Euphorbia ammak grows in Yemen and Saudi Arabia in an altitude range
covering 1000 to 2000 and possibly as high as 2500 metres above sea level. It grows
in rockier areas in planes and on steep hillsides and thorny bush-lands where
it has now become scarce, particularly in Saudi Arabia and South Yemen,
although it remains common in places in North Yemen. Euphorbia ammak is
a striking Euphorbia of massive stature that is a large, tree-like Euphorbia growing
up to 10 metres tall with a short trunk and is superficially similar to some
new world Cacti. They have stout stems about 10-15 centimeters wide with
branches starting at about 60 centimeters that arch upwards that have thick
ribs that are undulate and are usually four-winged. They are covered with spines
about one centimeter long. They occasionally produce leaves near the top of
each branch as well as yellow-green flowers. These large examples were part of
what we have called the Euphorbia Forest near Taif where hundreds of Euphorbias
grow n the steep hillsides with a number being very large tree like examples
and others just single stands. This plant is a favourite for Arabian
Golden-winged Grosbeak with this area looking particularly good for the
species.