Uses
Several Desmodium species contain potent secondary metabolites. They are used aggressively in agriculture as part of the push-pull technology. Tick-trefoils produce extremely high amounts of antixenotic allomones - chemicals which repel many insect pests - and allelopathic compounds which kill weeds. For example, D. intortum and D. uncinatum are employed as groundcover in maize and sorghum fields to repel Chilo partellus stem-borer grass moths. They also suppress witchweeds such as Asiatic Witchweed (Striga asiatica) and Purple Witchweed (S. hermonthica).
Tick-trefoils are generally useful as living mulch and as green manure, as they are able to replenish soil fertility due to their nitrogen fixation. Most also give good animal fodder.
Some Desmodium species were shown to contain elevated amounts of tryptamine alkaloids. This is widespread in this genus and its relatives, and many tryptamine-containing plants treated in Desmodium are not placed herein anymore (see also below).
DMT and 5-MeO-DMT have been shown to occur in all green parts of D. gangeticum, as well as the roots. D. triflorum roots contain DMT-N-oxide.
There do not appear to be many animals that regularly feed on Desmodium, but detailed research in these interesting plants is lacking. Lesser Grass Blue (Zizina otis) caterpillars are known to feed in tick-trefoil, as well as, occasionally, those of the Two-barred Flasher (Astraptes fulgerator). Deer also appear to rely on the plant in certain areas, particularly during the stressful summer months.
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