May offend Homework / test English to Spanish Art/Literary Poetry & Literature guidebook

I have come across the adjective 'vicious' applied to plants, especially those with spines:

I have thought of 'puñetero/a' but I am not sure.

A whole series of plants have defence mechanisms to deter hungry animals. Wolfbane (Periploca angustifolia or cornical) exudes a very irritating milky latex if anything tries to eat it. Rascamoños (Launaea arborescens, no English name) protects itself with vicious terminal spines on its branches. Retama, mentioned above, contains the alkaloid sparteine, found also in some species of broom, a substance that herbivores find particularly unappetising and, for the same reason, the sage-leaved rock rose (Cistus salviifolius or jaguarzo moriscos) has a high concentration of tannins.

OR
Capers

At irregular intervals by the sides of the track that winds up towards the summit of Cerro de Los Lobos, there are in winter, prostrate, dead, woody shrubs. Some of them poke improbably from cracks in cliffs where it would seem there could be no nutrient to sustain a plant. From the end of May onwards these woody skeletons transform themselves into vibrant green plants with short-lived pink and white flowers of exquisite beauty. Each flower opens early in the morning and dies in the roasting heat a few hours later. These are capers (Capparis spinosa in Latin). The prized parts of the plant are the flower buds, alcaparras in Spanish, which can only be picked by hand and then only with great care, as the stems have vicious backward-curving spines. The smaller the heart-shaped flower bud is when picked, the tastier it will be. The best are reckoned to be those that are no more than 7 mm across. If the buds are allowed to flower they then produce fruits that look like tiny striped green rugby balls. These, alcaparrones in Castilian, are also picked and processed but do not quite have the same striking flavour as the buds.

ALSO

Agaves
There are approximately 300 species of agaves. The commonest agave in eastern Almería is the inaccurately-named century plant, aka American agave (Agave Americana/planta del siglo or pita). It’s another striking incomer from Mexico. From a dramatic basal rosette of strap-like fleshy leaves, often well over a metre long and armed along their edges with short but vicious spines, the agave throws up a hefty flower spike in much less than the hundred years suggested by its common name. The time from seed to flowering is more typically between 10 and 30 years. Atop the wooden, trunk-like flower spike, evenly-spaced and elegantly curved side branches hold sprays of almost insignificant flowers which evolve into hard pods that fall to produce a new generation of tiny agaves. This is assuming the house sparrows, which are attracted to the seed pods like wasps to jam, don’t consume all the seeds first. The spent parent agave is monocarpic; it flowers just the once, then dies. Locals know this agave as pita.