout from apparently bare ground , or shortly after forest fires long after previous plants have died . its population pattern typically consists of an ephemeral adult population followed by a long period of dormancy as seeds . great mullein rarely establishes on new grounds without human intervention because its seeds do not disperse very far . seed dispersion requires the stem to be moved by wind or animal movement ; 75 % of the seeds fall within 1 m of the parent plant , and 93 % fall within 5 m . bees of the genus use the hair ( amongst that of various woolly plants ) in making their nests . the seeds are generally too small for birds to feed on , although the american goldfinch has been reported to consume them . other bird species have been reported to consume the leaves ( hawaiian goose ) or flowers ( palila ) , or to use the plant as a source when foraging for insects ( white - headed woodpecker ) . fossil record seed of verbascum thapsus has been recorded from part of the cromer forest bead series and at west wittering in sussex from some parts of the interglacial layers . agricultural impacts and control because it cannot compete with established plants , great mullein is no longer considered a serious agricultural weed and is easily crowded out in cultivation , except in areas where vegetation is sparse to begin with , such as californian semi - areas of the eastern sierra nevada . in such ecological contexts , it crowds out native herbs and grasses ; its tendency to appear after forest fires also disturbs the normal ecological succession . although not an agricultural threat , its presence can be very difficult to completely eradicate , and is especially problematic in overgrazed pastures . the species is legally listed as a noxious weed in the american state of colorado ( class c ) and hawaii , and the australian state of victoria ( regionally prohibited in the west gippsland region , and regionally controlled in several others ) . despite not being an agricultural weed in itself , it hosts a number of insects and diseases , including both pests and beneficial insects . it is also a potential reservoir of the cucumber mosaic virus , ( the cucurbit powdery mildew ) and texas root rot . a study found v. thapsus hosts insects from 29 different families . most of the pests found were western flower thrips ( occidentalis ) , species such as the tarnished plant bug ( l. ) , and various spider mites from the family . these make the plant a potential reservoir for overwintering pests . other insects commonly found on great mullein feed exclusively on verbascum species in general or v. thapsus in particular . they include mullein thrips ( verbasci ) , ( whose larva consume the seeds ) and the mullein moth ( verbasci ) . useful insects are also hosted by great mullein , including predatory mites of the genera , and , the minute pirate bug and the mullein plant bug ( verbasci ) . the plant 's ability to host both pests and makes it potentially useful to maintain stable populations of insects used for biological control in other cultures , like verbasci and hesperus ( ) , a predator of whiteflies . a number of pest lepidoptera species , including the stalk borer ( ) and gray ( strymon ) , also use v. thapsus as a host plant . control of the plant , when desired , is best managed via mechanical means , such as hand pulling and , preferably followed by sowing of native plants . animals rarely graze it because of its irritating hairs , and liquid herbicides require surfactants to be effective , as the hair causes water to roll off the plant , much like the lotus effect . burning is ineffective , as it only creates new bare areas for seedlings to occupy . g. and verbasci usually have little effect on v. thapsus populations as a whole . goats and chickens have also been proposed to control mullein . effective ( when used with a surfactant ) contact herbicides include glyphosate , and - methyl . ground herbicides , like , are also effective , but recreate bare ground and require repeated application to prevent regrowth . uses great mullein has been used since ancient times as a remedy for skin , throat and breathing ailments . it has long had a medicinal reputation , especially as an astringent and emollient , as it contains mucilage , several saponins , coumarin and glycosides . dioscorides recommended it for diseases of the lung and it is now widely available in health and herbal stores . non - medical uses have included dyeing and making torches . medical uses dioscorides first recommended the plant 2000 years ago , against pulmonary diseases , and this has remained one of its primary uses , especially against cough . leaf or herbal teas were used for , consumption , dry cough , bronchitis , sore throat and hemorrhoids . leaves were also smoked against pulmonary ailments , a tradition that in america was rapidly transmitted to native american peoples . the zuni people , however , use the plant in poultices of powdered root applied to sores , rashes and skin infections . an infusion of the root is also used to treat athlete 's foot . the combination of saponins and emollient mucilage makes the plant particularly effective for cough . all preparations meant to be drunk have to be finely filtered to eliminate the irritating hairs . oil from the flowers was used against catarrhs , and , in germany , , frostbite , eczema and other external conditions . topical application of various v. thapsus - based preparations was recommended for the treatment of warts , boils , , hemorrhoids , and chilblains , amongst others . recent studies have found that great mullein contains compounds with and potential anti - action . these compounds are concentrated in the flowers . the german commission e sanctioned medicinal use of the plant for catarrhs . it was also part of the national formulary in the united states and united kingdom . the plant 's leaves , in addition to the seeds , have been reported to contain rotenone , although quantities are unknown . other uses like many ancient medicinal plants ( pliny the elder describes it in his naturalis historia ) , great mullein was linked to witches , although the relationship remained generally ambiguous , and the plant was also widely held to ward off curses and evil spirits . the seeds contain several compounds ( saponins , glycosides , coumarin , rotenone ) that are toxic to fish , and have been widely used as for fishing . the flowers provide dyes of bright yellow or green , and have been used for hair dye . the dried leaves and hair were made into candle wicks , or put into shoes to help with insulating them . the dried stems were also dipped into suet or wax to make torches . due to its weedy capacities , the plant , unlike other species of the genus ( such as v. ) , is not often cultivated . the stalk can also be dried as a spindle for making fire either by hand drill or bow drill .