Orostachys spinosa
by Kristl Walek
Orostachys is a member of the Crassulaceae family, which
includes other well-known succulents such as Sedum, Sempervivum and
Rhodiola. It is a small genus of plants classified into thirteen species
native to Russia, Mongolia, Korea, Japan, Kazakhstan and China. Most
are rubbery-foliaged plants with an outward growth habit. Some have
been, or still are classified as Sedums.
Orostachys spinosa is native to Siberia, Mongolia
and across Asia growing on dry, rocky slopes in the wild. In recent
studies of plants growing on the Russian desert-steppe, it was determined
"to be amongst the most cold-adapted plants known." It is
hardy to at least –40°C.
In
a genus of largely fleshy, spreading plants, O. spinosa is
the odd man out. It is often mistaken for a Sempervivum, although it
is decidedly more elegant; forming a low, spiny, grey, globose rosette
which can be 10cm across at maturity. This normally takes a minimum
of 5 years and at its peak, the plant is a wonder to behold and a perfect
study in symmetry. The rosettes are evergreen and emerge from winter
shrunken and tight, shimmering like grey-green metal. The rosette expands
and opens as the season progresses and changes to soft grey-green.
Like Sempervivum, O. spinosa is monocarpic, and
the individual rosette dies once it flowers. However, new rosettes form
in a circle at the base of the mature plant, which are normally removed
and grown individually. It is always sad when the flowering year arrives,
coinciding as it does with the plant's peak of perfection and size.
One knows when the time has come; the centre of the rosette bulges upward
and rises, turning into a wide-based
raceme
of insignificant small yellowish flowers. The phallic flower spike is
described in more polite circles as having the shape of "an inverted
ice-cream cone." Succulents are too rarely included in the rock
garden, notwithstanding the fascinating textual addition they can provide.
Orostachys spinosa in particular would look at home growing
with most alpines or planted in a trough.
Orostachys is fast from seed; moisture and a bit of warmth
quickly produce an ocean of plants. The seedlings are a bit of a challenge
to raise as they remain tiny for a long period and, like many cacti
infants, need more moisture than expected.