In the novel The plant can be divided into three components: base, trunk, and head (which contains a venomous sting). Adult triffids are typically in height. European triffids never exceed ; however, in tropical climates, they can reach . The base of a triffid is a large muscle-like root mass, comprising three blunt appendages. When dormant, these appendages draw nutrients, as on a normal plant. When active, triffids use these appendages to propel themselves. The character Masen describes the triffid's locomotion thus: Above the base are upturned leafless sticks which the triffid drums against its stem. The exact purpose of this is not explained; it is originally assumed that they are part of the reproductive system, but Bill Masen's colleague Walter Lucknor believes they are used for communication. Removal of the sticks causes the triffid to physically deteriorate. The upper part of a triffid consists of a stem ending in a funnel-like formation containing a sticky substance which traps insects, much like a
pitcher plant. Also housed within the funnel is a stinger which, when fully extended, can measure in length. When attacking, a triffid will lash the sting at its target, primarily aiming for its prey's face or head, with considerable speed and force. Contact with bare skin can kill a person instantly. Once its prey has been stung and killed, a triffid will root itself beside the body and feeds on it as it decomposes. Triffids reproduce by inflating a dark green pod below the top of the funnel until it bursts, releasing white seeds (95% of which are infertile) into the air. and rooting themselves beside houses, waiting for the occupants.
In other adaptations and sequels The triffids portrayed on screen and in sequels often differ in appearance from Wyndham's original concept. In
Steve Sekely's 1962
film adaptation, the triffids (now given the
binomial name Triffidus celestus) were designed with flaying tentacles below their stems, which they use as slashing weapons and to drag their dead prey. Also, their stinger is shown as a gas-propelled projectile, rather than a coiled tendril. Finally, the film triffids are vulnerable to
sea water. The 2009 TV adaptation shows the triffids dragging themselves with prehensile roots which can also constrict their prey. Their stalk is surrounded by large
agave-like leaves and they secrete their oil (green rather than the novel's pink) from their surfaces. Their stingers, which in previous film adaptations could not penetrate glass, are powerful enough to shatter windows, like those of the original triffids of the novel. Instead of a cup they have a pink flower-like head, resembling a cross between a
lily and a
sweet pea, that enlarges before releasing the sting. In the
Simon Clark sequel novel
The Night of the Triffids, a small number of North American triffids reach in height. Aquatic triffids also appear but remain largely unseen, with the exceptions of their stingers: the latter described as
prehensile. One character in the novel, Gabriel Deeds, speculates that the vibrations made by the triffids' sticks serve as a form of
echolocation. encouraging the elimination of the
Chromolaena odorata weed ==Other mentions of the triffids==