Sun plant
Due to their structure and metabolism, solar plants or light plants (heliophytes) are adapted to locations with very strong solar radiation. The sun plants include the mullein , the heather , the thyme and the silver thistle . They are often found in open fields, on rocks, dry grass and in heather .
Special features include coarse little leaves with hair and a wax coating to protect against excessive light radiation and water loss. The structure of the leaves differs through the frequently observed double palisade layer . The chloroplasts also have protective devices such as carotenoids and enzymes that prevent an accumulation of reactive oxygen compounds that are toxic. In addition, there are more stomata on the leaves to allow a stronger gas exchange. This also increases the rate of photosynthesis .
In contrast to shade plants, sun plants have a high light compensation point , i. that is, they need higher light intensities to effectively fix carbon dioxide . Sun leaves perform very well, up to . However, compared to other leaves, they have a higher basal metabolic rate.
