Story om en manätande växt i en annan dimension

Jätte köttätande växter är ett vanligt föremål för science fiction, och författarna släpper dem ofta med tentaklar för att ta tag i bytet. Jag har inte hittat en exakt matchning för din historia, men du säger att det är en gammal historia och du nämner resor till en annan dimension, och det här gör mig omedelbart att tänka på Clark Ashton Smith eller andra som skriver i samma stil. Han var oerhört förtjust i äventyr i andra dimensioner - ofta eldritch dimensioner.

Det finns ett träd som liknar din beskrivning i hans novella Marooned i Andromeda , men som Titeln skulle föreslå att detta inte sker i en annan dimension utan snarare på en planet i Andromeda-galaxen. Jag läste det i antologin Andra dimensioner vol 1 när jag var ungefär tio och älskade det - jag Ägna fortfarande så mycket bok:

Hur som helst är scenen med trädet:

Adams ventured to take a step forward. Instantly a long tentacle shot out from the nearest of the kraken-like forms and encircled him. Struggling and screaming, he was drawn toward the great dark lumpish mass from which the tentacles emanated. There was an open cup-like mouth of vermilion, fully a yard wide, in the center of this mass; and before his companions could even move, Adams was thrust into the mouth, which forthwith closed upon him like the mouth of a tightened sack. Roverton and Deming were petrified with horror. Before they could even think of stirring from where they stood, two more of the tentacles shot out and gripped each of them about the waist. The grip was firm as an iron rope; and both were conscious of a sort of electric shock at the contact—a shock which served to stun them still further. Almost fainting, they were held erect by the horrible coils.

Nothing more happened for a brief interval. The incomprehensible strangeness of their position, the manifold fatigues and ordeals of the day, together with the shock of those coils, had dazed the two men so that they could hardly grasp the fate of their companion and their own imminent doom. Everything became unreal, misty, dream-like. Then, through the vagueness that enveloped their senses, they saw that the dark mass at the core of the tentacles was beginning to move and heave. Soon the heavings turned to convulsions that became more and more violent. Roverton and Deming fell to the ground as the coils loosened their hold, and saw the lashing of a score of tentacles in the air above, tossing from side to side about the agitated central mass. Then, from this mass, the body of Adams was ejected, to fall beside Roverton and Deming. Obviously human flesh had not agreed with the digestion of the Andromedan plant-monster. The mass continued to heave and palpitate, and its myriad arms waved through the air as if in agony

Till och med på 1970-talet var Clark Ashton Smiths historier mestadels i antologier, och jag undrar om du kanske har läst historien i en antologi och conflated den med andra berättelser om hans olika dimensioner. Det är ett långt skott, men jag tyckte det var ett försök att värda.