Holotype

Holotype [ Taxonomy ]
Synonym: Type specimen
Abbreviation: HT

Dictionary of botanic terminology - index of names


	Also called type specimens or just type. A holotype is the single physical specimen of an organism selected by the original author of a species to be the standard-bearer for the new name which defines the characteristics of the whole species, or the illustration used as the basis for naming the species when no type has been selected.

Thus, a published holotype description becomes the official description of a new species, but the type specimen remains available to extend or modify that description in the future if it become necessary. The holotype plant is conserved (a process called curation) typically dried and kept in an herbarium. Biological collections are maintained by universities and museums. If more than one specimen was used to describe the species, then the other specimens apart from the holotype are called paratypes, although there is sometimes a risk that a paratype is not in fact of the same species as the holotype but a very similar one and so the description may not be accurate. There are many terms used to describe other example specimens of a species called biological types: • Paratype, A biological specimen other than the holotype used for the development of the original description. • Isotype, A duplicate specimen of the holotype collected in the same place and time. • Allotype a comparative specimen of the opposite sex to the holotype • Neotype a substitute specimen selected if the holotype was destroyed or otherwise lost • Isoneotype a duplicate of the neotype • Syntypes. two or more specimens describing of a new species when the author did not select a holotype. • Isosyntypes duplicates of a syntype. • Lectotype One single specimen later selected from the syntypes as the definitive type example • Paralectotypes After the definitive chosen of the lectotype the remainder syntypes become paralectotypes. • Epitype A later specimen used as an interpretative type when the holotype, lectotype, or neotype, is ambiguous.

Holdfast roots [ Botany ]
Dictionary of botanic terminology - index of names

Some species of climbing plants develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place.

Climbing plants, like the poison ivy (Toxicodendron radicans), Boston ivy (Parthenocissus tricuspidata), and trumpet creeper (Campsis radicans), develop holdfast roots which help to support the vines on trees, walls, and rocks. By forcing their way into minute pores and crevices, they hold the plant firmly in place. Usually the Holdfast roots die at the end of the first season, but in some species they are perennial. In the tropics some of the large climbing plants have hold-fast roots by which they attach themselves, and long, cord-like roots that extend downward through the air and may lengthen and branch for several years until they strike the soil and become absorbent roots.

Major references and further lectures:
1) E. N. Transeau “General Botany” Discovery Publishing House, 1994