noun, countable. plural is haustoria. Related adjective is haustorial
A haustorium is the organ through which a parasitic plant is attached to a host plant. It attaches itself to the host and then penetrates the host conductive tissues. It serves as a form of root for the parasite, forming a physiological bridge through which nutrients pass from the host to the parasite. It is the defining feature of parasitic plants. Haustoria may take the form of either a primary or secondary haustorium.
Collocation - haustorium may be used as a modifier as in haustorium development, haustorium penetration or haustorium size, but is usually modified itself. The following examples show whether the haustorium is active or has failed functional, abortive haustorium or give its age young, mature haustorium
Haustorium is often associated with certain verbs
The primary haustorium is a haustorium that develops at the apex of the young root that emerges from the parasite seed. It attaches itself to the host root before penetrating the host tissues and seeking the conductive elements located inside the host root .
Secondary haustoria may develop laterally from the primary root system of the parasite or on adventitious roots developing from parasite shoots. These provide further contact between the host roots, or branches in the case of aerial parasites such as mistletoe, and the parasite. This is particularly true in facultative parasites that do not have a primary haustorium. In some cases secondary haustoria allow the parasite to be attached to more than one host.
adjective haustorial. Related noun is haustorium
The adjective haustorial is often used to talk of the physiological aspect, haustorial cells, the process of formation and attachment, haustorial initiation, haustorial penetration, or the place of attachment, haustorial interface