Borderline carnivores

Brocchinea reducta (Bromeliad species)

The genus Brocchinea, a member of the Bromeliad family, includes in all 21 species. The species grow terrestrial in the south of Venezuela and also in Guiana and partly occur also on the Tepuis. Of the 21 species carnivorous plant fans are only interested in the species Brocchinea reducta, which is a funnel bromeliad of a maximum height of almost 50 centimetres. The funnel is liquid-filled, the leaves are covered with a wax film. In addition small, downward directed hairs are located in the low range of the leaves. On the wax film insects slip into the funnel, an escape is complicated on the one hand by the hairs, on the other hand by an agglutination of the insect feet by the wax. The status of Brocchinea reducta is disputed. It was long time considered as protocarnivorous plant, according to recent knowledge it should be able to produce itself enzymes thus.

The culture of this species is not easy. It requires a very light and humid location. As soil is recommended a loose mixture of peat, sand and perlites. In summer temperatures should not be above 25 °C by day, a significant drawdown during night is required. In winter temperatures should be circa 15 °C by day.

Catopsis berteroniana (Bromeliad species)

Also the genus Catopsis, likewise a member of the Bromeliead family, includes in all 21 species. Carnivorous plant fans are also interested in only one species, namely Catopsis berteroniana, which is an epiphytic funnel bromeliad of a maximum height of almost 100 centimetres. The funnel is liquid-filled, the leaves are covered with a thick wax film, which gives the plant a silver appearance. In this funnel fall apart from pollen and dust also insects, which are decomposed with the aid of bacteria. The species shall be able to absorb the degradation products. Because the plant does not produce itself enzymes yet, it is rated as borderline carnivore. The distribution area ranges from Florida to Middle America to East Brazil.

Cultivation of these plants is distinct easier as of Brocchinea reducta. About a successful culture on the windowsill was already reported, otherwise the conditions resemble more or less those of lowland-nepenthes. Preferred is a light, all-year warm and moist location. A slight drawdown during night is advantageous but not obligatory. The soil, which should be very loose (e.g. a mixture of peat, quartz sand, sphagnum moss and pine bark), should be kept evenly moist, but never soaked because waterlogging will kill the plant. A propagation is possible by seeds and layers.

Ibicella lutea und Proboscidea lousianica (Devil’s Claw)

For the sake of completeness I cite both species on this webpage, albeit I account these neither carnivorous nor protocarnivorous. In botanical terms it is already controversial, if the generic rank of Proboscidea is justified or the species lousianica ought not to regroup into the genus Ibicella, because both genera differ only very slightly from each other. Ibicella lutea originally comes from South America and is in the meantime naturalised in the south of the USA and also in parts of Middle America as neophyte. Proboscidea lousianica is also found in Mexico and in the Southern States. Both are annual, herbaceous, geranium-like plants with an unpleasant cadaveric odour. The plant is completely cluttered with glandular hairs, which secrete a polysaccharide-solution. The glands are to be found on the upper and on the lower surface of the leaf, on the stem as well as on the sepals. Merely the petales are unoccupied. Small flies are caught with the aid of the glands. An utilisation is proven neither by enyzmes nor by a decomposition by bacteria or fungi. All in all both species are not that carnivorous. They naturally grow on rather dry, nutrient-rich soils and especially Ibicella lutea can grow up to an one metre high plant within six months. They react on a fertilisation positive. For me, a posited carnivory of these species makes no sense in a evolutionary biologically view. The plants are rather to classify as nitrogen indicator, which prefer per se nutrient-rich soils. Which benefit do the plants have by a marginal higher nitrogen supply, which they should achieve by insect catch? Completely different is the situation with the other protocarnivorous and carnivorous genera, which all are to be found on nutrient-poor soils and react on a fertilisation often markedly negative. For me the glands are rather about a biological insect repellent, which should protect the plant from vermin. In my assessment the distribution of the glands, which are evenly to be found on the whole plant up to the petals, is indicative for this purpose too.

Triphyophyllum peltatum (Hooked Leaved Liana)

The Hooked Leaved Liana is indeed a real carnivorous plant, but only during one of three phases of life. The acute critically endangered Hooked Leaved Liana is currently only in botanical gardens in culture and comes from the rainforests of Africa’s west coast. Initial it is a grounded rosette, before height growth begins. In this stage the Hooked Leaved Liana evolves up to 25 cm long, filiform leaves, which function as passive flypaper traps and produce themself active enzymes for insect utilisation. In this second stage the plant obviously requires additional nutrients to enter the last stage. Then in the third stage the Hooked Leaved Liana continues growing as vine and can reach a length up to 50 m.