Adenium
obesum, DESERT ROSE - Ornamental
Adenium obesum
is a species of flowering plant in the dogbane family, Apocynaceae, that is native to the Sahel regions, south of the
Sahara (from Mauritania and Senegal to Sudan), and tropical and subtropical
eastern and southern Africa and Arabia. Common names include Sabi star, kudu,
mock azalea, impala lily and desert rose.
It is an evergreen or drought-deciduous succulent shrub
(which can also lose its leaves during cold spells, or according to the
subspecies or cultivar). It can grow to 1–3 m (3.3–9.8 ft) in height,
with pachycaul stems and a stout, swollen basal caudex. The leaves
are spirally arranged, clustered toward the tips of the shoots, simple entire,
leathery in texture, 5–15 cm (2.0–5.9 in) long and 1–8 cm
(0.39–3.15 in) broad. The flowers are tubular,
2–5 cm (0.79–1.97 in) long, with the outer portion 4–6 cm
(1.6–2.4 in) diameter with five petals, resembling those of other related
genera such as Plumeria and Nerium. The flowers tend to red and
pink, often with a whitish blush outward of the throat.
Adenium obesum is a popular houseplant and bonsai in temperate regions. It requires a sunny
location and a minimum indoor temperature in winter of 10 °C (50 °F).
It thrives on a xeric watering
regime as required by cacti. A. obesum
is typically propagated by seed or stem cuttings. The numerous hybrids are
propagated mainly by grafting on to seedling rootstock. While plants grown from
seed are more likely to have the swollen caudex at a young age, with time many
cutting-grown plants cannot be distinguished from seedlings. Like many plants, Adenium
obesum can also be propagated in vitro using plant tissue
culture.
In
most cases the seeds are formed by self pollination. Seeds explode and are
carried by its wings as parachute and disperse.
Seed
propagated plants mostly give single petal pink flowers. Double are brought
either through grafting or Emasculation.
EMASCULATION
Emasculation
involves the removal of stamens from bisexual flowers of the
female parents in order to avoid self-pollination in these flowers. It is done
before the anthers are mature.
If in a
condition the female parent bears bisexual flowers, then elimination of anthers
from the flower bud before the anther dehisces by means of a pair of forceps (a
large instrument with broad blades) is necessary. And this step is known as emasculation.
In a
process called bagging emasculated flowers are covered with a bag to prevent
contamination of its stigma with unwanted pollen.
However
if the female parent produces unisexual flowers, there is no requirement for
emasculation.
Emasculation and Adanium
This
process is best suited for Adanim to develop different colours and shades in
flowers. The entire process is illustrated in the photographs.
