Hermetospheres

Experiences with plant life in closed glass containers

Latest Articles

Vivipary in two Gesneriads

In viviparous plants, the embryo grows sufficiently to emerge visibly from within the seed tissues before dispersal (Farnsworth 2000: 108). The number of plant species for which vivipary belongs to the usual form of reproduction in their natural habitats is relatively small. However, in some plant species where this form of reproduction is unusual, vivipary…
Read more: Vivipary in two Gesneriads
The blue iridescence of the red Selaginella

Iridescence is the name of shimmering blue metallic colors of certain plants that appear to change as the angle of view changes. You can find out how it is produced in Selaginella erythropus, why it cannot be seen with the bare eye and how unusual this is in the plant kingdom. Before that, it is…
Read more: The blue iridescence of the red Selaginella
Tuberous miniature Sinningias

Mini sinningias are popular terrarium plants. With their geophytic life cycle, are they also suitable for the hermetosphere with its steady conditions? Information on the natural habitat, experiences from growers and an experiment should provide some insight.
Read more: Tuberous miniature Sinningias
An under-researched plant family

Usually, when I place a new plant in a new hermetosphere, I want to know its identification down to species level. I have several reasons for this. In most cases, identifying the species is a prerequisite for obtaining information about its natural habitat. This information is helpful to assess whether or not a plant is…
Read more: An under-researched plant family
The Hoya from Kanyakumari

Wax plants (genus Hoya) are popular houseplants. At least this species from southern India also thrives in the hermetosphere. This is the impression I got from my journey with H. kanyakumariana during the first year.
Read more: The Hoya from Kanyakumari
The olive-coloured begonia

First collected presumably in 1979 and scientifically described 10 years ago, Begonia olivacea is established in the terrarium plant trade by now, both as potted plants or seed. According to the recommendations for cultivation given by the nurseries, the hermetosphere is bound to provide the perfect conditions for the plant. It is described as lithophytic…
Read more: The olive-coloured begonia
Succeeding generations (3): Ludisia discolor

If hermetospheres are supposed to last over years, it is advantageous to work with plants that are able to produce offspring under the particular restrictions given (a.o. limited space, unlikely pollination). The terrestrial orchid Ludisia discolor has its own way of ensuring offspring in the absence of pollinators. The key to this type of vegetative propagation…
Read more: Succeeding generations (3): Ludisia discolor
Two great naturalists and a miniature plant

It is hard to imagine a plant more inconspicuous than Selaginella microphylla: tiny leaves on a uniform, branched shoot, monochromatic green, without flowers. Nevertheless, it was collected in 1801 or 1802 during an expedition through the rough wilderness of the northern Andes, carefully labelled, preserved, transported to the Pacific coast and shipped to Europe together…
Read more: Two great naturalists and a miniature plant
Nutrient recycling

In a previous post, I explained why I minimize the nutrient content in my hermetospheres and how I calculate how many nutrients I add to my substrate to start with. Even though nutrients are meant to be scarce, it can happen that a plant grows too tall or too wide for the container. The reasons…
Read more: Nutrient recycling
Succeeding generations (2): Begonia pteridoides

When plants produce second and third generations is one of my best rewards when working with hermetospheres. Plants have several ways to do this, e.g. seeds or runners, and not always it is quite clear when a next generation actually begins. In the case of Begonia pteridoides shown here, the situation should be unambiguous.
Read more: Succeeding generations (2): Begonia pteridoides