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Growth habit
A small spreading
succulent with a tuberous root system. They reproduce naturally by
means of
seed which germinates readily.
Decorative value
These
plants are being grown for their neat growth habit and attractive
flowers
Drought resistance
These
plants can survive periods of drought.
Disease and pest resistance
Unknown
Suitability as Green Roof plants
These
plants are valuable in plantings that are going to get the very minimum
of
or no water in winter as well in combinations with other plants that do
not have a
very vigorous nature
Biodiversity value in the Green
Roof landscape
Their flowers
attract
large numbers of insects in particular bees and small butterflies.
Cautions and precautions in the Green Roof
application
Care
must be taken to ensure good drainage in particular during
establishment.
Propagation
Cuttings and seed.
Crassulacean
acid metabolism
Drought responses of diurnal gas exchange, malic acid accumulation and
water status in Delosperma tradescantioides. When well watered, this
species exhibited Crassulacean acid
metabolism (CAM)-cycling, but its carbon fixation pattern
changed during the development of drought, shifting to either low-level
CAM or to CAM-idling. The rate and pattem of this change depended on
environmental conditions, duration of water stress and leaf age. At the
onset of drought, diurnal malate fluctuation increased, but was
strongly depressed (by ca 70%) as drought continued, and when leaf
water content and water potential were low (ca 35 and 50% of the
initial levels, respectively). When rewatered, rates of growth and
photosynthesis, gas exchange and water status recovered fully to
pre-stressed values within two days. Whole-shoot carbon uptake rates
suggested that leaf growth had continued unabated during a short-term (
one week) drought. This emphasizes that CAM-idling allows the
maintenance of active metabolism with negligible gas exchange when soil
water is limiting. It is possible that old or senescent leaves may
provide water for the expansion of developing leaves during initial
periods of drought. Regardless of the water regime and environmental
conditions, leaf nocturnal malate accumulation and water content were
positively correlated and increased with leaf age. Thus the gradual
loss of water from older mature leaves may induce CAM-idling, which
reduces water loss. An important ecological consequence of this
combination of CAM modes is the potential to switch rapidly between
fast growth via C3 gas exchanges when well-watered to
water-conserving CAM-idling during drought.
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