The carnivorous plant encyclopedia - Chapter 2: plants for the advanced: Drosera (Sundew) - the dew imitator

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Drosera (Sundew):

Habitat:
Sundew is a very popular carnivorous plant among horticulturists, especially because of the great variety of sundew species (192 species), whose cultivation demands can differ immensely. Commonality of all sundew species are their very fine seeds that can spread over vast distances under windy conditions. In this way they rapidly vegetate stretches of wetland. Most sundew species can be found in Australia, South Africa and South America, while only a few are endemic to Europe, North America and Asia.

Cultivation:
As with most carnivorous species, ample sunlight, decent humidity and moist, low-nitrogen soil (preferably unfertilised peat moss or sphagnum) are the success formula for the sundew's health and growth. Moreover, if the plant does not have the typical fake dew droplets then this is indicative of too low humidity. Unclosed spherical glass containers are particularly suitable to create an ideal microclimate. Below are the most commonly cultivated sundew species.

Drosera rotundifolia:

This species, also called "round-leaved sundew", can be found in North America, Europe and Asia. They are hardy, which means they survive the winter weather, including severe frost, rather unscathed thanks to developing hibernacula. In a swampy mini biotope outside with plenty of sunlight and humidity they grow most lushly.

Drosera aliciae:

Endemic to South Africa, this species can be cultivated perennially warm, whereby especially during winter, however, a bright place is recommended. Fluorescent lamps might also help when there is a lack of sunlight, because otherwise they can rapidly become infected by gray mold, which entails the leaves' decay within the matter of days.

Drosera capensis:

Also endemic to South Africa, the Drosera capensis is the most frequently cultivated sundew species. In contrast to other species, it does not undergo dormancy, while ambient humidity allows the preservation of mucilage. Generally, cultivation measures of the Drosera capensis are very much the same as for the Drosera aliciae.

Trap mechanism:

Sundews' active adhesive traps are said to have one of the most beautiful leaf shapes in the world of flora. Although there is a wide diversity within the genus of Drosera the traps of all species function alike.

By means of viscous mucus glands on the leaf surface, which appear like dew droplets, sundew lures, catches and digests insects that feel drawn to the alluring light reflections of the mucus. Once caught, the entire leaf with all its tentacles will furl and then excrete its digestive juices to fully dip the insect into the mucus. After 1-2 weeks the digestive process is usually complete. The leaf unfurls back into its original state and any indigestive leftovers, mainly the chitinous exoskeleton, will be washed away by the rain. The carnivory serves the nutritional supply, mainly nitrogen, in poor soil conditions, yet the sundew itself doesn't draw any energy from the devouring of prey.

Much Love and Light,

Alex

Literature inspiration: Kosmos Garten: Fleischfressende Pflanzen

All Images: Pixabay, Flickr