San Gabriel Valley Cactus and Succulent Society
Succulents of the Month September 2007  Monadenium and Jatropha
The genera Monadenium and Jatropha are close
relatives of Euphorbia. While Euphorbia and
Jatropha are world wide genera, Monadenium is
confined to Africa, with a large part of the genus
in tropical Africa. Both genera share the same
milky sap as Euphorbia.
Monadenium spinescens
There are about 75 species, of Monadenium with
many discovered recently, and more certainly to be
found. Like Euphorbia, there is enormous size
variation in the genus. There are leafy sub shrubs,
true shrubs, and geophytes that have almost all
their mass underground, with only deciduous
leaves above ground when growth conditions are
favorable.
As with most tropical genera, Monadenium are
sensitive to cold temperatures, and particularly to
combined cold and wet conditions. It pays to keep
them dry during their winter dormancy, and to
bring them out of dormancy with some care to
keep the roots from rotting in the early spring.
Propagation of Monadenium is similar to
Euphorbia. Cuttings can be made from the stem
succulent species. When they
are fully dry, they will root and
form typical plants. Cuttings
should be taken when plants are
in full growth, doing best when
taken in early summer.
Shown at left is Mona-denium
trinerve a tuberous species from
Kenya, just starting spring
growth.
Jatropha is a tropical and subtropical
genus, with members in
both the old world and new.
Jatropha podagrica
Jatropha are generally shrubs, with natural heights
of a few feet. Some have tuberous roots or
swollen bases, particularly when young while
others have thick semi-succulent branches. Most
are border line succulents, with deciduous, nonsucculent
leaves. Several have become world
wide cultivated plants, grown for their ornamental
and medicinal properties.
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Jatropha podagrica (Mexico) in a garden
in Southern India
Jatropha sp.
Many of the shrubby species can be pruned into
bonsai-like forms and maintained in this condition
for years.
Noteworthy species
Monadenium elgans, a fast growing shrubby
succulent with peeling brown bark, white veined
green deciduous leaves with red edges. Prune
regularly to keep it in shape and size.
Monadenium spinescens another fast growing
species. Great leaves and bark.
Monadenium trinerve is one of the more difficult
geophytic species. It loses its leaves with the onset
of cold weather, and often the caudex before
winters end, leaving only an empty pot. It is
worth growing, but needs a warm greenhouse.
Jatropha podagrica is readily available, but not
the easiest to keep alive. Keep it dry after it loses
it leaves.
Jatropha cinera, another Mexican and Baja plant
is a fast growing shrub. It need regular pruning to
keep it under control, but can make a spectacular
specimen.
Jatropha curcas is Mexican and Central American
in origin, but is grown world wide for its seeds
which have medical uses. People are regularly
poisoned by improper preparation, but it is a
wonderful species to grow.
Jatropha gossypiifolia a tropical American
species has been naturalized as an ornamental
plant around the world. Easy to grow from seed, it
has wonderful red-green leaves in late summer and
early fall.
Tom Glavich August 2007