Variety traits

Drought tolerance of beard tongue

Penstemon Schmidel.

This trait is determined by the plant's response to water stress, measured through physiological indicators and morphological changes. The level of tolerance varies from high values in arid species to low tolerance in garden hybrids.

In the reference 8 varieties crop Beard Tongue, where this is mentioned in the description.

To assess the drought tolerance of Penstemon, methods of controlling substrate moisture content are used, with the recording of morphological changes such as height, diameter, and shoot dry mass. The physiological response is analyzed by measuring photosynthetic rate, stomatal resistance, and canopy temperature, while in P. barbatus and P. strictus species, an increase in leaf reflectance during dehydration is additionally recorded.

Species adapted to arid conditions, such as P. strictus and P. pinifolius, possess high tolerance to moisture deficit. Conversely, garden hybrids adapted to regular watering, as well as representatives of alpine origin, show low drought tolerance, responding to soil drying with wilting and chlorosis.

Agrotechnically, the drought tolerance of Penstemon is closely linked to drainage requirements: even drought-adapted species are extremely sensitive to waterlogging. Insufficient watering in less tolerant hybrid forms leads not only to a loss of turgor but also to significant shifts in the phenological cycles of flowering and fruiting.

General information about the subject — on the page Drought tolerance.

Sources8

Varieties of Beard Tongue mentioned in the description

Selection based on the description text, not on official evaluation: these data are absent from registers. For specific variety details, please refer to its profile.