What does haustorium mean?
A haustorium is the specialized absorbing organ by which a parasite obtains nutrients from a living host. In parasitic plants, it grows into or attaches to the host's vascular tissue, drawing out water, minerals, and sometimes sugars or other organic compounds. Certain parasitic fungi form microscopic haustoria against host cells; these interface with the cell membrane and absorb nutrients without entering the cytoplasm. The word is therefore primarily a term of botany and mycology rather than general biology. Although its form may sound unfamiliar, the concept is familiar whenever one organism becomes physically linked to another for feeding: a mistletoe embedded in a tree branch, for example, is connected through a haustorium. The term is useful because it names the precise structure that makes parasitism possible and distinguishes the parasite's feeding connection from the tissues of the host itself.
nounA specialized feeding structure of a parasitic plant or fungus that establishes contact with host tissue and absorbs nutrients from the host. In parasitic plants it may penetrate the host's vascular tissue; in fungi it forms a microscopic interface with a host cell.
- Botany: The specialized organ of a parasitic plant that penetrates or attaches to host tissue and draws nutrients from it.
- Mycology: The specialized feeding branch of a parasitic fungus that absorbs nutrients from a host cell through an interface with the host plasma membrane.
"The mistletoe sent a haustorium into the oak branch and began drawing sap from the host."
"The mistletoe sent a haustorium into the oak branch and began drawing sap from the host."
"Microscopic imaging revealed the fungal haustorium pressing against the host cell membrane."
The standard plural is haustoria.
"The roots of the parasitic plant produced several haustoria that connected with the host's vascular tissue."
A haustorium is a parasite's living drinking straw: embedded in a host, it siphons nutrients from the tissue around it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does haustorium come from?
The word comes from New Latin haustorium, derived from Latin haustor, meaning "drawer" or "one who draws," and ultimately from haurire, meaning "to draw." Botanical usage applied the term by analogy to an organ that draws nourishment from a host. Its ultimate Latin root also underlies English words such as exhaust, exhaustible, and exhaustion, through Latin exhaurire.
Related word forms
How haustorium is actually used
This is a specialized term used chiefly in botany, mycology, and parasitology. It is uncommon in general discourse and is normally encountered in detailed scientific or educational contexts.
Easily confused with haustorium
A haustorium absorbs nutrients from a living host, whereas a haustellum is a sucking mouthpart, such as the coiled proboscis of a butterfly.