Planthets

Planthets are a fictional category of life forms described in speculative biology and science fiction as plant-like organisms capable of locomotion. The term is used in various works to explore how blurred boundaries between plants and animals might operate in different environments. In typical depictions, planthets resemble thalloid or stalked plants with photosynthetic tissue and chlorophyll, but they also possess mobility: slow crawling, creeping, or directed movement facilitated by flexible tissues, hydrostatic pressure changes, or filamentous extensions. This combination yields organisms that appear rooted yet can relocate to optimize light, moisture, or nutrient uptake.

Morphology varies widely: some planthets have a compact, basal holdfast with extendable, leaf-like blades; others form drifting mats that can reorient and shift position. Reproduction is commonly asexual, through budding, fragmentation, or spore-like propagules; occasional sexual cycles are imagined to occur under environmental stress.

Ecology and distribution in fiction place planthets in diverse habitats, from shaded forest floors to rocky coastlines. They function as primary producers, often engaging in mutualisms with fungi or bacteria and serving as substrates for detritivores. Their mobility can influence ecosystem dynamics by enabling rapid colonization of microhabitats and response to changing light or moisture.

Notes: Planthets are not recognized by real-world biology and are primarily a thought experiment or world-building device. See also speculative biology, xenobionts, and plant-like life forms in fiction.