Relictual

Relict [ Biology - Ecology ]	Dictionary of botanic terminology - index of names
Adjective: Relictual

Surviving remnants of a formerly widespread species or group in certain isolated areas but which is extinct over much of its former range.

In biology a relict is an organism that at an earlier time was abundant in a large area but that now persist at only one or a few small areas. A survivor(s) from a previous geological era or from earlier (different) climatic conditions, a remnant of an otherwise extinct flora or fauna in an environment much changed from that in which it originated
The distribution of a relict is characterized as endemic. An example of a relict is a remnant or fragment of the vegetation of an area that remains from a former period when the vegetation was more widely distributed.
The term "relict" can also refer to an ancient species that survives while related species go extinct, the last survivor of an otherwise extinct group The Gingko biloba is an example of this type of relict.

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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