Plants of the
#Rafflesiaceae (
#Malpighiales, Rosids) are
#biologically #interesting, but also morphologically striking and impressive. They include the largest
#blossoms in the
#plantkingdom.
Although the flowers may be visually pleasing to the human observer, closer inspection reveals a familiar color palette, albeit for rather unpleasant reasons. It is reminiscent of dead flesh, i.e.,
#rotting #carcasses. This is an
#evolved #strategy in which a plant imitates something both visually and through its activity (=
#mimicry). Rafflesiaceae not only look like animal carcasses, but they also
#smell like them. Through this mimicry, the plant attracts
#carrionflies, which then carry out
#pollination. The
#seeds, on the other hand, are
#dispersed by somewhat larger animals, such as
#rodents.
These plants are
#endoparasites of the plant genus
#Tetrastigma (
#Vitaceae), meaning they do not photosynthesize or absorb nutrients from the soil. Instead, they are connected to their host and obtain photosynthetic products, minerals, and water from it.
A rare example from this taxon is
#Sapria #himalayana, which practices a strong form of this parasitism. It is connected to the phloem and xylem of the host plant via its root-like organs (
#haustoria). It is widespread in the Eastern
#Himalayas (see X link of W. Chen, 2025).
The authors J. Molina et al. (2024) were the first to study the
#microbial #partners of a species, namely
#Rafflesia #speciosa, within the Rafflesiaceae. By comparing the bacterial fauna in sections of the host plant with that of Rafflesia seeds, they found that the seeds possess
#bacterialprofiles that correspond to those of the host plant. According to the authors, these bacteria appear to have been
#sequestered from the
#host plant.
©
#StefanFWirth Berlin 24 December 2025
References:
X link of W. Chen, 2025
x.com/i/status/2002483963051…
J. Molina et al. (2024)
doi.org/10.1080/17429145.202…
#Pictures:
Rafflesia
#arnoldii, the best known species with the largest blossoms, native to
#Indonesia,
#AIassisted #illustrations, edited manually, © Stefan F. Wirth, 24 December 2025
This fascinating holoparasite belongs to the family Rafflesiaceae; it usually grows on lianas such as Vitis and Tetrastigma spp., and its relatives (afflesia spp.) in Southeast Asia have the largest flowers in the world. So excited to see it in Yunnan, China. Sapria himalayana.