Natural History - Madagascar - page 88

variableinform(fromlowleafysucculentstotalltree-likeplants),leafshape,sizeandcol-
our. Kalanchoe flowers have parts in multiples of four - four connected petals forming a
tube,foursepals,fourcarpalsandeightstamens-whereasmostotherCrassulaceaeflowers
have parts in multiples of five. In Madagascar the largest species (eg: K. arborescens, K.
beharensis, K. grandidieri ) tend to be restricted to the semi-arid regions of the south and
southwest, while the smaller species occur mostly in the more humid areas up to 2,000m.
Adenia is a genus of about 150 species in the passionflower family. Most are deciduous
vines, climbing with the aid of tendrils, extending from a swollen stem base. They are
usually dioecious (either male or female) with inconspicuous creamy greenish flowers and
fruit that's often vividly coloured when ripe.
Uncarina is an endemic genus of 13 species in the Pedialaceae family. The plants are de-
ciduous shrubs or small trees up to 8m tall with a substantial underground tuber. Flowers
may be yellow, white, pink or violet, and the fruits are large capsules covered with numer-
ous, ferociously hooked thorns, which aid dissemination by attaching to the hairy coats of
animals.
Cyphostemma (familyVitaceae)isagenuswithover300species(aminorityofwhichare
succulent). Twenty-four occur in Madagascar. Cyphostemma sakalavense is bottle-shaped
with a stem up to 3m tall. It can be found on the limestone rocks of the tsingy in northwest
Madagascar.
Senecio is a genus of leaf succulents, existing essentially as a collection of swollen leaves
sprouting from the earth. The leaves are often ornamental, tinged with terracotta and bear-
ing harsh spines, but also display showy red flowers during times of drought.
PALMS Madagascar is home to one of the world's richest palm floras. There are around
170species-threetimesmorethanintherestofAfricaputtogether-and165oftheseare
found nowhere else.
A lack of large herbivores in Madagascar has left its palms - with no need for defences
-spinelessandwithoutpoisons.Pollination ismostlybybeesandflies,butsomehavetiny
flowers to entice unknown insect guests. For seed dispersal lemurs are often employed.
Ring-tailed,black,redruffedandbrownlemursallassistinscatteringtheseeds.Thebright
colours of some fruits serve to attract birds and forest pigs, while the handful of African
palms, which normally use elephants as dispersers, presumably make do with zebu.
The dominance of species with Asian relatives betrays the fact that Madagascar severed
with India millions of years after it broke away from African shores.