Infraspecific

Infraspecific [ Taxonomy ]

Dictionary of botanic terminology - index of names

Of lower taxonomic rank than species.

In botanical nomenclature, an infraspecific taxon is a taxon at a rank below that of species, e.g. subspecies, varieties and other designations below the level of the species. Infraspecific taxon status ranks apply to plants and animal species, and the infraspecific taxon gets a ternary (trinomial) name. The third word in the scientific name, follows the name of the species.

In Mammillaria schiedeana subsp. giselae the word giselae is the infraspecific epithet.

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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