|
|
Subfamilies:
CRASSULOIDEAE, SEDOIDEAE,
COTYLEDONOIDEAE, KALANCHOIDEAE, ECHEVERIOIDEAE, SEMPERVIVOIDEAE. According
to some botanists only two of them are to be considered subfamilies:the
Crassuloideae and the Sedoideae; the latter should be then
divided into two tribes, Kalanchoeae and Sedeae divided
in turn into subtribes.
Habitat: South Africa, Madagascar, the Mediterranean, the Canary
Islands, Europe, Mexico. These plants, quite popular among growers, are
widespread in the wild and occur in diverse habitats, from deserts to
swamps, from the torrid heat to the glacial cold, concentrated mainly in
warm and dry areas. They have adapted to many different environments and
managed to survive very harsh conditions developing sophisticated strategies
such as the CAM cycle.
Description: these plants may be covered with hairs, sometimes soft
and woolly to the touch, or have a powdery, waxy, witish bloom on the
surface (pruinose). They come in a variety of forms, colours and leaf
shapes. Generally the flowers have a definite number of sepals and petals,
stamens and carpels; the fruit is a follicle. Some species are
winter-flowering, others bloom in the spring or late summer. Most European
species are hardy. Some can be annual or biennial.
Soil: basic mix; species with climbing or shrubby habit need a large
container.
Location: they enjoy a very bright site, normally in full sun, and
fresh air during growth.
Temperature: tropical and subtropical species need to be kept at a
minimum between 7 and 10°C (45-50°F) particularly when it comes to
Madagascar’s species.
Water: average, but should the temperature be 8°C (46°F) or above
sprinkle some water from time to time to avoid water stress.
Cultivation tips: easy; seeds may be collected by wrapping the
inflorescence in some paper or fine net but they are somewhat difficult to
germinate. The use of the insecticide ‘Malathion’ damages the leaves because
it dissolves the waxy cuticle; use systemic products which enter the plants
via the roots (Orthene for example). They’re easily propagated by stem or
leaf cuttings (a whole leaf or a piece of it). The leaves may turn a
purplish or brownish red as a response to strong light when grown in full
sun. The species that develop stems with a woody base are summer-growing and
should be kept dry at a minimum of about 8°C (46°F). On the other hand, the
species with a succulent stem grow during the winter and rest in the summer
so they need a bright site and not too low winter temperatures while they
should be kept dry during the warm months. Herbaceous species require bright
indirect light and little water all year round.
Main genera: Adromiscus (winter-resting, Namibia and South
Africa), Aeonium, Briophyllum (easy to propagate by rooting plantlets
formed on the edges of the leaves called propagules), Cotyledon,
Crassula, Dudleya, Echeveria, Graptopetalum, Greenovia, Jovibarba, Kalanchoe
(minimum temperature 10°/50°F), Monanthes, Orostachys, Pachyphytum,
Sedum (can be grown outdoors), Sempervivum, Tacitus, Tylecodon
(winter-growing; supply water when the new growth appears then stop when the
leaves are shed), Umbilicus.
   |
|
|
