Roridula dentata is one of only two species in this genus. It gets its name from the Latin words roridos meaning dewy and dentata meaning toothed.
R. dentata is a perennial shrub up to 2.5 meters in height. It occurs in the seasonal dry Fynbos of the mountains near Clanwilliam, Tulbagh and Ceres at 900 till 1200 meters a.s.l. Only 20 populations of this plant are known.
The plant has a woody stem with lanceolate leaves of about 6 cm long that are placed in up to 400 rosettes on an adult plant at the tip of the branches.
It is clearly distinct from R. gorgonias by having highly serrated and divided leaf margins. Flowers occur on the tip of the plant in the months September – October.
Flowers are about 2 cm in diameter and pink, with more or less oval petals. Each flower can produce only three seeds.
Roridula is unusual as a carnivorous plant in that is doesn’t produce enzymes to digest captured pray and that the trapping mechanism is not a glue but a resin.
The resin is much stronger than the average glue found on Drosera and consequently the plant is capable of capturing large prey. To digest this pray the plant lives in symbiosis with assassin bugs (Pameridea marlothii). These bugs are capable of moving on the plant without being caught and suck the fluids from the captured prey to feed themselves. Their excrements are absorbed by the plant enabling it to benefit from its catch.
Besides the above mentioned bugs, there are also spiders living on this plant. It is assumed, that they have an important rule in controlling the bugs population.
Cultivation is difficult in that it is hard to get the seeds to germinate. The plant needs a well drained 50/50 mix of sand and peat and should be kept moist but not wet. Do not disturb the root system!
If one is lucky enough to get some seeds of this plant it should be known that they need some special treatment to germinate. Seeds of Roridula dentata germinate only after fires in their habitat. To break the dormancy of the seeds you will have to use some tricks. Placing the seeds into smoke water or using GA3 (gibberellin acid) are two of the more common practices to pretreat the seeds.
As R.dentata is limited to only 20 populations the species is very much endangered. On top of this the plant lives in a fire based ecosystem that due to human interventions sees less and less fires. The most acute danger to these natural populations however is the continuing growth of the plantations were Rooibos tea is grown. It is therefore of paramount importance that all lineages are retained in cultivation and propagated to preserve the natural variation of this species. If you grow distinct location forms that are not in the Rare South African carnivorous plants Collection, and are willing to donate or sell plants, cuttings or seeds of legally cultivated plants to Ark of Life, please contact the team through this contact page of this website.
If you cultivate R. dentata, but are unable to contribute material to the Rare South African carnivorous plants Collection, however would still like to help save this species, please register your plants with Ark of Life, so that we can develop a breeding program and record all location forms of this critically endangered plant in cultivation.
nest of a spider, that lives on Roridula dentata
one of the spiders, that live on Roridula dentata
assassin bug of the genus Pameridea