Ever since the first of our arboreal ancestors studied and understood the function of a pitcher plant, or E, perhaps a Venus fly-trap, the idea of a vegetable growth which could and would entrap and absorb a human has been one of the well-springs of nightmare. For some reason the thought of becoming breakfast food for an outrageous orchid or perhaps an overbloated sweet potato holds more intrinsic horror than the fangs of the tiger or the tentacles of the kraaken.
Since such plants are uncommon, if indeed they exist at all, upon Earth, it is perhaps natural for imaginative authors to envision them as existing upon alien planets. Furthermore, the mere removal of such growths across a few parsecs of space does nothing to remove the immediacy of their terror, a fact which Mr. MacDonald makes extremely evident. —The Editor