After I've shown you Conyza canadensis (L.) Crouq. from the Asteraceae family; i want to present you another species of this Genus: Conyza sumatrensis (Retz.) E. Walker, also from the Asteraceae family. Common English names are “fleabane” or “white horseweed”, while in Germany we call it “Weißliches Berufskraut”.
C. sumatrensis - habitus
The species looks similar to C. canadensis an can reach heights until 1 or even 2 metres. It has long, thin leaves, which looks similar to the leaves of a dandelion (however, here the whole shoot is leafy)
The inflorescences are panicles. Like all Asteraceae, these panicles consist of heads, which consist of many radial flowers with five white petals per flower in the periphery and many tubular flowers with five greenish petals per flower in the centre.
C. sumatrensis - inflorescences
So, the radial flowers are simulating a corolla, while their bracts form a fake calyx. These fake flowers are typical for the Asteraceae. It lets the flowers look greater and more attractive for pollinators.
C. sumatrensis - habiuts
Despite it's name, C. sumatrensis is not native to Sumatra but to North America. However, today this species can be found everywhere in world. In Europe it came as Neophyte in the Mediterranean and later to Germany, England or Ireland. It grows at ruderal wastelands, roadsides and between stones. In contrast to C. canadensis, which is the most common species, C. sumatrensis is more rare.