Moth Mullein, Slippery Mullein, Wild Verbascum

Verbascum blattaria

ver-BASK-um  blat-TAR-ee-uh

Synonyms of Verbascum blattaria (29) (Updated on 12-26-23 from Plants of the World Online): Blattaria vulgaris Fourr. (1869), Thapsus blattaria (L.) Raf. (1838), Verbascum blattaria var. albiflorum Kuntze (1891)(nom. illeg.)Verbascum blattaria f. albiflorum (G.Don) House (1923), Verbascum blattaria var. brevipedicellatum Halácsy (1892), Verbascum blattaria var. crenatum Rouy (1909), Verbascum blattaria var. incarnatum Regel (1868), Verbascum blattaria var. majus Gaudin (1828), Verbascum blattaria var. normalis Kuntze (1891)(not validly publ.), Verbascum blattaria subsp. repandum (Willd.) Arcang. (1882), Verbascum blattaria var. rubricaule Regel (1868), Verbascum blattaria var. subintegerrimum Regel (1868), Verbascum blattariforme Griseb. (1852), Verbascum carduifolium Murb. ex Hayek (1929), Verbascum caucasicum Fisch. (1812)(nom. illeg.), Verbascum claytonii Michx. (1803), Verbascum cordatum Desf. (1798), Verbascum glabrum Mill. (1768), Verbascum leptophyllum Bubani (1897), Verbascum luridum Salisb. (1796), Verbascum nitidum Stokes (1812), Verbascum ramosissimum J.Lloyd ex Boreau (1868)(nom. illeg.), Verbascum repandum Willd. (1809), Verbascum rhinanthifolium Davidov (1915), Verbascum rubiginosum Diard (1852)(sensu auct.), Verbascum virgatum Spreng. (1824)(nom. illeg.)

Verbascum blattaria L. is the accepted scientific name for this species of Verbascum. The genus and species were named and described as such by Carl von Linnaeus in the first volume of the first edition of Species Plantarum in 1753. 

As of 12-26-23 when this page was last updated, Plants of the World Online by Kew lists 465 species in the Verbascum genus. It is a member of the plant family Scrophulariaceae with 58 genera. Those numbers could change as updates are made by POWO.

The above distribution map for Verbascum blattaria is from Plants of the World Online. Areas in green are where the species is native and purple is where it has been introduced. The map on the USDA Plants Database for the United States and Canada is the same. The species has been reported in Montana and Wyoming even though the maps don’t show it… 

The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations. The maps on iNaturalist are continually updated as members post new observations.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.

While I was working on a friend’s farm in the summer of 2019, I ran across several species of wildflowers I hadn’t encountered. On June 3, I spotted a spread-out colony of neat plants with white flowers. With the help of iNaturalist and Missouri Plants, I found out the species was Verbascum blattaria. Then, on June 19, I ran across the same species in a different location on the same farm with yellow flowers. The plants were in full sun and there was a slight breeze so I was unable to get “knock your socks off” close-ups. I haven’t seen this species anywhere else nor have I been wildflower hunting back on that farm since 2019. 

Verbascum blattaria is a biennial species introduced to North America from Eurasia. This species is easy to identify from its raceme of interesting flowers, globe-shaped buds and fruit, and clasping leaves. 

This species prefers full sun in moist to dry conditions. It will grow in poor soil with gravel or clay, but fertile soil with adequate moisture will produce much larger plants, up to 3’. They can be found along stream banks, in fields and pastures, in ditches, along railroads and roadsides, and in open disturbed areas. A disturbed area means the area goes through seasonal changes. 

Plants grow to 1 1/2 to 5’ tall on erect stems, sometimes branching toward the top, 4-angled or ribbed, usually glabrous (not hairy) to slightly pubescent (hairy) toward the top.

Since this species is biennial, first-year plants only form a rosette of leaves from 5 to 16” or so in diameter. Leaf blades are oblanceolate, have coarse teeth along the margin, and can be scalloped or pinnately lobed. The leaves are attached to the stem by a short-winged petiole or they may be sessile (no petioles). In the second year, the leaves grow in an alternate pattern along the stem that are shorter than those of the rosette. The leaves grow up to 5” long and 2” wide, but get smaller as they progress up the stem. The leaves are dark green, oblanceolate, glabrous (not hairy), or pubescent (hairy) toward the top. The lower leaves clasp the stem while the upper leaves toward the inflorescence are sessile or with short petioles (leaf stems). The margins are coarsely toothed, finely toothed, and scalloped toward the tip.

The stems terminate in an open raceme of flowers up to 2’ long. The flowers, one per node, are attached by a short peduncle (flower stem).

The stem along the inflorescence and the foliaceous bracts surrounding the flowers have short glandular hairs.

The 5-lobed corollas, 1/4 to 1” across, are attached to the stem by 1” long peduncles (flower stems). The corollas can be white or yellow and have a pinkish-purple color at the base. The 5 lobes are fused together at the base.

There are 5 stamens with orange anthers. The upper 3 stamens have shorter filaments (stalk of the stamen) bearded with purple and white hairs. The lower two are longer, angled somewhat downward, with purple hairs. The anthers of the two lower stamens are fused to the filaments. There is a single pistol with a knobby orange stigma. GEEZ! I am sure I missed something… Oh, yeah! The corollas are subtended by a calyx with narrowly elliptic to narrowly lanceolate lobes. The calyx and peduncles have short glandular hairs…

I want to give special thanks to Steve Ash for allowing me to use his great photo of a Verbascum blattaria flower. Mr. Ash has been an iNaturalist member since July 22, 2018. He joined the same year I did.

The flowers open from the bottom toward the top of the raceme. By the time the flowers in the center open, there will be fruit at the bottom, flowers in the center, and buds on top.

The 2-celled ovaries become the seed capsules that contain numerous seeds. I read on one site that each plant produces 1,000 capsules. Hmmm… That would mean 1,000 flowers per plant! I suppose if a plant had enough branches, say 20, it could get close. Anyway, in an experiment conducted at the Michigan Agriculture College, seeds of several species were placed in glass bottles and turned upside down in a sandy knoll in 1879. In 2000, 23 seeds of Verbascum blattaria were planted and they had a 50% germination rate. That’s 121 years!

I have enjoyed photographing and learning about the many wildflowers growing on the family farm and in other areas. The farm is in Windsor, Missouri in Pettis County (Henry County is across the street, and Benton and Johnson aren’t far away). I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of the page). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a few horticulturalists I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.

I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at thebelmontrooster@yahoo.com. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
FLORA OF MISSOURI (GENUS/SPECIES)
FLORA OF NORTH AMERICA (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
WORLD PLANTS
USDA PLANTS DATABASE
DAVE’S GARDEN
MISSOURI PLANTS
UNIVERSITY OF MISSOURI WEED ID GUIDE
iNATURALIST
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
PFAF(PLANTS FOR A FUTURE)
GO BOTANY
FLORA FINDER
MARYLAND BIODIVERSITY PROJECT
INVASIVE PLANT ATLAS
OHIO PERENNIAL & BIENNIAL WEED GUIDE
THE JEPSON HERBARIUM
U.S WILDFLOWERS

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is one of the most reliable and up-to-date plant databases and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂