Parasitism is a universal trait. I’ll relate here how a plant uses it successfully : lovely inflorescences and thus reproductive prowess, with no need to harness solar energy and turn it into chemicals.
This plant is native to the whole circum-mediterranean region from Greece and Albania to Portugal and Morocco, including islands such as Cyprus, Malta, Corsica, Sardinia, Sicily, the Baleares and the Canary Islands. The flowers, yellow to reddish, number 5-10.
The Latin name Cytinus derived in antiquity from the Greek kytinos, because of the resemblance both Theophrastes and Dioscorides saw in pomegranate flowers. A common name in French is cytinelle.
It infects two species predominantly, Halimium halimifolium and Cistus montpeliensis.
The roots are the site of attack, the parasite nests within the roots of the host. Besides lacking roots itself, it has neither a stem nor leaves. Accordingly, it lacks chlorophyll and fully relies on its host for energy and chemicals. Its genome is tiny, with only 23 genes. Ants pollinate it.
Parasitism: the parasite takes but gives nothing in return. Its host gives, but receives nothing. Cytinus illustrates this universal trait. Its parasitism of Cistus involves a tall shrub (50-120 cm) and itself tiny in comparison, 5-10 cm. No wonder if the former can safely ignore the diminutive latter.
Parasitism can take place, in other cases, where there is no discrepancy in size.
There are cases, in both nature and human society, in which the bigger preys on the smaller. No, I am not about to paraphrase the Communist Manifesto! What I’d like to mention instead is the occasional occurrence of the misdeed among scientists.
Indeed, the academe is not immune to parasitism. There is plagiarism, of course. There are other versions, in addition, less prone to opprobrium and punishment. I knew a colleague, very clever as an undercover parasite, who sought the usual professional rewards of advancement and prizes, while an exploited underling was doing, not only the hard work, supplying the ideas as well.
Coming back to Cytinus, hungry people have used this plant for food, especially during hard times of scarcity and famine. The young plant can been cooked as a substitute to asparagus — I have yet to try it!