Status: Exotic
Synonyms:
None
Verbascum thapsus is a tall unmistakeable plant. The leaves are mostly basal, and can reach very large size. They are woolly. The inflorescence is a tall crowded spike of yellow flowers. The stamen filaments are very hairy and the top of the style is flattened. Verbascum thapsus is a lower to middle elevation plant that grows on dry soil and on roadsides. The branching of the multicellular leaf cilia is quite interesting. The uppermost portion is stellate. Below the top, where there are cell junctions, there can be either another area of stellate branching or simple branching. So there are often areas of stellate branching stacked upon each other on the same main cilial stalk. The flowers mature into two-chambered stellate-pubescent capsules partially enclosed by leafy bracts. The capsules initially are green and then turn brown. After the capsules turn brown, they split open from the pointed apex toward the base revealing hundreds of minute, rugose brown seeds.
Please click on an image for a larger file.
verbascum_thapsus, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, May 19, 2007
Verbascum thapsus, flowering stem, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, May 30, 2007
Verbascum thapsus, detail of flower (note confluent anther sacs oriented at right angles to the filament), photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Oct. 30, 2008
Verbascum thapsus, 1x macro of leaf, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Nov. 27, 2008
Verbascum thapsus, 4x macro of leaf showing complex branching cilia (some with stacked stellate pattern), photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Nov. 27, 2008
Verbascum thapsus, 1x macro of stellate pubescent immature green capsule with leafy bracts, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 18, 2008
Verbascum thapsus, 1x macro of mature brown capsule splitting from apex, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 18, 2008
Verbascum thapsus, 1x macro of rugose, flat-ended seeds in brown capsule-- note that the seeds are less than a millimeter in length, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 18, 2008
Verbascum thapsus, 3x macro of rugose, flat-ended seeds in brown capsule, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, Dec. 18, 2008
Verbascum thapsus, photomicrograph of single complex leaf hair, photo Russ Kleinman, Pinos Altos Range, Pinos Altos, October 16, 2018
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