Distribution
Artemisia rupestris is apparently a glacial relict that survived in places
without strong competition from other plants. Currently, the species occupies
a large distribution range in Siberia, the northern Central Asia and the
mountains of Middle Asia. It grows there in larch forests, meadows, steppes,
rocky slopes, margins of lakes and rivers. Sometimes it occurs in salty places
(Jäger 1987). Frequently, the species is confined to mountainous areas.
Jäger (1987) documented the decline of the species in Europe and its
reasons. Reasons were mainly meliorations and a subsequently increasing
competitive pressure by species previously excluded from these moist and
salty places. Intensive collections by botanists may also have contributed to
the declining populations. A poultry farm opened in 1960 close to the last
occurrences at Artern (Saxony-Anhalt) led to a further dramatic decrease of
the population size. In 1979 Dr. F. Ebel and collaborators found only one
remaining plant/clone of A. rupestris among a dense stand of A. maritima.
Cuttings were transferred to the Botanical Garden Halle and were the stock
for this first ex-situ conservation project. The last plant at Artern was freed
from competition and kept alive throughout the years. Without these effort
the plant would have disappeared in the region. The next and certainly also
relic occurrences are in the Baltic area.
Biology and growth
Artemisia rupestris is a mat forming, partly evergreen perennial. Creeping
ramets are much more frequently than inflorescences. The inflorescences are
formed in at least two phases. Roots are formed along the creeping twigs.
For further information on the growth pattern and morphology, see Jäger
(1987).
The plants are apparently self-fertile, but usually the achenes do not become
ripe in our area. Only once seedlings could be observed (H.-G. Fuhrmann).
Conservation
Vegetative propagation of the plants is performed by division of the older
plants. This can be performed throughout the year and is made every year. It
is thus not yet clear weather the clones age.
Special demands to soil quality do not exist. We take ordinary substratum
from the garden. One problem with rich soils is that the plants may die after
flowering due to exhaustion. In poor sandy soils this phenomenon appears
less frequently. Usually, we cut the inflorescences in summer or early autumn.
Pots with plants of A. rupestris were regularly watered. If growing in open
conditions, the plants get rarely additional water or only from adjacent
sprinklers.
The plants are completely hardy, only the pots were covered during the
winter by pine brushwood.
Maintenance of genetic diversity
The plants are clonally propagated. Every graft from the original population is
divided every year. Usually, on half is maintained for conservation, the rest is
discarded or used for plantings in the garden. Plantings are in the Botanical
Garden and in a garden designed for the maintenance of rare species at the
Kapenmühle (Biosphärenreservat Mittlere Elbe).
Literature
Ebel, F. Rauschert, S. (1982): Die Bedeutung der Botanischen Gärten für
die Erhaltung gefährdeter und vom Aussterben bedrohter Arten. Arch.
Naturschutz u. Landschaftsforschung 22, 187-199.
Jäger, E. J. (1987): Biologie, Chorologie und Ursachen des Reliktcharakters
von Artemisia laciniata Willd. und A. rupestris L. im herzynischen Gebiet.
Hercynia N. F. 24, 425-436.
Text (c) Botanischer Garten Halle: M. H. Hoffmann, F. Ebel, H.-G.
Fuhrmann, E. Stollberg, 2006